Building regulations around the world require loft insulation to reduce heating and air conditioning bills. In the UK the minimum is 270mm (11”) and many houses have more than that. That’s much higher than your joists, which are typically only 100mm or less. But our research on loft usage showed that people want to use their lofts for storage and access purposes, and 82% squash 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 the UK, to test insulation when it was compressed. The results were worse than anyone thought; if you squash your insulation from 270mm down to a joist height of 100mm then its performance reduces by 50%. If you squash it down to 75mm joists, it loses 60%. So the heat lost at least doubles! You can see NPL’s coverage of this research in their own press release and download our own review of all the academic literature here.
That means that in the vast majority of buildings, loft insulation isn’t working the way it’s meant to. It’s a national tragedy which means that people’s heating bills are too high and that we are wasting the energy from up to 5 whole power stations each year. That’s why we developed LoftZone StoreFloor, which solves the problem of how to use an insulated loft for storage and access.
25% Heat is lost through your roof
Heat rises, and if you don't insulate your loft, 25% of your heat goes straight out of your roof. Source - Energy Savings Trust.