In the push for zero carbon homes, what’s happened to good climatic design?

For anyone who hasn’t heard of it, the three-storey detached house was built in the mid-1990s and is on a north-south facing alignment with a large passive solar sun/buffer spaces. The fabric is airtight, highly insulated, and utilises high levels of thermal mass. Photovoltaic panels provide hot water and a wood burning Kakkleoven covers most of the space heating requirements. Internal door openings have been carefully angled to maximise through ventilation and on the hot summer’s day I was there, the internal environment was extremely comfortable.

Sue showed me charts (maintained since the construction of the house) highlighting how the internal temperature has hardly ever strayed over 21°C or under 15°C. Her quarterly gas bill last year was about £17, which, although double what it was in 2006, is still unachievable for most of us.

The government’s stipulation that all new homes should be zero carbon by 2016 means that in just eight years, all homes will be required to demonstrate very similar properties: this is going to require a massive step change. Considering that it has taken two years to come to terms with the last relatively simple changes to Part L of the Building Regulations (which will pale into insignificance when compared with future changes to the document), it is frightening to think that today’s development ethos seems to be light years away from zero carbon status, not eight years away.

The required fabric will be achievable, of that there is no doubt. However, what we seem to have forgotten is how to make our dwellings interact with nature and the communities they serve.

The following text (the words of Lady Catherine de Burgh to Elizabeth Bennett) is taken from Jane Austin’s novel Pride and Prejudice, which was published in 1813: ‘“You have a very small park here,”’ returned Lady Catherine, after a short silence. ‘“This must be a most inconvenient sitting-room for the evening in summer: the windows are full west.”’

So historically, good climatic design was an important feature of buildings. How many of today’s housing developments pay even scant regard to such matters? Fine terraced town housing used to create close-knit communities while minimising heat lost through external walls. This may help explain why terraced properties have experienced the fastest rising house sales of any property type over the past 10 years – but does not explain why developers continue to produce estates that primarily consist of semi-detached and detached properties that are more difficult to orientate successfully.

The planning approvals process does nothing to encourage good climatic design and barring a few well-known modern examples of north-south facing alignment and good passive solar design – such as Bill Dunster’s BedZed development in Sutton and ZEDfactory’s current ruralZed system – UK housing design is not, in the main, taking such matters into account. The lack of a consensus or reliable methodology has so far discouraged planners from playing their part. If they were to be given clearer guidance, planning and Building Control bodies could clearly be examining these issues together, right now.

It is obvious that the government is waking up to this issue as it is touched upon briefly in the recent consultation paper The Future of Building Control. However, eight years is not a long time and regulatory bodies should not be waiting for planned legislative changes to instigate further change.

Through one definitive reference – not the many conflicting documents currently available – we should be encouraged (and should be encouraging others) to promote future best practice today, in parallel with ensuring that current minimum standards are met. The fact that SAP 2005 allows closed curtains to provide a home’s solar shading shows how far we still are from recognising the true power of thermal mass and good climatic design.

During our meeting, Sue Roaf likened running the Oxford Ecohouse to sailing a ship: she is using the environment to get her to where she wants to be. With the breeze steadily building towards 2016, there is already a danger that many homes in the UK in 2016 and beyond will be stuck in a dead calm.