JJ452

Certain - it's solid all round. I also looked into the hole where the sky cable was coming through and it's brick the whole way to the cavity wall. The property is a self-build by the previous owners so not a mass produced new build.

Great thanks, I'll seal the boxes. Should I be concerned about the air in the cavity wall where the sky cable was removed? I guess there isn't much I can do about this other than getting the insulation topped up?

Had to check - it is wet plaster straight onto the block. I took one of the sockets off to see if the cabling was through the block in any way but appears to be going up into the suspended ceiling where I assume the cabling is routed.

I've recently moved into the a new home during the summer and now as the temperatures are dropping I'm beginning to find the problems... The house was build in 2011 and is brick exterior (cement rendering) and brick interior walls with concrete slab floors. As far as I can tell it has polystyrene beads in the cavity wall (visible in the loft) and has 300mm loft insulation. I have noticed a number of issues which I have mostly addressed already - Window trickle vents leaking significant air Kitchen extractor fan ducting not properly sealed Poor door seals Loft hatch not insulated or sealing well The house now seems to hold heat reasonably as last night the minimum outside temperature was 6 degrees and over a 10 hour period from 11pm to 9am without any heating the open plan kitchen/dinning room dropped 1 degree (19 -> 18), hall dropped 0.5 degrees (19 -> 18.5) and living room 1 degree (22-> 21). One thing I can't figure out however is the cold air coming from the electrical sockets. Every single socket which is on a wall facing the exterior of the house is letting in quite a noticeable draft even when it's not what I would call windy outside - but not the sockets for interior walls. I confirmed this by checking the location we removed a sky cable which was drilled through the cavity wall and was sealed on the outside but not yet repaired on the inside and there was a significant amount of cold air coming from the cavity wall. Is this normal? I have read air needs to move within the cavity wall to prevent damp but surely it shouldn't be felt coming out of the sockets? If this is normal do I just seal around the socket with a fire putty pad?