4 MAY 05

This morning I turned on my computer and downloaded seven overnight emails from our hard-working architect, Peter Smithdale. Among other things, they concerned ventilation ducts, underfloor heating controls, coping stones for our garden walls and shower drainage. In principle, our contractor is building a house that Peter drew seven months ago but in practice there is an endless stream of details to resolve, a process that potentially includes negotiations with contractor, site foreman, engineer, suppliers and (not least) an ambitious client with a time-consuming habit of pushing everything beyond standard practice.

We feel very lucky to have had Peter’s professional support over the last two years as he has achieved that rare balance of listening and challenging, empathy and imagination; every one of our ideas has been treated with critical respect so we feel deeply involved in the design of the house. Although Peter is a member of the Royal Institute of British Architects, he does not conform to the stereotype of the profession expressed by the alternative meaning of 'RIBA': 'Remember – I'm the bloody architect!'

It helps of course that Peter shares our interests; we approached his firm, Constructive Individuals (020 7515 9299, www.constructiveindividuals.com), because they were ecological architects with experience of working with self-builders. This was a good place to start, but what we've really valued is Peter's willingness to look beyond the technical aspects of our zero-carbon brief and work with our metaphor, to help us design a house that captures the spirit of a tree.

Although the question of what 'counts' as ecological building tends to focus on the details of construction and performance, there are many wider issues raised by this concept, not all of which are in the power of the architect to resolve. For example, is a house 'green' if the people who live in it still squander resources and burn fossil fuels in every way they can? Here we certainly hope to follow the lead of BedZED in south London (www.bedzed.org.uk) where very high performance housing is integrated with live-work spaces, car clubs, local food schemes, recycling and public transport.

At another level, ecological building can be understood as a creative response to the natural world. This, very much the architect's domain, may mean integrating buildings with their landscape and setting, exploiting organic forms in the shape of the building, or drawing on deeper principles of nature's design in the philosophy of a project. With Peter's support, we have sought to capture all these qualities in Tree House. The house is a respectful response to the mature tree that dominates the plot; the form of the tree is subtly picked up throughout the macro and micro design; and, above all, the house will work like a tree, drawing all its energy from the sun and thriving in harmony with its natural environment.

We were encouraged to imagine a house that captured the form and beauty of a tree by a building that Peter introduced us to: Alvar Aalto's Villa Mairea. A year ago we embarked on an odyssey by sea and road to a remote corner of Finland to visit this remarkable house which combines the discipline of modernism (it was built in 1938) with a richly detailed response to the forest in which it is built. It may not be an eco-house by today's technical standards, but its integration in its natural setting and subtle evocation of the forest in its design provide a fine example of what a modern response to nature can achieve.

Frank Lloyd Wright, whose Falling Water is another profound response to a natural setting, once said that physicians could bury their mistakes whereas architects could only recommend the planting of vines to their clients. I have already bought the vines - Ampelopsis megalophylla to be precise - but Peter can rest assured that these vines are an integral part of our summer shading strategy and are most certainly not a veil of embarrassment.