Cold Garage Conversion

Dry line the walls, and if possible, the floor. You should already know what to do with the roof.

I've a feeling they already are, certainly sounds hollow enough when you tap it...

Ah, but is it insulated?

When was the conversion done, and is there any evidence that the appropriate building regs were complied with?

Was the garage integral with the house or just adjoining. You find that the outside wall is only single brick eg no vavity wall. This is what happened to my neighbour.

Alan R

The basic answer is to add insulation (or more). Dry lining is the usual way. You may already have the plasterbord lining etc, but no insulation behind.

Taking it down and adding a rigid PIR foam board, or using a foam backed plasterboard would be one fix.

Not if they are done now, and with building control oversight. They need to be pretty close to new build standards or as close as you can get without going to silly lengths.

I have seen that done before on an integral garage. The garage door was bricked up with a single skin on the outside with just studwork and plasterboard with no insulation internally.

The OP needs an IR thermometer to find the cold spots.