Empty vs full loft

geordie_ben

I've done some googling and can't find the answer

Which is more efficient, having an empty loft, or storing things in it?

It already has the recommended insulation

matelodave

It probably doesn't make much difference, unless the stuff you store up there sits on the insulation and compresses it down, in which case it will make it worse.

If you've already got the recommended amount, say 300mm, then adding another 300mm will probably cost you a lot more than you'll save. Boxes and other stuff wont have the same insulation value as proper insulation and it would depend what's in then as well.

If you filled the loft completely with carboard boxes full of clothing or similar then you'd probably get a little benefit but it would be hard to quantify

The first 300mm saves the most, whereas the second 300mm will only save half as much - you need to do heat loss calcs to see how it works

geordie_ben

I'm not thinking of putting more insulation down. Was wondering if storing boxes etc would help

I'm guessing boarding out the loft, even without putting boxes on, would improve efficiency?

Pincher

You can lay down some old curtains, on top or below the boards.

Always think ventilation, so plastic sheets that trap moisture is bad.

Apodemus

You don't mention whether the insulation is on the loft floor or the underside of the roof. The thermal mass of whatever you are storing will alter, to some degree, the rate of heating and cooling of the loft space. If that is within the insulated (and presumably heated) envelope of the house, then this will have some degree of influence on the buildings "efficiency". But unless you are storing materials of high thermal mass, the effect is unlikely to be noticeable.

Jonesya

Main thing is having it well insulated with 270mm of insulation all over and making sure the hatch is well insulated and draught-proofed. They're the things to focus on.

Boarding it out and storing items up there makes no difference, and if you start squashing insulation under items or boards, or removing insulation to put the boarding down it could make it worse.