Why is my floor so cold?

[GoldenOmber]

Previous owners built an extension on to living room. Judging by the other work done on the house, extension may not have been carried out to particularly high building standards. Anyway, the floors in that bit of the room are ALWAYS cold and it seems to be coldest near the external walls. The walls themselves are not cold to the touch, but the part of the carpet where they join the floor is freezing, like there's always a draught through it. Middle of the carpet is fine.

I don't know what the walls are made of, whether they're insulated, what the floor's made of or anything. I do know that the decorators who painted the ceiling said that the wall was not properly taped (??) to the ceiling on the extension.

Would like to get this fixed at some point, but I'd also like to mentally prepare myself for whether this is a cheapish job or a rip-all-the-walls-out job. Any guesses for WTF might be going on and what sort of scale of work it might take to fix it?

you need to find out if ther floor is concrete or "wood." Lifting the carpet or vinyl may be necessary, though with practice you can tell by hitting it.

there may be a cold draught coming under the skirting boards. This tends to carry dust and dirt, staining the carpet or floor black at the edges. It can be fixed.

Look round the outside of the building. Wooden floors, with a void underneath, should have ventilation by airbricks at around 2-metre intervals, just below floor level, on the external walls.

Do the external walls appear to be made of bricks? Take a photo showing the brickwork pattern please.

Measure the thickness of the walls at a door or window opening. It may be around 13" or around 9".