About 5 years ago we decided to put an extension on the side of the house but it has not been a success as it is always too cold in winter unless we spend a fortune on heating. It was built to current building regs, with large blocks of foam in the sub-floor, insulation in the walls, double glazed windows and two layers of insulation in the roof, but for some reason we are loosing a lot of heat. It is traditional build with brick outer, cinder block inner, dot and dab plaster board internal and a pitched roof on top.
I had been hoping for a really cosy set of rooms (living room and study) that would be built to need very little heating but it isn't and consequently we only use the rooms when we have to rather than as an extra integrated part of the house.
Does anybody have any ideas on what to do. My own suspicions are the french windows weren't installed as well as they could and leak air around the doors, also the dot and dab didn't include a solid line of goop top and bottom so that air is free to flow from attic to under the skirting boards.