Sir Jonathon Porritt, chairman of the Sustainable Development Commission, has declared that the world’s one billion overweight people are responsible for an extra one billion tons of CO2 emissions a year

By eating beef and lamb, and by taking to the car more than most, the fat join families with more than two children in the chivalrous knight’s gallery of rogues.

He has laid down a bulky challenge to building designers. No more lifts – make exercise compulsory and so get people into the habit of walking more. No more car parks, for the same reasons; also, longer corridors, and poor signage, so the plebs can be given more chances to get lost. 

Let’s have slimmer door frames, and perhaps more revolving doors, to nudge people into thinking about and working on their diet. Kitchens should be equipped with ovens that can only take chickens at most. Wider pavements, and no roads – these are what New Labour rightly labels obesogenic.

There is much to be done. Top task on the SDC’s website is ending economic growth, because of its damaging effects on the environment. Let’s hope that building designers, a fatcat profession, rally to Sir Jonathon’s cause!

James Woudhuysen, London