Draught proofing/insulation help please

elsien

Wooden floor with an air brick. Floor is carpeted But there is a built-in seat in the bay window where the air brick is, and bare boards within it. So that corner of the room is more draughty.
I’m not up for lifting floorboards or anything like that at the moment, but was wondering about whether  shoving some carpet tiles in there would help (just because I have some sitting around) or whether getting some insulation board to sit on the floorboards would be more effective?

FreeBear

What I did in my lounge was to cover the floor with aluminium foil (extra wide Bacofoil) topped off with 5mm thick woodfibre laminate underlay*. This killed all the nasty draughts coming up between the floorboards and provided a small amount of insulation. Foam underlay & carpet finished it all off. If you are not worried about the extra height and there is no foot traffic, then 25-50mm of EPS (Jablite) or PUR (Celotex) should work.

*) https://www.screwfix.com/p/diall-wood-fibre-underlay-boards-7m-15-pack/7824r

*) https://www.screwfix.com/p/vitrex-premier-wood-laminate-underlay-boards-9-76m/68038 - Slightly better value per square metre.