Over the years, we have been a witness to the astounding evolution in the industry and a participant in the crusade for sustainable development. As a part of a contemporary design-led architecture studio, focused on low energy and low embodied carbon designs, I feel an enormous responsibility in driving the industry towards ‘net zero’. The concept of net zero, a balance between the amount of greenhouse gas emissions produced and removed from the atmosphere, has been thrust upon us as an urgent requirement, yet its fulfilment remains elusive. This blog aims to unravel the architecture industry’s ongoing quest for sustainability and provide insight into the pressing need for a decisive shift from the status quo towards innovative, carbon-conscious design practices.
Herbert Paradise in Kensal Rise designed by RISE Design Studio is a low energy home
Chapter 1: Setting the Scene: Sustainability in the Construction Industry
Over the years, architects, engineers, builders, and other professionals within the built environment have been operating under the banner of progressive sustainability. However, in reality, we have merely sustained and maintained the status quo. The construction industry’s dependency on conventional practices threatens to jeopardize the environment and the needs of current and future generations. To sustain our trajectory of consumption and waste without transforming our methods is a recipe for disaster. Change isn’t just necessary; it’s imperative.
Chapter 2: A Wake-up Call: The Climate Change Act and the Environmental Emergency
The UK Government’s Climate Change Act in 2008 marked the nation’s commitment to reducing greenhouse gas emissions by 100% of 1990 levels by 2050. Despite this, the commitment to sustainability remained rhetoric for many industries, including the built environment, agriculture, and transport. Their collective output levels remain comparable to 1990, with a mere 40% drop in emissions attributed primarily to the energy sector.
Bethany and Imran on site during construction of Herbert Paradise in Kensal Rise, NW London
Chapter 3: The Silent Culprits: Construction Emissions
Alarmingly, the construction, operation, and maintenance of the built environment contribute to 45% of total UK carbon emissions. Additionally, construction and demolition of buildings contribute to a whopping 32% of landfill waste. It’s time to shift our focus from a short-term perspective to a comprehensive lifecycle approach, addressing the construction process, operational phase, and eventual decommissioning of the structures we create.
Chapter 4: The Art of Accounting for Carbon
According to the UK Green Building Council, 10% of total UK emissions originate from the construction process alone. However, the carbon footprint of a building extends beyond construction to include the extraction, manufacture, and transportation of materials, on-site emissions, repair and restoration, and the potential for material recycling or landfilling. The intricacy of this process calls for transparent and accurate accounting, ensuring that undesirable carbon values aren’t ‘greenwashed’.
Ice Cream House in Hampstead, North London, is a low energy home which includes an array of sixteen Solar Panels on the rear outrigger roof
Chapter 5: Embodied Energy and Carbon Conscious Material Choices
A key aspect of reducing carbon output involves re-evaluating our material choices. Traditionally, the architecture industry has relied heavily on materials such as steel and concrete. These materials have high embodied energy due to their extraction, production, and transportation processes, contributing significantly to carbon emissions. Therefore, exploring alternative materials with lower embodied energy is crucial to achieving our net-zero goal.
Chapter 6: Embracing Timber Construction
Cross-Laminated Timber (CLT) construction, as a carbon-negative alternative to steel and concrete, is slowly gaining acceptance in the industry. Architectural practices such as RISE Design Studio and Waugh Thistleton are trailblazers in this area. CLT offers intriguing possibilities with its inherent flexibility in design and compatibility with low carbon strategies. It presents a promising path towards sustainable architecture, despite the lingering concerns around fire safety for high-rise buildings.
The Lexi Cinema in Kensal Rise, NW London, is the first cinema to use an ASHP and MVHR to control the internal climate of the auditorium
Chapter 7: Timber – The Sustainable Promise
Despite the regulation against the use of combustible materials in new housing schemes over 18m post-Grenfell, the potential benefits of CLT cannot be ignored. Its attributes include speed of housing delivery, carbon capture, fire and acoustic performance, and embodied energy. Notably, it provides the opportunity for carbon sequestration, further contributing to reducing the overall carbon footprint of a building.
Chapter 8: Beyond Energy Efficiency: The Quest for Carbon-Positive Building
While it’s crucial to reduce embodied carbon and energy in use, our ambition should extend beyond achieving net-zero energy buildings to creating ‘carbon positive’ ones. Carbon-positive buildings not only consume less energy than they produce but also incorporate materials that actively remove carbon from the atmosphere. Our ultimate goal should be to design and build structures that contribute positively to their environment and leave a beneficial legacy for future generations.
Ice Cream House in Hampstead includes an ASHP, MVHR, Airtightness, high-performance insulation and glazing
Chapter 9: Innovating with New Sustainable Materials
Technological innovation and research are fostering the development of new sustainable materials. For instance, researchers at Washington State University have developed plant-based insulation that outperforms synthetic equivalents like Styrofoam. Similarly, companies like BioMason and StoneCycling are revolutionising the production of bricks, using environmentally friendly and recycled materials. Such developments are not only reducing the industry’s carbon footprint but also challenging the conventional norms of material usage.
Chapter 10: Reimagining the Future of Construction
To transition towards sustainable construction, a paradigm shift is required at all levels of the industry. We must shed preconceptions of what a building should look and feel like and bravely innovate to ensure optimal performance. Clients and architects alike need to align their objectives with the overarching goal of environmental stewardship. Only by embracing change and challenging the status quo can we hope to meet our sustainability goals.
In conclusion, as we stand at the crossroads of sustainability, the architecture industry has an unprecedented opportunity to lead the charge towards a net-zero future. We must be pioneers, willing to venture beyond the comfortable realms of traditional practices and fearlessly embrace innovation. The journey won’t be easy, but the rewards – a healthier planet and a brighter future for generations to come – are undoubtedly worth the challenges we will face along the way.
If you would like to talk through your project with the team, please do get in touch at mail@risedesignstudio.co.uk or give us a call at 020 3290 1003
At RISE Design Studio, we’ve always championed a sustainable approach, especially in recent years when the climate crisis is more pressing than ever. As someone who’s seen the tide change and observed the inertia in adoption, let me take you through the essence of creating low-energy, low-embodied carbon designs.
Mill Hill House in North London, designed with Passivhaus Principles
1. Understanding the Net Zero Context in Construction
In 2008, the UK emerged at the forefront of environmental consciousness by introducing the Climate Change Act, a legislation aimed at steering the nation towards a more sustainable future. The vision was clear: to achieve a substantial reduction in greenhouse gas emissions, targeting an ambitious 100% cut from the levels recorded in 1990 by the time we reach 2050. This commitment reflected not only a local desire for change but also resonated with international climate accords and set a benchmark for other nations to potentially emulate.
However, navigating the path to net zero proved far more intricate than setting a numerical target. Across industries, the challenge lay in deciphering how to transition from long-standing practices, deeply entrenched in the heart of our economy, to newer, greener alternatives. The construction industry, responsible for a significant portion of the UK’s carbon emissions, was no exception. While on paper the intentions seemed promising, the underlying complexity of this transition was evident in the nation’s real-time progress.
Fast-forward to 2019, and the urgency of the situation intensified. Despite a decade having passed since the initiation of the Climate Change Act, the UK Government found itself declaring an ‘environment and climate emergency’. While some sectors showed marked improvement, others lagged, making it evident that incremental changes were insufficient to meet the monumental task at hand.
This juxtaposition of intention and outcome brings us to a pivotal juncture in our sustainable journey. The question now looms large: have we been merely sustaining — continuing practices that, although perhaps slightly improved, are essentially a perpetuation of the status quo? Or are we genuinely evolving, pushing boundaries, innovating, and truly revolutionising the way we think about and practise construction?
Addressing this question necessitates a thorough introspection of the construction sector. Are the strategies adopted merely superficial measures designed to tick boxes and fulfil statutory requirements? Or do they signify a genuine commitment to change, marking the evolution of practices that integrate sustainability at their core?
Such introspection will be fundamental as we move forward. The world is ever-evolving, and the challenges we face in the next decade might be entirely different from those we grapple with today. Thus, understanding the broader context of ‘net zero’ in construction is not just about meeting targets set in the past, but about preparing for a future that demands sustainability as its foundation. We must build not just with today in mind but with an eye on tomorrow, ensuring that our strategies, practices, and ethos are adaptable, resilient, and truly sustainable.
