Diary Of An Eco-Builder

How to generate your own energy, shun toxic materials - and still enjoy all the mod-cons

It's a tad surreal, but the expression seems to capture our nervousness about the risks of radical action. For our Clapham self-build, the proverbial bathwater consists of all the conventional assumptions about how houses should work, the usual compromises about carbon emissions, pollution, resources and waste.

If it is possible to generate all your own energy, use entirely non-toxic materials and send next to nothing to landfill, why do otherwise? Given public suspicions of what this involves in practice, however, we are also very focussed on our baby: domestic bliss with all mod-cons. We are confident that contemporary environmental design not only holds on to this baby but significantly improves its health. Ford and I plan to enjoy life in Tree House without any sacrifice in quality of life and all the benefits of a warm, light-filled, healthy home.

Which brings me to the important issue of our bath. London is the most water-stressed city in Europe, the South-east has just been through the driest eight months since 1975 and the Environment Agency is urging us all to take showers instead of baths. So you might expect me to have removed the bath from our radical environmental specification. Except, of course, this would involve throwing our quality-of-life baby out with the eco-compromised bathwater.

The key issue is not so much owning a bath but how often you use it. For us, baths are not instruments of cleanliness but of relaxation, designed to meet a very particular need after (say) a long day digging the allotment. As this need is relatively infrequent, we take few baths. But when the need does arise, nothing can replace a good soak.

A typical bath uses 80 litres of water compared to only 30l for a shower, so it makes good sense to opt for a shower for ordinary ablutions. However, showers are more convenient to use than baths as well as more water-efficient, so if you currently live without a shower, don't rush to install one if your twice-weekly bath will be replaced by daily showers. Above all, if you are planning to install or improve your shower, don't be tempted by a power shower - an environmental design disaster that uses more water than a bath for a marginal gain in physical sensation.

Instead, choose a shower with a low-flow option on the showerhead and responsive controls that encourage quick stop-start actions: stopping to lather up, restarting to rinse off (see www.hansgrohe.co.uk).

Having made it on to the specification, the bath for Tree House (currently in our back yard) comes with excellent eco-credentials in every other way. First, it's salvaged: an old roll-top bath I bought at auction for a knock-down price. Second, the original surface is intact, so the toxic and highly energy-intensive process of re-enamelling is not required. Third, we are replacing the rusted taps with a pair of new globe cocks which will fill the bath rapidly and so minimise heat loss before you get in. This is the opposite strategy to all the other taps in the house, which have built-in flow restrictors and aerators to give the best results for the least water throughput (Hansgrohe taps include these as standard).

To really save water, there's always the self-cleaning option. Not easy for humans, but a highly effective feline strategy. As our four cats are not only self-cleaning but also integral to our quality of life, there's absolutely no way, real or proverbial, that these babies will ever get thrown out with the bathwater.