Installed Measures:
Personal Story:
When I was in my twenties, I worked out in Africa doing low cost self-build housing, which helped to inform my political outlook on the world. Coming back, I became aware that development issues and global issues were linked not so much to policies out in Africa but to a lack of understanding back in the West. And it seemed to me at the time – I’m talking about the eighties – that green issues, which were often regarded as fringe issues then, were in fact very central issues to a global outlook. So those issues have been very important to me since, and my architectural thesis looked particularly at energy and green building issues. I’ve been very interested in green issues throughout my years in architectural practice, and in this zero carbon house we’ve been able, as combined architect and client, to take them even further.
Motivations:
As a growing family we were looking around at first for a site to build a new zero carbon house. However, there were no vacant sites because the locality we’re in is very dense urban housing. It very quickly became apparent that it would be much more interesting to take an existing house and attempt to retrofit it, to the very demanding Code for Sustainable Homes Level 6 zero carbon level, than it would be to build a new house. Once I had embraced that idea, and saw that in fact it had much wider sustainability potential and implications as there are many more old houses than new ones, each using much more energy, I became very interested in how we could pursue it.
Property:
This semi detached property built in the 1840s has been substantially extended and converted from the original 2 bedroom house to a 4 bedroom house with a studio loft. Completed in 2009, the UK’s first retrofit house to “zero carbon” standard (Code for Sustainable Homes level 6). It generates all its own renewable energy with no use of fossil fuels, and has won six design awards including Civic Trust Commendation and RIBA Architecture Award. This is a private family home.
“quirky, delightful…a thoughtful design of exceptional quality” – RIBA
“I’ve seen the future – and it’s in Birmingham” – The Times.
Designing Zero Carbon Buildings Using Dynamic Simulation Methods by Ljubomir Jankovic (Routledge, 2012), features this house as an extended 22 page case study. It also features in a BBC TV Inside Out episode.
Measures:
As part of the substantial extension made to the original property, we installed certain measures to get the house to zero carbon. Insulation is a key factor in reducing heat loss; therefore we installed it in internal walls, ceilings, floors and the roof. Triple glazing was also used extensively throughout the property. We utilised specific materials such as clay blocks, rammed earth floors and the existing Victorian brickwork to regulate internal temperatures. Combined, this allowed us to make the switch from central heating to using just a wood stove along with solar thermal panels. The other major change was a Mechanical Ventilation Heat Recovery system installed throughout the whole house.
Benefits:
The new triple glazed roof lights and windows allow large amounts of high quality natural light all the way through the house. The triple glazed windows also utilize solar radiation whereby the low angle of the sun in winter transfers heat through the windows. In summer the windows are shaded from the higher angle of the sun by an ash tree, therefore keeping the house cooler. The house doesn’t overheat in summer (even during July 2013) and the day time and night time internal temperatures are relatively even due to the use of the high thermal mass materials (clay, earth, etc.).
The insulation installed in walls, floors and the ceiling has resulted in the current walls and roof being 16 times better than in the old building. The windows are 14 times better and the air-tightness of the house – which is particularly important – is 28 times better than in the old building.
A combination of the above measures means that no central heating is needed and 80% of the heat produced by the stove is used to heat water whereas only 20% is needed for heating.
There are tiny things like switching we might have done slightly differently but overall, I think it’s exceeded our highest expectations. We had no idea whether it could be done – retrofitting an old building to this standard. No one had done it, computer software was not available to model it, and so we didn’t know if it was really possible. On the latest figures, the home is not just 100% zero carbon, it’s 183% carbon negative!
Favourite Feature:
So difficult to pick one, but the quality of the natural light and the quality of the materials like the earth floors are favourites. The natural and reflected daylight and sunlight changes dramatically through the day and through the year. Even after four years here we’re still surprised by new effects of light we haven’t previously seen. We like the fact that we’re so in touch with the seasons. I think we notice the rhythm of the year much more living in this house than we did previously: we can touch a button and see how much solar electricity we have generated that day, or see what the temperature is in the solar hot water cylinder. That makes us conscious of the abundant “free” energy available most of the time, and helps us to think about whether we want to boost the hot water and the choice between having a bath or a hot shower.