Herbert Paradise in North West London, designed with EnerPHit Principles
2. Decoding Construction Emissions
The construction sector has always been a cornerstone of urbanisation and infrastructure development. As our cities expand and our infrastructure needs grow, so does the role of construction in shaping our environment. But with great responsibility comes the imperative to be accountable, and the statistics paint a startling picture of the sector’s impact on the environment.
2.1 The Carbon Footprint
With 45% of the UK’s carbon emissions attributed to the construction, operation, and maintenance of buildings, it’s evident that this sector is one of the primary contributors to the nation’s greenhouse gas outputs. These emissions can be traced back to various stages of a building’s lifecycle:
Materials Production: The extraction, processing, and transportation of building materials are energy-intensive processes. Concrete, for instance, is one of the most widely used construction materials, and its production is responsible for a significant portion of these emissions.
Construction Process: The activities on construction sites, from machinery operation to waste generation, contribute to the sector’s carbon footprint. Energy consumption in these phases, especially if sourced from non-renewable resources, further aggravates the emission issue.
Building Operation: Once constructed, buildings continuously consume energy, primarily for heating, cooling, and lighting. If this energy is drawn from fossil fuels, it significantly adds to the carbon load.
Maintenance & Refurbishment: Regular maintenance activities, especially those requiring extensive material inputs or energy consumption, play a part in the ongoing emissions from the built environment.
2.2 The Waste Dilemma
Waste generation is another critical area of concern. A striking 32% of landfill waste in the UK originates from construction and demolition activities. This not only represents a tremendous waste of resources but also has environmental implications. Landfills can lead to groundwater contamination, produce methane (a potent greenhouse gas), and destroy natural habitats.
Additionally, the fact that 13% of products procured for construction purposes are never used underscores a deeply entrenched inefficiency in the sector. This wastage speaks volumes about the need for better planning, forecasting, and sustainable procurement practices.
2.3 Paving the Way Forward
To effect genuine change, the construction sector must delve deeper than surface-level solutions. A systemic transformation is required, starting from the design phase right through to construction, operation, and eventual decommissioning.
Sustainable Design: Architectural and engineering designs should prioritise sustainability. This might involve the use of environmentally friendly materials, passive solar design, and energy-efficient technologies.
Resource Efficiency: By re-evaluating procurement strategies, using materials judiciously, and adopting recycling practices, the construction sector can drastically reduce waste and increase efficiency.
Transition to Clean Energy: Embracing renewable energy sources for construction operations and building functionalities can substantially mitigate carbon emissions.
In essence, the construction sector’s road to sustainability demands more than cursory changes. It’s about overhauling traditional practices, adopting innovative solutions, and committing to a vision where the built environment harmoniously coexists with the natural world.
The team at RISE Design Studio
3. Addressing Embodied Carbon: The Real Devil in the Details
When one speaks of carbon emissions in construction, the focus predominantly hovers over operational energy – the energy consumed during the usage phase of a building. However, a deeper dig reveals a far more insidious element: embodied carbon. This form of carbon refers to the greenhouse gas emissions produced during the entire life cycle of building materials, right from extraction to end-of-life. It’s the devil in the details, lurking beneath our commonly held perceptions of construction’s environmental impact.
3.1 Defining Embodied Carbon
Embodied carbon can be split into two primary categories:
Upfront Embodied Carbon: This encompasses emissions from the extraction, processing, manufacture, and transportation of materials used in construction. These emissions occur before the building even comes into existence.
End-of-life Embodied Carbon: Emissions in this category arise from the repair, renovation, deconstruction, and disposal processes after the construction phase.
Both forms of embodied carbon are equally vital, and together they account for a significant proportion of a building’s total carbon footprint.
3.2 The Overshadowed Emissions
There are several reasons why embodied carbon is often overlooked:
Eclipsed by Operational Carbon: The ongoing energy use in buildings, particularly in heating, cooling, and lighting, often overshadows embodied carbon because of its recurrent and visible nature.
Complexity in Measurement: Calculating embodied carbon is challenging due to the varied lifecycle of materials, differences in transportation methods, and the myriad processes involved in material creation.
Lack of Awareness: A comprehensive understanding of embodied carbon is still nascent in many industry circles. As a result, its importance is often diminished in mainstream discussions.
3.3 Unveiling the Hidden Impact
Several construction practices and phases contribute to the stealthy rise of embodied carbon:
Material Choice: Materials like concrete and steel, while sturdy and reliable, come with a hefty carbon price tag due to their manufacturing processes.
Transportation: Long supply chains and the heavy machinery involved in transporting materials amplify the carbon footprint.
Construction Techniques: Traditional construction methods might not always be the most carbon-efficient.
Maintenance and Refurbishment: The frequent replacement of components, the use of non-sustainable materials for repairs, and inefficient restoration methods add to the carbon load.
Waste Management: Inadequate recycling and reuse practices during deconstruction can lead to unnecessary emissions during waste disposal.
3.4 Charting a New Course
Addressing embodied carbon necessitates a multi-pronged approach:
Material Innovation: Research and development into low-carbon alternatives for traditional building materials can significantly reduce upfront emissions.
Efficient Supply Chains: Streamlining transportation and sourcing materials locally can diminish the carbon emissions from logistics.
Lifecycle Thinking: Architects, engineers, and builders need to adopt a lifecycle perspective, considering the environmental impact of materials from cradle to grave.
Education and Advocacy: Spreading awareness about embodied carbon and its implications is crucial. Only with widespread knowledge can industry-wide changes be effected.
In summary, while operational energy remains a critical area of focus, a holistic approach that also accounts for embodied carbon is indispensable. Recognising and addressing this hidden devil in the details is imperative for a truly sustainable construction sector.
4. Redefining Materials: Beyond Steel and Concrete
The skyline of our modern cities, with its towering skyscrapers and sprawling infrastructure, tells a tale of steel and concrete, two materials that have become synonymous with construction. Their strength, durability, and versatility have made them the default choice for most construction projects. Yet, as we delve deeper into the 21st century, we are confronted with the undeniable environmental costs these materials incur. But with companies like Solidia transforming the very essence of such materials, and with the burgeoning rise of alternative construction resources, we might be on the cusp of a materials revolution.
4.1 The Environmental Weight of Steel and Concrete
Steel and concrete, while architecturally transformative, have environmental repercussions:
Carbon-Intensive Production: The production of steel requires the smelting of iron at high temperatures, usually achieved through coal, releasing a significant amount of CO2. Similarly, the production of cement, a key component of concrete, is responsible for approximately 8% of global carbon dioxide emissions.
Resource Depletion: Large quantities of raw materials, such as iron ore for steel and limestone for cement, are extracted, which impacts ecosystems and depletes finite resources.
Waste Production: The production processes, particularly for steel, result in by-products and waste, which can be challenging to manage.
4.2 Pioneering Change: The Solidia Example
Solidia’s approach exemplifies how innovation can alter the landscape of traditional materials. By changing the chemical process in cement production, Solidia not only reduces CO2 emissions but also uses CO2 in the curing process of concrete. Such advancements showcase the potential for revamping old practices for a greener future.
4.3 Beyond the Familiar: Exploring Alternative Materials
While innovations in concrete and steel are welcome, diversifying our materials palette is crucial:
Timber: Modern engineered timber products, like cross-laminated timber (CLT), offer strength comparable to traditional materials but with a fraction of the carbon footprint. Trees, as they grow, sequester carbon, making timber a carbon-negative material.
Bamboo: Rapidly renewable and incredibly sturdy, bamboo can be a sustainable alternative for various construction needs, especially in regions where it naturally grows.
Hempcrete: Made from the hemp plant’s woody core and a lime-based binder, hempcrete is a lightweight, insulating, and carbon-sequestering material.
Mycelium: This fungal material is organic, fully compostable, and can be grown into various moulds, making it a potential insulator or structural element.
Recycled and Reclaimed Materials: Utilising materials from demolished structures or repurposing waste products can drastically cut down on emissions from new material production.
4.4 The Road Ahead: Integration and Acceptance
The future of construction doesn’t necessarily lie in abandoning steel and concrete altogether but in integrating them with a broader set of sustainable materials. Challenges remain:
Regulations and Standards: New materials need to meet safety and performance standards, requiring rigorous testing and approvals.
Industry Mindset: Long-held beliefs and practices need to be reconsidered, which requires education, training, and a willingness to innovate.
Cost Implications: Some sustainable materials are currently more expensive than their traditional counterparts, making them less attractive for budget-tight projects.
Supply Chain Development: New materials necessitate new supply chains, which can pose logistical challenges initially.
