Passive House – a luxurious way to take climate action

 

At RISE Design Studio, we work hard to minimise the environmental impact and energy consumption of our projects. One way we do this is by working with the Passive House and EnerPHit standards. In October 2021, publisher and editor of Passive House Plus magazine, Jeff Colley, gave a TEdx talk in Tralee on ‘How Passive Houses can improve your life and help the planet’. Jeff’s talk highlighted some of the key reasons why the Passive House is key to tackling the climate emergency.

Passive House RISE Design Stdio

What is a Passive House?

A Passive House (or Passivhaus) tends to use energy sources from within the building, such as body heat, heat from the sun or light bulbs, or heat from indoor appliances to create a comfortable, healthy living environment. Typically, a Passive House features high levels of insulation to roofs, external walls, ground floors (with no heat loss at junctions), triple glazing and air tightness. A ventilation system recovers heat from stale outbound air and passes it onto incoming fresh air that is then filtered when entering the house.

Your home is your sanctuary

In an increasingly uncertain world, we are often made to feel that taking climate action equates with making sacrifices in our lives. However, the Passive House shows us how climate action does not need to feel like this. Instead, it can improve life in several ways. Most importantly, a Passive House costs very little to heat (and in some cases nothing at all), and the internal environment always feel fresh and comfortable, whatever the weather.

The emphasis on ‘future proofing’ means that a Passive House can withstand any weather and/or temperatures that the future may bring. As Jeff Colley explains in his talk, people who live in Passive Houses regularly describe constant comfort, no ‘cursing at the cold’ in the mornings, and peace and quiet – acoustic performance is very high, making it hard to hear anything outside or between party walls in flats/other shared accommodation.

No need for heating

Impressively, there are many examples of Passive Houses whose residents rarely or never turn on the heating system. In some houses, a heating system is not even needed, with only small battery-powered back-up if required. For example, of 18 sheltered housing units built in Devon for elderly people, the heating had not been turned on in nine of the units five years after construction. Similar accounts relate to Passive Houses in which there has been a boiler issue but this is not an urgent problem, as in more standard homes.

A healthy home is a happy home

In the west, we spend about 90% of our time in our buildings, making it important that our home is a healthy place to be. Experiences during the pandemic have also made us think more about air quality and ventilation. Recent research in Ireland suggests that the benefits of Passive Houses go even further than reducing energy use and creating a comfortable living environment. Over 200,000 global lung cancer deaths each year are estimated to be caused by the presence of radon in buildings. This is a particular issue when the weather is cold outside and the indoor environment is warm – radon can rise up from the ground into the living environment. The average levels of radon in a Passive House have been found to be much lower than in an average home.

Drawbacks?

Some critics have questioned whether the Passive House standard restricts architectural freedom. However, the standard is remarkably flexible and accommodates good design, in both retrofit and new build projects. The standard can be applied to any building, including commercial and residential, and even listed period buildings.

The first Passive House hospital is nearing completion in Frankfurt and Passive House schools are becoming increasingly common, such as the Harris Academy in Sutton. Impressively, the standard has also been used in a very progressive council housing scheme in Norwich. The standard can be used to create a good indoor environment for ‘things’ rather than people as well. For example, an Imperial War Museum archive near Cambridge uses the approach to protect its artefacts for future generations.

Jeff Colley suggested that the main drawback of living in a Passive House is that it may become hard to stay in other people’s homes when one has become so accustomed to such high comfort levels. Joking aside, the Passive House is an excellent example of how ‘being green’ doesn’t have to mean sacrifice. As Jeff argues, it is one form of radical climate action that everybody can agree to. We fully support this argument and we continue to work with clients on new build and retrofit projects that apply the Passive House and/or EnerPHit standard.

Photo: Hervé Abbadie and Karawitz

Refurbishing homes for net zero – upskilling our design team

 

Refurbishing and retrofitting existing homes is a large part of the challenge of transitioning the built environment to net zero. We are faced with a significant task, especially as every home is different – efficiency measures that work in one home may not be appropriate for another. Retrofitting is also a daunting task for homeowners, particularly in terms of engaging a contractor with the right skills and experience for the job. At RISE Design Studio, we have worked on several projects that have included energy efficiency measures and, as the push to net zero becomes ever more critical, we are working hard to upskill our design team so all our projects are as energy efficient as possible.

Retrofit flat London

Embracing refurbishment

The 2008 Climate Change Act committed the UK to reducing its greenhouse gas emissions by 80% by 2050. The buildings sector accounts for 37% of total UK GHG emissions and, of these emissions, 65% are from the residential sector. As a result, there has been growth in the residential retrofit industry, with buildings being adapted to be more sustainable and energy-efficient. The majority of our existing residential stock requires some level of retrofit to enable the government’s ambitious emissions targets to be reached.

Common measures include improving insulation. A new heating system might also be installed, or double glazing might be fitted. Yet, conserving energy is not the only reason to retrofit a building. Improving indoor environmental quality, reducing dampness and mould will all lead to increased health and productivity levels of residents.

Upskilling our design team

Recognising the increased momentum in London around reaching net zero, we have really enjoyed working with clients on refurbishment projects that incorporate environmental considerations. Modern architects are well-placed to add creativity and innovation into the drive to retrofit existing housing stock, particularly those that may prove very expensive to retrofit. For example, historic buildings such as Edwardian terraces are protected, and increasing energy efficiency can pose a real challenge. However, there are exciting options to retain the façade and rebuild the living spaces within the building.

More and more clients are seeking energy efficient homes and we are fully aware of the important role architects play in helping to reach the government target for 2050. As a result, we have been working hard to upskill our design team to work on these types of projects.

Maximising design benefit

There are several industry standards designed to increase the efficiency of residential property, including the Passivhaus and EnerPhit certifications. A Passivhaus project tends to use energy sources from within the building, such as body heat, heat from the sun or light bulbs, or heat from indoor appliances to create a comfortable, healthy living environment. However, it can be difficult to reach the exact requirements of the Passivhaus standard in a retrofit project.

Recognising this, the Passivhaus Institut has developed the EnerPHit standard for projects that use the Passivhaus method to reduce fuel bills and heating demand. We are working hard to implement this standard in our projects and our design team has developed the skills to align retrofit projects with this approach. EnerPHit takes into account the limitations associated with retrofit projects and relaxes some of the Passivhaus criteria to reflect this. Nevertheless, it is still a very demanding standard and generally results in a building that outperforms a new-build property both in terms of energy and comfort.