Building codes around the world require attic insulation to reduce heating and air conditioning bills. The depth of insulation depends on your climate and the material you use (for example, see the R-values recommended by the US Department of Energy) but is always much higher than your joist height, which is usually only 4” or less.
But our research on attic usage showed that people want to use their attics for storage and access purposes, and 82% compress the insulation with boxes or boards. This is against insulation manufacturers’ instructions, because insulation works through the trapped air inside it. But just how badly does it affect its performance?
We commissioned the National Physical Laboratory (NPL), the premier testing agency in Great Britain, to test insulation when it was compressed. The results were worse than anyone thought; for example if you squash your insulation from 11” down to a joist height of 4” then its performance reduces by 50%. If you squash it down to 3” joists, it loses 60%. so the heat transmitted through the insulation, at least doubles, increasing heating or air-conditioning bills. You can see NPL’s coverage of this research in their own press release.
That means that in the vast majority of buildings, attic insulation isn’t working the way it’s meant to. It’s a tragedy which means that people’s heating or air-conditioning bills are too high and that we are wasting the energy from too many power stations each year. That’s why we developed LoftZone StoreFloor, which solves the problem of how to use an insulated attic for storage and access.
25% Heat is lost through your roof
Heat rises, and if you don't insulate your attic, 25% of your heat goes straight out of your roof. Source - Energy Savings Trust.