However, with the environmental imperative clearer than ever, the shift towards more sustainable materials is not just desirable but essential. As the construction industry redefines its relationship with materials, it takes a significant step towards a more sustainable, green, and innovative future.
Red Arches House in Kensal Rise, North West London, designed to Passivhaus Standards
5. Embracing Timber: An Old Solution to a New Problem
Timber, once the primary material in many traditional construction practices, seemed to have been overshadowed by the rise of steel and concrete in modern times. However, as the quest for sustainable construction materials becomes imperative, timber is making a significant comeback. Central to this resurgence is Cross-Laminated Timber (CLT), a modern engineered wood product that is redefining the construction landscape. Pioneering firms such as RISE Design Studio and Waugh Thistleton are at the forefront of this timber revolution, exemplifying the perfect amalgamation of tradition, innovation, and sustainability.
5.1 The Science of Cross-Laminated Timber (CLT)
CLT is not just any regular wood. It’s a multi-layered wood panel made by stacking layers of lumber orthogonally and bonding them with structural adhesives. This unique structure provides CLT with:
Strength: Comparable to traditional building materials, making it suitable for multi-storey structures.
Fire Resistance: The dense, compact layers char slowly, providing a natural barrier to fire.
Thermal Efficiency: Timber’s natural insulating properties make CLT structures energy-efficient.
5.2 The Environmental Advantage
Beyond its structural merits, CLT stands out for its sustainability:
Carbon Sequestration: Trees absorb carbon dioxide as they grow. Even when transformed into CLT, the carbon remains locked in, making timber a carbon-negative material.
Renewability: Forests, if managed responsibly, can provide a continual source of timber without depleting the Earth’s resources.
Reduced Waste: CLT panels can be precision-cut off-site, leading to minimal waste during construction.
5.3 Projects in the Limelight: Dalston Works
The transformative power of timber becomes evident when one examines architectural marvels like Dalston Works:
Dalston Works: Showcasing the versatility of timber, this project intertwines modern design with sustainable practices. Its distinctive appearance, combined with energy efficiency, makes it a beacon of future-forward architecture.
5.4 Timber’s Potential in Modern Architecture
The adaptability of timber is not just about its inherent properties but also about the innovative minds that mould it. Leading design studios are:
Pushing Design Boundaries: Exploring intricate forms, curves, and overhangs previously thought challenging with timber.
Integrating with Other Materials: Combining timber with glass, steel, or concrete to produce hybrids that maximise the strengths of each material.
Exploring Prefabrication: Taking advantage of timber’s suitability for off-site construction to enhance efficiency and reduce construction times.
5.5 The Path Forward
While the merits of timber, particularly CLT, are compelling, it’s essential to approach timber construction with a balanced perspective. Responsible forestry, innovative design, and public perception are areas that require attention. With the right commitment, however, timber can indeed bridge the gap between our architectural ambitions and our environmental responsibilities.
In a world grappling with environmental challenges, timber’s re-emergence in the construction arena offers a glimmer of hope. By marrying the old and the new, it serves as a poignant reminder that sometimes, solutions to our most pressing issues can be found by looking back even as we march forward.
6. Debunking the Myths: Timber and Safety
The catastrophic events at Grenfell Tower undoubtedly cast a dark shadow over the use of certain materials in construction, leading to heightened concerns around fire safety. While the emphasis on safety is necessary and commendable, it’s vital to ensure that accurate information drives public perception and policy decisions. One such material under scrutiny is timber. However, it’s essential to separate fact from fiction, particularly when considering the benefits and risks associated with timber, especially Cross-Laminated Timber (CLT).
6.1 Timber: The Burning Myths
Combustibility: Timber is often viewed as a highly flammable material. While it’s true that timber can burn, its combustion properties, especially in thick sections like those in CLT, are predictable. When exposed to fire, timber forms a protective char layer that insulates the internal layers, slowing down the burning rate.
Fire Spread: Another misconception is that timber can cause rapid fire spread. In reality, CLT panels, due to their compactness, burn at a much slower rate than expected, often providing more resistance than some other conventional materials.
6.2 The Science Behind Timber Fire Safety
Several factors determine timber’s behaviour in fires:
Density: Denser woods tend to have a slower charring rate, providing an added layer of protection.
Moisture Content: Dry timber is more prone to ignition, but once a char layer forms, moisture content has less influence on the burning rate.
Thickness: Thicker CLT panels take longer to burn through, offering extended protection in the event of a fire.
6.3 Sustainable Forestry: A Double Boon
Well-managed timber forests play a dual role:
Endless Raw Material Supply: With sustainable forestry practices, we can ensure a continuous supply of timber without degrading our environment.
Carbon Sequestration: As trees grow, they absorb carbon dioxide, making forests a vital carbon sink. By turning these trees into CLT panels, we lock in that carbon, further reducing our carbon footprint.
6.4 Regulatory Response: Ensuring Safety
While the inherent properties of timber offer fire resistance, it’s paramount that the regulatory environment also reflects best practices:
Strict Building Codes: These should emphasise fire safety regardless of the construction material.
Regular Inspections: Buildings made from timber should undergo frequent safety inspections to ensure they remain up to standard.
Fire Safety Education: Educating both the construction industry and the public on the safe use of timber can alleviate unfounded fears.
6.5 Beyond Safety: The Holistic Benefits of Timber
While safety is paramount, it’s also essential to view timber in a broader context. Its sustainability, aesthetic appeal, and overall contribution to well-being make it a material that offers benefits well beyond just structural properties.
In conclusion, while the Grenfell tragedy rightly makes us question and re-evaluate our construction practices, it’s crucial that our responses are informed and balanced. Timber, especially in its engineered forms like CLT, presents an opportunity to build sustainably and safely. By debunking myths and investing in robust safety measures, we can ensure that timber continues to play a pivotal role in our built environment.
Imran and Bethany discussing proposals for a sustainably driven residential project in South London
7. Beyond Conventional Wisdom: Challenging Green Standards
In recent times, the race towards a sustainable future has led to a surge of “green” labelled products and construction methodologies. While many of these standards have paved the way for increased environmental awareness, the challenge now lies in discerning between what is truly sustainable and what might merely be ‘greenwashed’ or superficially eco-friendly.
7.1 The Green Mirage: Unmasking Greenwashing
The term ‘greenwashing‘ describes the process by which organisations misleadingly promote their products, aims, or policies as environmentally friendly when, in reality, they might not be. In the realm of construction, this can manifest in several ways:
Vague Claims: Terms like ‘eco-friendly’ or ‘all-natural’ without clear definitions or contexts can be misleading.
Hidden Trade-offs: A product might be marketed as green based on a single environmentally friendly attribute, overshadowing other potentially harmful impacts.
Lesser of Two Evils: Positioning a slightly ‘greener’ version of a notoriously unsustainable product as the ideal choice.
7.2 Evaluating the True Impact: Life Cycle Assessments
To genuinely gauge the sustainability of a material or method, it’s crucial to perform a Life Cycle Assessment (LCA). This comprehensive review examines the environmental impact of a product throughout its entire lifespan – from raw material extraction to disposal.
Cradle-to-Grave: This approach examines the total environmental impact from material extraction to the end of the product’s life.
Cradle-to-Gate: This evaluates the environmental implications from material extraction up to the point where the product leaves the production facility.
Cradle-to-Cradle: This considers the entire product life cycle but with a focus on recycling or repurposing materials, rather than disposal.
While the materials used play a significant role, true sustainability encompasses a broader approach:
Design Philosophy: Architectural designs that incorporate passive solar heating, natural ventilation, and other green principles can significantly reduce a building’s environmental footprint.
Operational Efficiency: The way buildings are utilised and maintained can dramatically impact their overall sustainability.
Community Engagement: Local sourcing of materials and involving the community in construction projects can foster sustainable development and social responsibility.
7.4 Setting the Bar Higher: Next-Generation Green Standards
For the construction industry to evolve sustainably, it’s essential to challenge and refine the green standards regularly:
Transparent Certifications: Clear criteria and rigorous third-party verifications for green labels can prevent misleading claims.
Innovative Benchmarks: Encouraging the research and adoption of innovative solutions can pave the way for more robust green standards.
Stakeholder Involvement: Engaging industry experts, environmentalists, and the public can ensure diverse perspectives shape sustainability standards.
7.5 Embracing Authentic Sustainability
The path to a genuinely sustainable future requires a shift in mindset. Rather than merely ticking boxes or achieving green labels, the construction industry should be guided by an inherent commitment to minimising environmental harm and enhancing societal well-being.
