David Hammond at his house at 34 East Street shows how it is possible to achieve the ‘40% house’ in existing, refurbished houses, not just new ones. His house currently uses 38% of the energy demand for the average UK house. ClimateX interviewed David about his experiences.

Motivations

I was motivated primarily by the certainty of ideas I'd had for many years about using the combination of heat pump, solar collectors and underfloor heating together as a viable low cost long term "green" solution to domestic heating requirements, large and small.     For many years, since my solar / heat pump thesis at college in the early 70s, I had tried in vain to persuade clients to consider the obvious possibilities.  Eventually I realised I had to do it myself!!
        Heat pumps work more efficiently the closer the ingoing and outgoing temperatures are.  Solar heat is potentially low grade, and underfloor heating is best at low temperatures.  The combination of all three is a "perfect marriage".

Inspirations

Inspiration was obtained many years ago at college learning about heat pumps, particularly installations in the United States in the 50s.  Zarem & Erway edited an interesting book, now out of print.  The Oil Crisis of the early 70s was a ‘catalyst' that motivated me to do the research - but then it was about finding resources to replace oil, and saving money, not primarily the planet.

Challenges

The challenges were mainly to do with dealing with builders, plumbers etc,  who were unfamiliar with  the ‘new' technologies,  and red tape regarding water extraction from the Thames (Environment Agency, EA),  and digging up the road for the pipework [Oxon County Council].  Filtration problems, both for the EA and heat pump requirements, necessitated a detailed design for the bankside installation.  The work was done before grants were available.

My favourite feature

Because heat pump and solar collectors feed into a large ‘thermastore', and controls are organised so that any available solar satisfies demand before heat pump, my favourite moments are when the weather is cold but sunny and the large array [7.5Msq] solar collectors alone are providing space heating via ‘thermastore' and underfloor heating pipework.  

My vision of Oxfordshire rising to the challenge of climate change

American prof. Robert Cialdini says people will change their behaviour when new approaches are seen as the norm of good sensible behaviour.  In other words it is up to those who can, and particularly those that are in the public eye, to demonstrate that ‘going green' is normal good behaviour.  I would like to see prominent responsible individuals and corporate / government bodies in Oxfordshire leading the way.

What, to you, is the biggest opportunity that climate change presents?

I don't see climate change as 'presenting many opportunities', it demands that we look at:  all ways of saving energy and reducing emissions, all ways of providing alternative safe sustainable energy supplies, in all places possible, at all times.  

One word about how you feel about climate change?

frightening

Next steps

What we are doing next is working on a vision for scaling up the experience we have had with our house, to an understanding of how it might be possible for whole communities to do their bit to achieve the 60% plus demand reduction we know we need.  We have recently submitted an entry to an American competition on this basis and would be pleased to share the results with you, although it would take more than 70 words!

Last words

Contrary to some strangely reputable sources (i.e. Guardian, BBC World at One) solar thermal collectors, if properly integrated into the system, do not have long pay-back periods.   I reckon 10 to 15 years for our installation.  Modifying one's behaviour also helps.  We try to get the washing done when the sun's out - the PVs help supply the electricity and the solar thermals the hot water !!

David's contact details:

 David Hammond Architect RIBA
    34 East Street, Oxford,  OX2 0AU
    tel:  01865 245047
    www.hammondarchitect.co.uk