Apparently, something called an energy performance certificate was necessary for the house. This involved an inspection by someone who knew something about saving energy and an estimate of how much money someone thought might be saved if something was done to save energy.

The details that came with the certificate explained how the energy rating might be improved by taking energy saving measures. The biggest single measure suggested was that of installing solar panels: it was estimated that £238 per year might be saved by spending £9,000-£14,000 on the panels.

For someone with cash to spare, it would be a worthwhile investment. Yields on savings are so low that a return of £238 on £9,000-£14,000 might seem attractive. It would be comparable to an after tax yield of 1.7%-2.6%, and no institution can offer a comparable rate of return at the moment. Of course, for someone who does not have £9,000-£14,000 to spare, there is not the opportunity to save on energy.

Rich people can always live more cheaply than poor people. The idea that being rich means you can spend less money seems counter-intuitive, but becomes obvious when you think about who can travel to buy goods, who can buy in bulk, who can dictate the price they wish to pay, and who can obtain credit on the cheapest terms.

The idea of the rich living more cheaply than the poor is explored by Terry Pratchett in his novel Men at Arms: The Play. The logic of Captain Vimes in the novel is irrefutable:,

“The reason that the rich were so rich, Vimes reasoned, was because they managed to spend less money.

Take boots, for example. He earned thirty-eight dollars a month plus allowances. A really good pair of leather boots cost fifty dollars. But an affordable pair of boots, which were sort of OK for a season or two and then leaked like hell when the cardboard gave out, cost about ten dollars. Those were the kind of boots Vimes always bought, and wore until the soles were so thin that he could tell where he was in Ankh-Morpork on a foggy night by the feel of the cobbles.

But the thing was that good boots lasted for years and years. A man who could afford fifty dollars had a pair of boots that’d still be keeping his feet dry in ten years’ time, while the poor man who could only afford cheap boots would have spent a hundred dollars on boots in the same time and would still have wet feet.

This was the Captain Samuel Vimes’ ‘Boots’ theory of socioeconomic unfairness.”

Vimes is a man who would have shook his head at the thought of being unable to save £238 per year.