In conclusion, while current green standards have laid the essential groundwork, the next phase of sustainable construction must challenge, refine, and elevate these benchmarks. Only by aiming higher and demanding authentic sustainability can we hope to construct a future that’s not just built on solid foundations, but is also harmoniously intertwined with the environment.
8. The Dawn of Sustainable Materials and Technologies
In the past, the construction industry primarily revolved around traditional materials and methods, driven by tried-and-tested techniques. However, as environmental concerns have heightened, there’s been a transformative shift towards more sustainable options. Universities, startups, and leading businesses are pioneering new materials and technologies that not only challenge the status quo but promise a more sustainable future without compromising on performance.
8.1 Plant-Based Insulation: A Breath of Fresh Air
Washington State University has been at the forefront of developing plant-based insulation. Unlike conventional insulation, which often contains synthetic and potentially harmful components, plant-based alternatives offer:
Reduced Carbon Footprint: Derived from renewable resources, the production of plant-based insulation emits fewer greenhouse gases.
Health Benefits: Natural materials reduce the risk of off-gassing, which is associated with various health concerns.
Biodegradability: At the end of its life cycle, plant-based insulation can degrade naturally, avoiding the landfill challenges posed by synthetic counterparts.
8.2 BioMason: Building the Future, One Brick at a Time
BioMason’s groundbreaking approach involves “growing” bricks from organic material. This innovative method:
Eliminates the Need for High-Temperature Kilns: Traditional brick-making is energy-intensive, often requiring vast amounts of fossil fuels.
Reduces CO2 Emissions: BioMason’s process sequesters carbon dioxide, thus actively reducing the amount of CO2 in the atmosphere.
Offers Design Versatility: As they are grown, these bricks can be customised for different textures, strengths, and sizes.
8.3 StoneCycling: Recycling for Robust Construction
StoneCycling has revolutionised brick manufacturing by using waste materials. Their method:
Diverts Waste from Landfills: By upcycling waste, StoneCycling reduces the strain on landfills.
Diverse Aesthetics: The use of various waste materials results in a unique array of colours and textures for each brick.
Conserves Natural Resources: As the bricks are made from recycled materials, the need for virgin raw materials is drastically reduced.
8.4 The Larger Landscape: Beyond Bricks and Insulation
While the aforementioned technologies are noteworthy, the horizon of sustainable construction materials is vast:
Hempcrete: Made from hemp, lime, and water, Hempcrete provides excellent insulation and is carbon-negative.
Mycelium Composites: Fungi-based materials are not only sustainable but offer unique structural and insulation properties.
3D Printing: This technology allows for precise material use, reducing waste and allowing for the use of recycled or alternative materials in construction.
8.5 The Promise of Tomorrow
The innovations led by institutions like Washington State University and companies such as BioMason and StoneCycling are just the tip of the iceberg. With a growing emphasis on sustainable development, research and investments in this arena are set to soar.
In closing, the dawn of sustainable materials and technologies is not a distant dream but a burgeoning reality. As we continue to explore and embrace these alternatives, we’re not only crafting structures but also moulding a more sustainable, environmentally conscious future.
The Avenue Brick House in Pinner, North London
9. Shaping Tomorrow: Legislation or Nature’s Reckoning?
The push and pull between human-made rules and nature’s undeniable truths have long dictated the way we approach our environment. As the construction industry stands at the crossroads of modernity and sustainability, the driving factors for change have never been more apparent. The decision before us is clear: either adapt proactively through legislation or react defensively against the increasingly severe consequences of climate change.
9.1 The Power of Legislation
Governmental mandates can act as the very catalyst the industry needs to propel towards sustainable change.
Setting Clear Standards: By establishing quantifiable benchmarks for sustainability, governments can ensure a baseline level of environmental responsibility.
Incentivising Green Practices: Tax reliefs, grants, or reduced permit fees for sustainable construction can encourage developers to go green.
Educating the Masses: State-funded programmes can raise awareness about the significance of sustainable construction and its long-term benefits.
9.2 The Wrath of Nature
Ignoring the environment’s cues is no longer an option. Nature’s reckoning is evident in the form of:
Natural Disasters: Increasingly severe weather events, from floods to heatwaves, highlight the immediate need for resilient and sustainable architecture.
Resource Depletion: The scarcity of traditional construction materials is pushing the industry to seek sustainable alternatives.
Ecological Impact: Loss of biodiversity and degraded landscapes are sobering reminders of the toll our construction choices can have on local ecosystems.
9.3 Advocacy in Design
As architects, engineers, and builders, industry professionals are in a unique position to influence sustainable change.
Innovative Blueprints: By prioritising sustainable materials and methods in designs, the industry can pave the way for a new construction era.
Client Engagement: Engaging in open dialogues with clients about the benefits and necessity of green construction can make a substantial difference.
Collaborative Efforts: Partnerships with environmental experts and conservationists can enhance the industry’s understanding and implementation of sustainable practices.
9.4 A Collective Vision
The journey to sustainability is not a solo endeavour but a collective vision. Every stakeholder, from the labourer on the ground to the investor in the boardroom, plays a pivotal role.
Empowering Workers: Training programmes can equip construction workers with the knowledge and skills to implement sustainable practices effectively.
Investment in Research: Financial backing for research into sustainable materials and construction techniques can unlock new possibilities.
Community Involvement: Encouraging community input in construction projects can lead to more environmentally friendly and socially responsible outcomes.
9.5 The Path Forward
While both legislation and nature’s reckoning are formidable forces, the true power lies in our hands. Through conscious choices, unyielding commitment, and a shared vision, the construction industry can and must shape a sustainable tomorrow. The stakes are high, but so too are the rewards: a world where buildings not only serve their occupants but also honour the environment they inhabit.
Douglas House in Kensal Rise, North West London, designed with EnerPHit principles
10. The Path Forward: From Within the Industry
In the throes of an environmental revolution, the construction sector stands at the vanguard of change. While external pressures, from legislation to market demand, play a role, it’s the industry insiders who hold the key to reshaping its future. For the architects, builders, and designers at the helm, leading the charge towards a net-zero future is not only a responsibility but a calling.
10.1 Embracing the In-House Vanguard
Leading by Example: Key industry players should exemplify best practices, both in their designs and on-site operations.
Continuous Education: Regular training and workshops can be conducted to update industry professionals on the latest sustainable methodologies and technologies.
Empowering the Next Generation: Mentorship programmes and internships centred on green construction can foster an environment of growth and knowledge exchange.
10.2 Fostering Collaboration
Open Dialogue: Platforms for discussion can be established, enabling professionals from different disciplines to share insights, troubleshoot issues, and brainstorm innovative solutions.
Partnerships with Academia: Collaborative efforts with universities can lead to research-driven solutions, paving the way for groundbreaking sustainable techniques.
Engagement with Suppliers: Close ties with material suppliers can foster the development of eco-friendly products tailored to the industry’s specific needs.
10.3 Financing the Green Revolution
Green Investment: Industry leaders can push for more financial backing into sustainable construction projects, ensuring their viability and profitability.
Grants and Incentives: Companies can establish grant systems for startups and projects that emphasise sustainability, creating a positive feedback loop of innovation.
Cost-Benefit Analysis: By showcasing the long-term financial and environmental benefits of sustainable construction, the industry can encourage stakeholders to back such projects.
10.4 Nurturing Innovation
R&D Focus: Companies can set aside dedicated funds and resources for research and development, promoting the creation of novel solutions.
Rewarding Creativity: Internal competitions, awards, and recognitions can be established to motivate employees to think outside the box.
Adopting Technology: Embracing technological advancements, such as Building Information Modelling (BIM) and green tech, can drive efficiency and sustainability.
10.5 The Ethos of Change
At the heart of this monumental shift lies a change in ethos. The construction industry needs to move away from the short-term, profit-driven mindset to one that values long-term sustainability and societal benefit. This ethos, while business-centric, should echo the broader societal push for environmental stewardship.
In Conclusion
Our commitment to a sustainable future in the construction sector is a marathon, not a sprint. It demands a holistic reimagining of processes, priorities, and perspectives. By forging ahead with resolve, unity, and vision, the industry can make the dream of a net-zero future an everyday reality. And in this collective endeavour, it’s not the distant policymakers or detached critics who will drive the change, but the passionate architects, builders, and designers at the very heart of the industry.
If you would like to talk through your project with the team, please do get in touch at mail@risedesignstudio.co.uk or give us a call on 020 3290 1003
Here, I aim to give you a deeper understanding of what airtightness is, combining theory with the practicalities we’ve encountered working on the many low-energy retrofit and new build projects we’ve completed.
