1 MARCH 06

After three months of drought it poured with rain on Sunday, the day Ford and I finally moved into Tree House. We started work at 7.00am and my mid-morning the short distance from the back of the transit van to our new front door had become a treacherous mudslide. Every precarious traverse across it was followed by a heavyweight push up two flights of stairs to the only habitable room in the building. By nightfall we were flagging badly with no end in sight - the removal fairy kept conjuring up piles of neglected possessions in our Brixton flat whenever our backs were turned.

Just at this moment, when dirt, exhaustion and disorientation threatened to overwhelm us, a passer-by stopped and asked us if we were the owners of the house. She went on: "It's gorgeous. It's a real statement. I love it being on my road where I can see it every day". We nearly wept into our cardboard boxes.

My first column in these pages appeared on September 1st 2004, exactly eighteen months ago. I knew then that the building of Tree House was unlikely to be straightforward, given how far we had pushed our ecological specification, but if anyone had told me then to prepare for a journey lasting a year and a half I would have scoffed. After all, we were building a two bedroom house on a small site in Clapham, not some elaborate mansion in the country.

This time last year, six months in, site stalwarts Steve and George were still absorbed with ground works. It was a bleak time and I struggled then to maintain my enthusiasm but such private wobbles never lasted long. Whatever stage the build was at and whatever problems we faced, the tree was always there, strong and graceful, to sustain our vision.

The exceptional ecological performance of the tree provided us with a truly challenging goal for the house, a standard far beyond any current definitions of good practice in the building industry. We cannot claim to have met this standard in every detail but we have done our best and fought off a legion of compromises.

Beyond this ecological goal, at the very heart of our ambition, lies the sheer beauty of our tree. Even in the heart of winter its vaulted form, organic density and depth of texture are an inspiration. It has been exciting and interesting to build a house powered entirely by the sun but the greatest personal reward lies in the creation of a house that is beautiful.

Very occasionally, when the accumulating evidence of global climate breakdown saps my optimism, I wonder what difference our radical eco-specification will actually make. But I have no such doubts about acts and works of beauty. After all, if we cannot sustain a delight in life itself, whatever future we face, what is it that we are fighting to preserve?

Finally, we must thank the many people - professionals, labourers, craftsmen and artists - whose imagination, commitment and hard work have brought Tree House into being, above all architect Peter Smithdale, contractor Martin Hughes and site foreman Steve Archbutt. Everyone who worked on this job cared about it and, thank God, it shows.