Holy Trinity Tulse Hill are proud to be named as finalists in the sustainability and community engagement sections of the National Building and Construction Awards.
Here at Holy Trinity we’re self-building the first straw-bale church building in Europe, and one of just a handful globally.
It’s also the largest urban community self-build in Europe or straw construction. To put that another way, you could fit a row of seven houses into our footprint.
So what are the green credentials of a straw-bale building?
Every building releases carbon dioxide and other greenhouse gases during the process of construction through the manufacture of materials, transportation to site, use of plant and machinery on site and so on. A building of our size, conventionally built, would be expected to release 400 tonnes. The CO2 release of our build is just 10% of that figure, at 40 tonnes. But there’s more…
Materials such as concrete, steel, and glass – the staples of buildings all over London – release huge amounts of gas in their manufacture. But materials such as timber and straw actually capture CO2 during their breathing lifetime, and therefore lock it up once they are cut down.
Through cutting and hand-constructing our huge timber frame on site, and by using straw-bales for the walls, we’ve actually captured 120 tonnes C02. By avoidance of concrete in our foundations and render, we’ve saved a further 28 tonnes.
And because we’ve covered the whole of our South-Facing roof with efficient solar PV, we’re going to save a further 331 tonnes over the nominal lifetime of the building. (By the way, a nominal lifetime is 60 years, but our building will last up to 200 years!)
So while a conventional building of our size would be expected to release 400 tonnes CO2, ours is actually saving more than that amount: 479 tonnes carbon negative.
Valuable Clay – Flexible Walls
The 500m2 of our internal walls is plastered with clay dug up from our own foundations and processed by hand on site. London clay is a headache for architects, builders, developers and occupiers alike because it expands and contracts with the weather and can cause subsidence. For us, London clay has been a valuable resource.
Our hand-built tyre foundations were independently tested on site and showed themselves to withstand up to 100 tonnes per square metre. 465 scrap tyres have been saved from landfill in the process.
Since 2017 we’ve had over 500 volunteers working on site. They include primary school classes, people in their 80s, a building club from the local girls’ secondary, members of our church and community, people travelling from Truro in the South West and Newcastle in the North East Community Payback and Young Offenders, people with learning difficulties, and trades students from South Thames colleges, and clay plaster experts from all over Europe.
Like much of inner South London, Tulse Hill is a place where many young people are vulnerable. So it’s fantastic to be able to build into their lives with this new and different opportunity. They can actually use their hands to make a difference. Or as one thirteen-year-old girl said, “I want to walk past this church with my grandchildren and say, “I built that.”” Now that’s what I call thinking ahead!