Proclima Intello tape uses for airtightness on this timber frame house
Chapter 1: Introduction, The Airtightness Imperative
In today’s age of sustainability, the topic of energy efficiency has steadily climbed the agenda of architects, builders, and homeowners alike. Notably, airtightness has emerged as a paramount concern, given its direct correlation with energy loss. Older homes, with their dated construction methods and less effective materials, have historically struggled with energy loss due to air leakage. However, as construction methods have modernised, the magnitude of the problem has only grown more apparent.
1.1 The Evolution of Housing and Energy Loss
To understand the significance of airtightness in contemporary construction, we must first look back. Historically, the construction of homes was more ‘breathable’, primarily due to the materials and techniques employed. These houses, while charming, often had gaps, cracks, and other points of air leakage. The result? Approximately 20% of energy, predominantly from space heating, would be lost due to these imperfections.
However, as society became more environmentally conscious, the methods of construction evolved. Modern homes became insulated havens with double or triple-glazed windows, improved wall insulation, and advanced heating systems. As these improvements reduced other methods of heat loss, the proportion of energy loss attributed to ventilation drastically increased. Today, it’s estimated that ventilation contributes to 35-40% of a home’s energy loss.
1.2 The Modern Paradigm
While our forebears might have been more accepting of a drafty home, modern homeowners are not. Rising energy costs, the push for green technologies, and the demand for energy-efficient homes have highlighted the importance of airtightness. It’s no longer sufficient to slap on a layer of insulation and call it a day. Every joint, seam, and intersection in a building needs scrutiny.
1.3 The Comprehensive Approach to Airtightness
A comprehensive approach to airtightness doesn’t simply focus on sealing gaps. It requires a multi-faceted strategy that includes:
Material Selection: Using advanced materials that inherently reduce air leakage.
Construction Techniques: Employing methods that emphasise the airtight sealing of a building’s envelope.
Mechanical Systems: Implementing controlled ventilation systems, ensuring fresh air intake without energy loss.
Regular Maintenance and Checks: As buildings settle and age, potential problem areas might emerge. Routine checks ensure that a building remains as airtight as the day it was constructed.
In conclusion, as the architectural and construction industries continue to progress, the airtightness imperative will remain central to the dialogue. The benefits, ranging from reduced energy costs to a lower carbon footprint, make it clear that this is not just a trend but a necessary evolution in the way we build and inhabit spaces.
A typical Victorian property in Queen’s Park, North West London
Chapter 2: What is Airtightness and Why is it Crucial?
The notion of airtightness might initially conjure images of sealed containers or vacuum chambers. However, when it comes to the built environment, this term carries a nuanced significance. Airtightness has come to the forefront of architectural discourse, not merely as a buzzword, but as an indispensable criterion for modern design.
2.1 Defining Airtightness
At its core, airtightness speaks to a building’s capacity to prevent unintended air exchange with its surroundings. This doesn’t mean a space void of fresh air, but rather, an environment where the inflow and outflow of air are meticulously controlled. This is measured in terms of air permeability, which quantifies the volume of air (in cubic metres) that leaks per hour through each square metre of the building’s external envelope under specific test conditions.
2.2 The Implications of Air Leakage
When a building is not airtight, it falls prey to the unpredictable whims of the environment. During colder months, warmth from the interior might escape, while in summer, the heat could intrude. This inconsistent interchange:
Compromises Indoor Comfort: Rooms may feel draughty or have fluctuating temperatures.
Increases Energy Consumption: As heating or cooling systems work overtime to compensate for the loss or gain of heat, energy usage escalates.
Elevates Utility Costs: With energy consumption on the rise, utility bills can also see a noticeable uptick.
2.3 Airtightness: A Pillar of Modern Architecture
For an avant-garde design studio such as ours, the principles of airtightness are not just checkboxes in a compliance sheet. They represent the ethos of 21st-century architecture:
Sustainability: With the global push towards eco-consciousness, reducing the carbon footprint of buildings has become paramount. Airtight buildings play a significant role in this pursuit.
Innovation in Design: Modern architecture seeks not just to appease the eye but also to push the boundaries of what’s possible. Incorporating airtightness solutions challenges designers to innovate and redefine building norms.
Holistic Building Performance: Contemporary design recognises that aesthetics and functionality are two sides of the same coin. Airtightness, thus, contributes to a building’s overall performance, enhancing occupants’ comfort and well-being.
2.4 Ensuring Airtightness: An Integral Phase
Ensuring a building is airtight is not an afterthought—it’s an intrinsic part of the design and construction process. This involves:
Detailed Designing: Right from the drafting table, potential air leakage points are identified and mitigated.
Material Specification: Using advanced membranes, sealants, and insulation which help in achieving the desired airtightness levels.
On-site Verification: Employing tools like blower door tests to measure and verify the airtightness of a constructed space.
In summary, as the construction landscape evolves, understanding and emphasising airtightness remains pivotal. It is not just about conforming to standards but sculpting spaces that resonate with the needs and aspirations of our times.
01 Taping of membrane overlapping to underside of ceiling / 02 Airtightness taping around joist ends / 03 Airtightness membrane at the underside of a ceiling with taping around web-joists and other junctions / 04 Airtight membranes installed prior to the installation of internal studwork 05 Specialised seals around ductwork 06 Specialised seals around penetration for wires. Image credit: Passivehouse Plus
Chapter 3: Modern vs. Older Homes: A Comparison
When delving into the domain of building construction and airtightness, it’s tempting to believe that advancements in technology and design inherently make modern homes superior to their older counterparts in every aspect. However, this isn’t always the case, especially when examining airtightness. Contrary to popular belief, some contemporary homes might fall short in this arena when compared to older structures.
3.1 The Architectural Evolution Over Time
The architectural journey, over decades, has been marked by evolving aesthetic preferences, changing materials, and innovations in construction techniques. Historically:
Older Homes: They were often constructed with dense, solid materials, like brick and stone, which naturally provided a certain level of airtightness. The simpler design patterns, with fewer joints and breaks in the structure, minimised air leakage points. Ventilation was usually provided by natural draughts through less refined windows and doors.
Modern Homes: These epitomise a blend of complex designs, large glazed areas, and a vast array of materials. While they offer numerous advantages, the complexity can introduce numerous potential points of air leakage if not meticulously managed.
3.2 The Paradox of Modern Construction
Modern buildings are not inherently flawed, but the challenges they pose in terms of airtightness include:
Varied Workmanship: The quality of construction can fluctuate significantly due to diverse workmanship standards, potentially creating inconsistent airtightness levels across different buildings or even different parts of the same building.
Complex Assemblies: Modern homes often feature intricate design elements—such as larger windows, complex junctions, and multiple material transitions—that can introduce vulnerabilities if not sealed appropriately.
Rapid Construction: The drive to complete buildings quickly can sometimes lead to an oversight in ensuring airtightness.
3.3 Lessons from the Past
While older homes might lack many of the modern amenities and technological advancements, their approach to airtightness, albeit unintentional, offers lessons:
Simplicity: Fewer joints and breaks mean fewer potential leak points. Modern designs can aim for a balance between aesthetic complexity and airtight simplicity.
Use of Natural Materials: Traditional construction often leveraged materials that inherently provided good insulation and airtight properties. Revisiting some of these materials could be beneficial.
3.4 Striking the Right Balance
For the forward-thinking homeowner, architect or builder, the key lies not in choosing between old and new but in harmoniously blending the strengths of both:
Informed Design Choices: Marrying the aesthetic appeal of modern designs with principles that enhance airtightness.
Quality Control: Ensuring that the workmanship standards are consistently high across all stages of construction.
Continuous Innovation: Integrating new technologies and materials that offer better airtightness solutions without compromising on design.
In conclusion, while the dichotomy between modern and older homes presents unique challenges, it also provides a rich tapestry of insights. Embracing the best of both worlds can lead to spaces that are not only visually compelling but also functionally superior in terms of airtightness.
Diagram showing Windtight and Airtight layers as well as thermal bridge free construction and super insulation
Chapter 4: Current Standards and Achievements
The realm of building and construction, particularly when it comes to airtightness, is a dynamic field. Regulations and standards are set to maintain a certain quality level and ensure energy efficiency. Yet, as the industry evolves, so does the challenge of consistently meeting these established standards. The Building Regulations 2022 is a testament to such an ambition, but how does it fare in practical scenarios?
