This post originally appeared on Orphan Road.

According to the BBC, the average new US home is 2,300 square feet, while the average new UK home is 818 square feet.  Yet they seem to get by just fine in life.  Let’s take a look at those numbers.

First let’s compare two homes with the same weather conditions in somewhat cold region.  Seattle isn’t too different from rainy England, so we’ll use a cold Seattle winter day of 35 degrees F. 

Wall Area (sf) 2170 1293
Window Area (sf) 542 323
Roof Area (sf) 1380 490
Heat Loss (kBTU/hr) 12.8 7.3
Electricity (kW) 4.6 1.6


So you can save 43% on heating and 65% on electric use by having a UK sized home. 

Assumptions:  To be fair, I assumed the same building codes exist. I assumed 20′ tall (at the exterior walls) 2-story homes with a window-wall ratio of 20%. I looked only at heat conduction – factoring in air loss would show more energy savings in the UK model. I used 2009 WA energy code values for walls and windows. I assumed 2 W/sf for electrical energy – this is a very rough estimate, and more useful for percentages.  Electric use is assumed to scale linearly with square footage because lighting typically dominates electric use, and a larger home will typically have more electric equipment.