30 NOVEMBER 05

I've had enough of being environmentally friendly. In fact, I'm fed up with the whole idea. It's really rather last century don't you think?

Don't worry, I'm not writing this from a 4x4 on the road to Damascus. I'm merely questioning the usefulness of the term 'environmentally friendly'. For starters, it is hopelessly vague, meaning anything and nothing and often disguising a multitude of sins. More importantly, it is just too wet. A little extra 'environmental friendliness' will not save the world from ecological catastrophe, especially if this appears to be no more than one consumer choice among many.

If we are to make a radical difference to our environmental impacts, we need to build and design with radical intent. The influential book 'Factor Four' (Earthscan 1998) argued that four-fold improvements in the environmental performance of products and buildings are already well within our grasp. All we need is the ambition.

The area where this matters most is energy. If the speed of glacier flow in Greenland has increased by a factor of 100, we need to up our game fast. Although every environmental impact of Tree House is of concern to us, our greatest efforts have been focussed on reducing energy consumption, hopefully to a level that we can provide for using our own on-site renewable supply.

Most of the energy burnt in UK homes is for space heating, so we have put lots of effort into our insulation and air-tightness. But as electricians Simon and Dave complete the internal wiring in Tree House, I have been reviewing our plans to keep our electricity consumption as low as possible too.

When people are asked to identify the principal source of electricity use in their homes, the most common reply is the washing machine. In reality, this is some way down the list. The really big burner is lighting. Here factor four is easy: all the lights we are installing in Tree House are compact fluorescents, every one of which achieves at least a factor five improvement over its tungsten equivalent (7W instead of 35W, 11W instead of 60W). Thanks to the work on bulb miniaturisation of our supplier, Megaman (www.megamanuk.com), we will be using this technology not only for globe bulbs of all sizes but also for candle bulbs and ceiling recessed downlighters (instead of halogens).

The energy efficiency of kitchen appliances has improved considerably over the last ten years but the worst fridge on the market will still use twice the electricity of the best (for the latter, see the Energy Saving Trust database at www.est.org.uk). And you'll get a factor 160 improvement for using a washing line instead of a tumble dryer (hanging out the washing uses about 0.025 kWh of your energy vs. 4 kWh for the tumble dryer).

Regrettably electronic gadgets such as televisions, audio and computers rarely have energy labels so there is more scope for screwing up here. Do you want a plasma screen when it uses nearly twice the energy of the alternatives? Do you want an amplifier that makes a virtue of the size of its transformers? Above all, do you want a desktop computer when it consumes ten times more energy than a laptop?

A few lightbulbs and a laptop computer might not seem like a radical agenda for change but if everyone paid attention to these details we could abandon a clutch of power stations and stop worrying about new nuclear build.

Environmentally friendly? Bah humbug. We take and take and the environment gives and gives. Our long-suffering friend may be losing patience, but if we are honest to ourselves, there may still be time to save the relationship.