Donnachadh McCarthy: The Home Ecologist

Soon after I began eco-auditing, I was asked to assess a businessman's apartment in the East End of London. He already had a low carbon footprint for his home, and I congratulated him on this when sending him his report.

He emailed me back to confess he had not told me about the holiday home in the South of France and his air travel; he took about eight flights to France every year to this holiday home. His flights added up to about 7.3 tons of CO2 emissions, or about seven times the annual emissions from his flat. As we can afford at most about one ton of CO2 per person, his holiday home flights alone exceeded his total annual quota. For a family of four, these numbers accelerate alarmingly. For example, if a family of four in Britain has a holiday home in Miami and takes eight trips a year, their flight emissions would be nearly 11 tons, or twice what the average UK home emits every year.

And that is just the carbon footprint for getting there. Bill Dunster of ZEDfactory estimates that about 15 years of CO2 emissions are used in building a home. This could represent an astonishing 90 tons of CO2 emitted building a holiday home – and we have yet to factor in the energy used for driving, heating, cooling and lighting used while holidaying there. A generous estimate would put this at only one ton. Thus a rough estimate of the CO2 emissions involved in building a new holiday home in Miami, and travelling to and staying there in the first year, would be a planet-destroying 102 tons.

No matter how eco-friendly the development, no matter how many solar panels or energy-efficient light bulbs it has, there is no way that a holiday home in Miami – or for that matter anywhere one has to fly to – could remotely be described as an eco-holiday home. To be blunt, just as the most eco-friendly car is the one you don't have, the only eco-holiday home is the one you do not own!

However, if you really must have a holiday home, three simple rules will help. First, buy an eco-refurbished existing home, which will slash the CO2 emitted in building and running it. Second, buy a holiday home that's reachable by train or public transport. This will cut the emissions produced getting there. Eurostar means that large parts of Europe now qualify for this.

Finally, ensure that the home is rented out when you aren't there. Building millions of holiday homes for rich Europeans that lie empty most of the year is one of the most criminally wasteful actions we could possibly take.

So the next time you are tempted to buy a holiday home, don't think twice about it, think three times. Alternatively, become a green hedonist and book yourself a first-class train journey to Europe and stay in a luxury yoga or spa centre. You'll not only have eco-peace of mind but will save loads of money and hassle into the bargain.

Donnachadh McCarthy works as an eco-auditor and is the author of 'Easy Eco-auditing' ( www.3acorns.co.uk)