4.1 An Overview of Building Regulations 2022
The Building Regulations 2022 is a cornerstone for construction standards in the UK:
Airtightness Standard: One of its regulations is the airtightness of buildings, setting the bar at 10 m3/hr/m2. This benchmark is founded on the principles of energy conservation, comfort, and sustainability.
Part L1A of the Building Regulations stipulates the baseline requirements for testing at a threshold value of 10m³/hr/m². However, the rate often required to achieve the TER is considerably lower.
In most designs, values ranging from 4 to 6m³/hr/m² are utilised. With meticulous attention to the details during the construction phase, these rates can be easily met. Once the construction is finalised, the actual air leakage rate is ascertained through on-site testing.
High-performance constructions, like Passivhaus homes, often consistently record rates lower than 1m³/hr/m².
All new homes must undergo testing upon completion, with two specific exceptions: 01: If an identical construction has been completed by the same builder within the previous year and has satisfactorily passed an airtightness test. 02: When a high default value of 15m³/hr/m² is applied in the SAP assessment.
If you wish to circumvent the uncertainty of on-site testing, an air leakage rate of 15 can be selected. This rate is akin to having a sizeable window left open during the test, thus eliminating the need for testing entirely. However, this would necessitate substantial countermeasures like extra-thick insulation amongst others.
4.2 Dissecting the Survey Findings
A survey targeting 100 contemporary homes brought some revealing insights:
Startling Figures: While standards project a certain level of airtightness, approximately 33% of these homes didn’t even achieve the set benchmark. Such a deviation is a cause for concern, indicating a potential disconnect between regulatory standards and on-ground execution.
Variability in Construction: Even within modern constructions, there was a vast variance in airtightness levels. While some exceeded the standards, others lagged woefully behind.
4.3 Impediments to Achieving the Standard
Several factors contribute to this noticeable disparity:
Knowledge Gap: Not all builders and contractors might be fully versed in the nuances of the airtightness standards, leading to unintentional oversights during construction.
Workmanship Consistency: As previously discussed, variability in workmanship quality can result in different airtightness levels.
Cost Factors: Achieving high levels of airtightness might involve additional costs in terms of materials and labour. Some builders might cut corners to stay within budgets.
The Complexity of Modern Designs: Advanced architectural designs can inadvertently introduce challenges in maintaining airtightness.
4.4 The Way Forward: Bridging the Gap
While the current scenario isn’t entirely bleak, there’s an evident need for course correction:
Awareness Campaigns: Construction industry stakeholders, including architects and builders, need periodic updates and training on the importance and techniques of achieving airtightness.
Robust Inspection Mechanisms: Regular and rigorous inspections during and after construction can help identify potential lapses and rectify them timely.
Feedback Loops: Learning from projects that failed to meet the standards can provide invaluable insights for future constructions.
Rethinking Standards: It might be beneficial to revisit the standards themselves periodically, ensuring they are in sync with current technologies, materials, and construction practices.
In summation, while standards like the Building Regulations 2022 provide a fairly solid foundation (but does need to be improved considerably due MVHR only being efficient when airtightness is below 7 m3/hr/m2), their real-world implementation demands continuous monitoring and adaptation. Only through concerted efforts from all industry stakeholders can the aspiration of optimal airtightness in every home be achieved and improved.
Airtightness test at our Red Brick House in Willesden, North West London
Chapter 5: Key Areas of Concern: Common Air Leakage Points
When aiming for optimal airtightness in buildings, it’s crucial to identify and address potential weak points where air leakages might occur. These weak points, often arising from various construction phases or oversight, can significantly compromise the energy efficiency of a structure. Our on-site experiences have illuminated some of the most recurrent areas of concern.
5.1 Gaps around Window Frames, Doors, and Floor Joists
The Issue: Improper sealing or alignment of windows and doors often leads to discernible gaps, while floor joists can sometimes be overlooked in terms of insulation and sealing.
The Solution: Utilising high-quality sealants, ensuring precise fittings, and opting for insulated frames can effectively mitigate these issues. Further, insulation between floor joists can restrict air flow and enhance thermal efficiency.
5.2 Hollow Sections in Suspended Floors or Walls
The Issue: These sections can act as conduits for unwanted airflow due to cavities created during construction or as a design feature.
The Solution: Proper insulation within these hollow sections or using solid construction techniques can reduce or eliminate such air pathways.
5.3 Cracks in Masonry or Gaps Behind Plasterboards
The Issue: Natural settling of buildings or subpar masonry can result in cracks. Similarly, improperly installed plasterboards can leave air pockets.
The Solution: Regular building inspections can help identify these issues early on. Filling cracks with appropriate sealants or mortar and ensuring flush plasterboard installations can address these concerns.
5.4 Areas Around Pipes, Vents, Heating Systems, and Electrical Fixtures
The Issue: These installations often require openings in walls, floors, or ceilings. If not sealed correctly, they can become significant sources of air leakages.
The Solution: Using gaskets, sealants, or specially designed collars around these installations can ensure a tight fit and minimise air infiltration.
5.5 The Imperative of Meticulous Inspection
Ensuring airtightness is not merely about addressing the obvious points of leakage but also about conducting thorough and regular inspections:
Proactive Identification: Regular inspections, especially post-construction and during maintenance phases, can spot potential problem areas before they escalate.
Leveraging Technology: Tools like thermal imaging cameras can visually pinpoint areas of air leakage, making the task of sealing and repair more targeted.
Skilled Professionals: Engaging professionals with expertise in building diagnostics can lead to more accurate identification of leakage points and suitable solutions.
In summary, while contemporary construction offers numerous advantages, it also brings its own set of challenges. By understanding and addressing common air leakage points, we can significantly improve the energy efficiency and comfort levels of a building. Meticulous inspection, combined with preventive and corrective measures, ensures that our structures stand the test of time and utility.
Airtightness Test at Red Brick House, North London, showing the blower door test being set up
Chapter 6: The Airtightness Barrier: An Architect’s Tool
The airtightness barrier often likened to an invisible shield, plays a pivotal role in modern architectural design. Its essence lies in ensuring that a structure remains as impervious to unwanted air infiltration and exfiltration as possible, preserving energy efficiency and promoting a comfortable interior environment. But what is this barrier, and how can architects integrate it seamlessly into their designs?
6.1 Understanding the Airtightness Barrier
Definition: The airtightness barrier isn’t just a single layer or component. Instead, it’s a holistic system, encompassing a variety of materials and techniques, all working in unison to prevent unwanted airflow. This might include membranes, tapes, sealants, and gaskets.
Functionality: Beyond just preventing air leakage, this barrier also ensures the controlled exchange of air. This means that while uncontrolled air leakage is minimised, ventilation systems can operate more efficiently, ensuring good indoor air quality.
6.2 Integration at the Design Stage
Holistic Approach: Rather than being an afterthought, the airtightness barrier must be integrated right from the conceptual stage of design. This ensures that the barrier complements structural and aesthetic elements rather than hindering them.
Flexible Solutions: Depending on the building type, purpose, and location, the specifics of the barrier can vary. Thus, architects need to tailor the barrier to each project’s unique needs.
6.3 Key Considerations for Architects
Material Selection: Architects should opt for durable and resilient materials for the barrier, considering the local climate, potential exposure conditions, and desired lifespan of the structure.
Seamless Transitions: Where different materials or building components meet, there’s a heightened risk for air leakage. Architects should design in such a way that these transitions are meticulously sealed and guarded against potential breakages.
Incorporating Ventilation: While the objective is to minimise uncontrolled air leakage, architects must also plan for controlled ventilation, like Mechanical Ventilation Heat Recovery (MVHR). This ensures fresh air exchange without compromising the efficiency of the barrier.
6.4 Future Innovations and Adaptations
Technology-Driven Solutions: As building technology evolves, architects can leverage advanced tools and software to simulate and test the efficacy of their airtightness barrier designs.
Continuous Learning and Upgradation: The world of architecture is in perpetual evolution. By staying attuned to emerging best practices and novel materials, architects can continually refine their approach to airtightness.
In conclusion, the airtightness barrier is an indispensable tool in the architect’s arsenal. It not only upholds the energy efficiency and comfort of a building but also accentuates the importance of forward-thinking, sustainable design. By weaving this barrier seamlessly into the fabric of their designs, architects are able to create structures that stand as testimonies to both form and function.
Visible smoke used during the Blower Door test to detect leakages in the building fabric
Chapter 7: Developing an Airtightness Strategy: From the Drawing Board to the Site
The art of crafting a building that stands against the onslaught of uncontrolled airflow is no mean feat. An airtight building is not just about integrating specific materials but encapsulating a vision that spans from initial sketches to the very last brick. The journey is intricate, demanding a blend of foresight, strategy, and concerted teamwork.
