Working towards a Net Zero London

 

Earlier this month, New London Architecture (NLA) published a report on ‘Zero Carbon London‘. Part of NLA’s Net Zero programme (#NLANetZero), the report provides new insight into progress in the built environment profession in the fight against climate change. It is based on results of a survey of over 100 London-based companies in the sector and points out some of the biggest challenges and opportunities for the city to get to Net Zero. In this post, we pull out some of the key points that ring particularly true for our firm.

Net Zero London RISE Design Studio

What is Net Zero London?

‘Net zero carbon’ is often used as a proxy for the six greenhouse gases: carbon dioxide is the most common of these. ‘Net’ refers to the sum of carbon emissions and carbon offsetting/sequestration (e.g. via absorption of carbon dioxide because of new woodland creation) being equal to zero. It is now widely-proven that climate change is caused by the increased concentration of greenhouse gases emitted in the atmosphere from human activities. This leads to an increase in global temperatures (global warming). Reducing the emissions of man-made greenhouse gases is therefore vital for tackling the climate emergency, and this is why ‘net zero carbon’ is so important.

For cities, which account for over 70% of global emissions and consume over two thirds of the world’s energy, reaching net zero is urgent. London has been one of the first global cities to commit to becoming carbon neutral by 2050 – the Greater London Authority has a plan to achieve this ambitious aim. 27 of the 32 London Boroughs and City of London have so far declared a climate emergency. London is also one of the major global cities that has signed the C40 Net Zero Carbon Buildings Declaration, committing to ensure that all new buildings operate at net zero carbon by 2030 (and all existing buildings at net zero carbon by 2050).

Achieving net zero in construction

The UK Green Building Council (UKGBC) explains net zero in construction as ‘when the amount of carbon emissions associated with a building’s product and construction stages up to practical completion is zero or negative, through the use of offsets or the net export of on-site renewable energy’. A net zero carbon building tends to be highly energy efficient and powered from on- or off-site renewable sources, with any remaining carbon balance offset.

There are plenty of exciting initiatives and projects being undertaken by public authorities and the private sector: from a citizens’ assembly facilitated by Camden Council to come up with recommendations for zero carbon homes, to the RIBA 2030 Climate Challenge that sets out the actions that chartered practice like RISE Design Studio will need to take.

More to be done

The NLA survey highlighted good progress in the sector. First, the vast majority of those who took part have signed up to one of the industry pledges such as Architects Declare (we have signed up). Second, those in the industry generally feel that they have the skills to address climate issues.

However, those who completed the survey feel that the biggest barriers to positive change are regulation and finance. The lack of green finance is a critical barrier for the London Boroughs to implement and achieve their targets. For organisations like ours, the current policy frameworks are not effective and act as a barrier for implementing measures that will get us to net zero. For example, a recent government consultation on banning the use of combustible materials in buildings suggests that a lack of joined-up thinking remains an issue – timber plays a very important role in decarbonsing construction.

The Covid-19 lockdown between March and May 2020 demonstrated that it is possible to reduce emissions and address behaviour change in a short time – carbon emissions in London dropped by 60%. But, the challenge is to achieve this reduction at the same time as people living their lives freely.

There is strong optimism in the sector that there is now an opportunity to transform our way of life and act in a more environmentally-conscious way. The upcoming inauguration of a US President who ran on a manifesto of clean energy and net zero no later than 2050 is also encouraging, particularly if he manages to rally the rest of the world (and our Prime Minister) to take the same steps.

Exploring Chailey Brick Factory

 

We recently attended a CPD tour organised by RIBA to the Ibstock brick factory in Chailey, near Lewes in Sussex. It was fascinating to see process of traditional stock brick manufacturing in one of the last remaining clamp-firing factories in Europe. We highly recommend a trip to the factory if you’re looking to source traditional stock bricks. This short post tells you a bit more about what we learned on our visit.

chailey-bricks

History

Clay products have been manufactured in Chailey for over 300 years, making it one of the oldest factories still in production in the UK. Its product range has changed over time and it now produces high quality, clamp-fired stock bricks and pavers with a range of colours and textures which give a unique charm. Bricks are known for being made in Chailey since the early 17th century. The current factory was built in 1946 in order to take advantage of modern production processes and the post-war building boom. The current owner, Ibstock Brick, acquired the site in 1996.

Making the bricks

At Chailey, weald clay is extracted from an onsite quarry behind the factory during the summer months. There are three different seams of clay in the quarry, all with different drying and firing characteristics. Clay is dug from a stockpile each day and fed into the factory, delivering a set amount of clay each hour. Clay is mixed with sand and pulverised fly ash, which help with the drying process, and with a blend of coke breezes, which is the fuel that fires the bricks. All the material is fed into a wet pan, where it is mixed and ground together and water is added. The material is forced through grids in the floor of the wet pan and onto a conveyor, after which it falls between two counter-rotating drums, with a gap of only 3mm between them. This is so that a small but consistent grade size is achieved.

The material is then mixed in a double-shafted mixer where two shafts churn the mix to ensure and smooth and workable consistency. The mix is then taken to a kettle where it is stored before being turned into bricks in a molding machine which is capable of making 12,000 bricks per hour. The excess clay is struck off before a palette is dropped onto the bottom of the bricks. Bricks are piled in stillages which are then put into the driers, where the bricks are dried over a 23 hour period. There are five dryers and each one holds 24,192 bricks. The temperature in the driers is slowly increased up to 110 degrees and approximately 17 tonnes of water is removed from the bricks.

The clamp

A clamp is ‘a carefully constructed stack of bricks’ in a large shed similar to a cowshed. Before going to the clamp, the dried bricks are inspected for defects and stacked into piles of 780 bricks (weighing 1.8 tonnes). These bricks are then laid on the floor of the clamp by hand by a setting team. Fire holes are built into the clamp before all the bricks are laid on top and the clamp is then covered in refractory insulation bricks and casing bricks which help to insulate the clamp during the firing process. Each clamp holds between 750,000 and 800,000 bricks and takes three weeks to build.

brick-clamp

Gas burners are used to ignite the fuel which was mixed into the body of the bricks during the clay preparation process. The bricks fire at over 1000 degrees centigrade and only start to cool down when all of the fuel has burnt out. The entire firing cycle takes three weeks. When the bricks have cooled sufficiently, the bricks are packed up by hand onto pallets by an eight man team. There is a strict sorting code and the bricks are sorted according to their quality and colour and then hand sorted into packs of 370 bricks. It takes approximately two weeks for the team to pack up a clamp.

clamp-full

The bricks

Chailey manufactures its range of distinctive bricks in both 65mm and 50 mm sizes and any of the bricks can be blended to create products to match up to existing brick work. Or, bespoke blends of bricks can be created. You can read more about the bricks made at Chailey on the Ibstock Brick website.