7.1 Setting Clear Performance Targets
Benchmarks and Metrics: Every successful airtightness strategy commences with well-defined targets. By stipulating specific air leakage rates or other measurable benchmarks, the project sets clear expectations from the outset.
Adherence to Regulations: While setting targets, it’s imperative to align with existing building regulations and guidelines, ensuring that the building not only meets but exceeds industry standards.
7.2 Leveraging Performance-based Specifications
Material and Component Selection: Using performance-based specifications means that materials and components are chosen based on their ability to meet the desired performance criteria, rather than just their inherent characteristics.
Continuous Assessment: Regular performance evaluations during construction ensure that the project remains on track and that any discrepancies can be addressed promptly.
7.3 Ensuring Stakeholder Alignment
Workshops and Training: It’s pivotal that everyone involved, from masons to electricians, is on the same page. Hosting workshops or training sessions can help familiarising teams with the airtightness strategy.
Regular Communication: Open lines of communication between teams can facilitate the identification and resolution of potential airtightness challenges. Frequent meetings, updates, and feedback sessions can prove beneficial.
7.4 The Role of the ‘Airtightness Champion’
Duties and Responsibilities: The Airtightness Champion is not just a title. This person is tasked with overseeing the entirety of the airtightness strategy, from monitoring material procurement to ensuring quality control on-site.
Bridging the Design-Construction Gap: One of the pivotal roles of the Airtightness Champion is to ensure a seamless transition of the airtightness vision from design to construction, eliminating ambiguities or misinterpretations.
Advocacy and Awareness: This champion also plays an educational role, advocating for best practices, introducing new techniques, and ensuring all members understand the importance of airtightness.
7.5 Iterative Refinement and Feedback
Post-Construction Analysis: Once a project is completed, a thorough analysis can provide insights into what worked and areas of improvement. This feedback can then inform future projects.
Incorporating Technological Tools: Tools such as blower door tests or thermal imaging can offer real-time data during construction, facilitating adjustments in the airtightness strategy as needed.
In summary, creating an airtight building is a symphony of precise strategy, unwavering focus, and harmonious teamwork. It’s about setting clear visions, arming oneself with the right tools, and ensuring every hand that touches the project does so with airtightness in mind. With such a holistic approach, the resulting structures not only stand firm against air leakages but also serve as benchmarks for others to emulate.
Blower Door Test being set up at our Red Brick House in Willesden, North West London
Chapter 8: Practical Steps to Achieving Airtightness
Airtightness is as much about tangible measures as it is about theory. Successful integration of airtightness in a building requires attention to detail, a deep understanding of materials, and rigorous processes. Here, we delve into some of the hands-on steps we’ve employed to translate our airtightness strategy into concrete outcomes.
8.1 The Imperative of Air Barriers
Characteristics of Ideal Barriers: The crux of airtightness lies in choosing barriers that are impermeable to airflow, continuous across junctions, and durable over time. Whether it’s a vapour barrier or a more rigid material, ensuring its continuity is essential to prevent leakages.
Positioning and Installation: Air barriers must be placed in areas where they won’t be compromised by subsequent building processes or later modifications.
8.2 Sealing Laps in Membranes
Material Selection: Specialised tapes and adhesives are imperative for ensuring the tightness of joins in air barrier membranes. Opting for high-quality materials that adhere well and remain effective over time is vital.
Technique: Correct lapping, typically overlapping the upper layer over the lower one, ensures that any water moving downwards doesn’t penetrate the barrier.
8.3 Window, Door, and Fixture Sealing
High-Quality Sealants: Using premium-grade sealants, which offer long-lasting protection against the elements, is paramount.
Attention to Detail: This involves not just the external perimeter but also areas like window and door sills, which can often be overlooked. Ensuring full perimeter sealing can drastically reduce air leakage.
Insulation: Beyond sealing, effective insulation of these openings, using products like expanding foam, can further enhance airtightness, but care must be taken when using expanding foam as studies have found that the foam can degrade over time creating air leakages.
8.4 Addressing Services in External Walls and Floors
Seal Service Penetrations: All service conduits, whether for electricity, water, or gas, must be meticulously sealed at the point they penetrate external barriers. This can be achieved using collars, grommets, or specific sealants.
Regular Inspection: Over time, seals can degrade or become compromised. Regular inspections can ensure any wear and tear is promptly addressed.
8.5 Airtight Light Fittings and Redundancy Measures
Lighting Considerations: Opting for airtight light fixtures ensures that the integrity of ceilings isn’t compromised. Where traditional fittings are used, additional sealing measures might be needed.
Unused Areas: Features like unused fireplaces can become significant sources of air leakage. Installing chimney balloons or draught-proofing measures can effectively block these off.
In conclusion, achieving airtightness is a meticulous process, requiring a blend of the right materials, expert techniques, and regular quality checks. By committing to these practical steps, we bring the theory of airtightness to life, crafting structures that are not only energy-efficient but also resilient against the elements.
Chapter 9: The Crucial Role of Testing in Airtightness
Achieving airtightness is not a matter of mere assumption or theory. It’s a tangible quality, measurable and quantifiable, and this is where testing comes into play. Comprehensive testing serves as a confirmation of our design and construction practices and provides invaluable insights into potential improvements.
9.1 The Essence of Air Testing
Objective Measurement: Airtightness tests offer a quantitative assessment, translating the efficacy of our strategies into measurable metrics. This allows us to assess if we have met or exceeded the set airtightness standards.
Timely Detection: By integrating testing at various stages of construction, from the initial phases to the final touches, we can swiftly pinpoint and rectify areas that aren’t meeting the desired standards.
9.2 Techniques and Tools: From Smoke Sticks to Pressure Tests
Smoke Sticks: A basic yet highly effective technique, smoke sticks or pencils emit visible smoke that gets drawn towards areas of air ingress. This not only visually demonstrates the leakage points but also offers an immediate way to gauge the severity of the issue.
Blower Door Test: This is a more comprehensive technique, involving the use of a powerful fan to depressurise the building. By measuring the rate at which air flows into the structure to equalise the pressure, this test provides an accurate measure of the building’s overall airtightness.
Thermal Imaging: Infrared cameras can detect differences in temperature caused by air leakages. This visual method is particularly useful in large structures or in conditions where other methods might be less effective.
9.3 Proactive Addressing of Issues
Immediate Rectifications: Once a leakage point is detected, immediate steps can be taken to address the issue. This might involve additional sealing, repairs, or even redesigning certain components.
Iterative Testing: After making necessary modifications, the area or the building can be re-tested to ensure that the remediation has been effective.
9.4 The Broader Impact of Testing
Ensuring Compliance: Regular testing ensures that our buildings are compliant with the latest regulatory standards, protecting stakeholders from potential legal implications and ensuring the building’s occupants reap the full benefits of an airtight structure.
Building Confidence: Regular testing instils confidence in both our team and our clients. It demonstrates our commitment to quality, precision, and energy efficiency.
It’s evident that testing is not just a regulatory necessity but an architect’s ally. It offers a clear pathway, turning the abstract concept of airtightness into a concrete achievement. With each test, we come closer to perfecting our understanding of the intricate dance between design, materials, and construction in creating airtight buildings.
Chapter 10: Airtightness Standards: An Overview
Navigating the realm of architectural design and construction without a thorough understanding of prevailing airtightness standards is akin to sailing without a compass. These standards, often instituted by reputed bodies and research organisations, form the foundation for modern sustainable building practices.
10.1 The Evolution of Airtightness Standards
Historical Context: The recognition of the importance of airtightness is not a recent phenomenon. Over the decades, as our understanding of energy efficiency grew, so did the push for more stringent standards. Initially focused on mere conservation, today’s standards strive for holistic sustainability.
Current Trends: As technology and construction methodologies advance, so do the benchmarks. Today, the push is not just for airtightness but also ensuring that buildings have effective ventilation, striking a balance between energy conservation and indoor air quality.
10.2 Key Organisations and Their Contributions
British Standards Institute (BSI): As the national standards body of the UK, the BSI plays a pivotal role in formulating airtightness standards. Their guidelines are comprehensive, covering aspects from material selection to construction techniques, and serve as a reference point for many professionals in the industry.
Building Research Establishment (BRE): BRE, with its extensive research and consultancy in the built environment, provides invaluable insights and recommendations. Their studies often inform the evolution of standards, ensuring they are rooted in empirical evidence and practical experience.
10.3 Interpreting the Standards: Beyond the Jargon
Quantitative Benchmarks: Most standards provide specific numerical values that buildings should adhere to. These might pertain to the permissible air leakage rates, insulation levels, or the efficacy of ventilation systems.
Qualitative Guidelines: Apart from numbers, standards often offer qualitative advice, covering best practices, potential pitfalls, and recommendations for various construction scenarios.
Case Studies and Examples: Many standards, especially those by research bodies like BRE, also provide real-world case studies. These examples offer a practical perspective, illustrating how the standards translate in real-world scenarios.
10.4 The Global Perspective
International Standards: While the UK has its unique standards, it’s crucial to be aware of international benchmarks, especially when working on projects with global stakeholders or in different countries. Organisations like the International Organisation for Standardisation (ISO) provide guidelines that often influence or align with national standards.
Adapting to Local Context: While standards provide a general framework, each building project has its unique context. It’s essential to adapt these guidelines considering local conditions, materials available, and specific project requirements.
In summary, while airtightness standards can initially seem overwhelming, they are invaluable tools in the architect’s arsenal. By staying updated, understanding the rationale behind these standards, and applying them judiciously, architects and builders can ensure that their creations are not just aesthetically pleasing but also environmentally responsible and sustainable.
Some popular airtightness membranes include: 01 Pro Clima Intello I 02 Ampatex / 03 Isover Vario / 04 Medite Smartply ProPassiv airtight OSB / 05 Blowerproof liquid airtight paint / 06 Airstop Diva Forte. Image credit: Passivehouse Plus
Conclusion: Airtightness – The Architectural Keystone of Tomorrow
In the vast expanse of architectural elements, airtightness, once perhaps seen as a mere footnote, has steadily grown in stature. The burgeoning focus on sustainability, climate change mitigation, and the inexorable drive for energy efficiency, has placed airtightness at the very heart of contemporary building design and construction.
The Holistic Impact of Airtightness Airtightness isn’t an isolated discipline; it has a domino effect. Enhanced airtightness in buildings not only conserves energy but also elevates indoor air quality, reduces energy bills, and diminishes the carbon footprint of the structure. It’s a singular solution with multifaceted benefits.
Adapting to a Changing Climate The global climate crisis mandates swift and effective responses. Buildings, as significant consumers of energy, play a colossal role in either exacerbating or alleviating this crisis. Airtightness is one of the primary solutions within our grasp that can help transform the energy profile of our structures, making them more resilient and less demanding on our planet’s finite resources.
The Cultural Shift in Architectural Design Beyond the hard metrics of energy savings and carbon reduction, there’s a cultural evolution at play. Homeowners, builders, and stakeholders are increasingly educated about the virtues of airtight design. As this cultural shift continues, architects and designers are in a prime position to lead the narrative, ensuring that airtightness isn’t just a technical specification but a central ethos.
The Road Ahead There will undoubtedly be challenges. New materials, evolving technologies, and ever-changing regulations will keep the architectural and construction industries on their toes. But with challenge comes opportunity. The commitment to airtightness represents an opportunity to reimagine the buildings of tomorrow, creating structures that are harmonious with their environment, efficient in their function, and exemplary in their design.
In the final analysis, airtightness is more than a technical requisite; it’s a testament to our collective responsibility. It’s about crafting buildings that don’t just stand as monuments to our creativity but as symbols of our commitment to a sustainable future. As we stand on the precipice of architectural evolution, addressing airtightness isn’t just a choice – it’s an imperative for the generations to come.
If you would like to talk through your project with the team, please do get in touch at mail@risedesignstudio.co.uk or give us a call on 020 3290 1003
We have been involved in exploring the new frontiers of low-energy and low-embodied carbon designs for many years. Today, I’m excited to share the crucial role architects, like us, have in fighting the biggest challenge of our age – the climate crisis.
Chapter 1: The Imperative of Carbon-Conscious Building
Constructing the buildings that define our skylines and streets generates a staggering 39% of global carbon emissions. These emissions include “embodied carbon” from the manufacture and transport of building materials, and the “operational energy” used in running the buildings. The goal, therefore, is to aim for “net zero emissions” – a balance between the carbon emissions produced and the carbon sequestered or offset by renewable energy sources. But to truly confront climate change, we must strive beyond neutrality towards carbon-positive buildings – structures that go a step further to remove more carbon from the atmosphere than they emit.
McKelvey Farm House, an example of carbon positive design
Chapter 2: The Carbon-Positive Paradigm
By producing more energy than they consume, carbon-positive homes raise the bar for sustainable living. They embody a compelling blend of benefits including economic gains, environmental improvements, and health advantages for their inhabitants. Achieving such architectural marvels involves careful choice of low embodied carbon materials and designing the building to create an energy surplus during operation.
Chapter 3: Demystifying Embodied Carbon
Creating carbon-positive structures starts with the selection of sustainable building materials. These materials reduce embodied carbon – the sum total of greenhouse gas emissions produced during their manufacture, transport, and installation. Remarkably, some building materials even sequester carbon, trapping it within the building for its lifespan. Materials like bamboo, cork, straw, hempcrete, cellulose fibre, and wool insulation, alongside timber sourced from sustainably managed forests. Prefabricated construction methods also play a crucial role in minimising waste, further reducing embodied carbon.
Chapter 4: The Power of Energy Efficiency
Nearly half of a home’s energy usage goes to heating and cooling. Implementing passive solar design – features that maximise natural heating and cooling – is therefore essential to reducing energy consumption. From building orientation and external shading to airtight envelopes, insulation, and energy-efficient windows, each element plays a part in reducing the need for mechanical heating and cooling. Green features such as green roofs and green walls, LED lighting, and passive heat transfer also contribute significantly to maintaining indoor comfort while reducing energy use.
Chapter 5: Harnessing Renewable Energy
Once a home’s energy consumption is optimised, it’s time to generate carbon-free power. Methods for doing this vary by location and include solar panels, wind turbines, and Ground Source Heat Pumps. It’s also worth noting that the grid itself is becoming greener. With ambitious targets for all electricity to come from 100% zero-carbon generation by 2035, the UK government is setting the stage for a more sustainable future.
Chapter 6: Certifications and Regulations to Ensure Sustainability
A plethora of building regulations and certifications exist to recognise sustainable and resilient design. Standards such as BREEAM Outstanding, the International Living Future Institute’s Zero Carbon Certification, and Powerhouse set benchmarks for sustainability. These rigorous certifications not only focus on operational energy usage but also consider energy inputs associated with construction and materials used.
The Zeb House, in Norway, is proof that carbon positivity can be achieved in even the coldest of climates
Beyond meeting regulations, architects and developers around the world are pushing boundaries to design and build carbon-positive structures. ArchiBlox, an Australian-based architectural practice, has designed the first-ever carbon-positive prefab home, demonstrating that low-carbon design can be affordable, efficient and aesthetically pleasing. Similarly, the ZEB Pilot House in Norway shows how a small home can generate enough surplus energy to power an electric vehicle year-round.
Chapter 8: The Tah.Mah.Lah Project: A Living Example
Tah.Mah.Lah, a pioneering residential project in California, offers an early example of how homes can go beyond carbon neutrality. This environmentally regenerative home produces more energy than it consumes, restores native habitats, recycles water, and reduces waste. It serves as a beacon of inspiration, showing us how innovative design can lead to carbon-negative homes.
Chapter 9: A Future Vision: The Architecture of Tomorrow
Our focus on low energy and low embodied carbon designs reflects our commitment to the future of our planet. By harnessing sustainable materials, incorporating energy-efficient design principles, and using renewable energy, we can create homes that not only tread lightly on our Earth but actively contribute to healing it.
Chapter 10: Joining the Low-Carbon Revolution
The urgency of climate change requires us all to play a part in creating a sustainable future. As architects, we have the privilege and responsibility to lead the way in this low-carbon revolution. Whether you’re a homeowner looking to retrofit your existing property or a developer aiming to create the next carbon-positive building, we invite you to join us in this exciting journey towards sustainable living.
In conclusion, carbon-conscious building isn’t just a trend – it’s a necessary shift towards a sustainable future. Let’s build not just for our generation, but for those to come. Together, we can shape a world where buildings are part of the solution to our climate crisis, rather than a contributing factor.
If you would like to talk through your project with the team, please do get in touch at mail@risedesignstudio.co.uk or give us a call on 020 3290 1003
