Internally insulating a wall

[nickjb]

Our bedroom has two external walls one is mostly window the other is rendered brick without a cavity. The bed is against the brick wall and the wall is very cold. Thinking it would be a good idea to insulate this wall. The window will still he a cold sink. It is featureless so hopefully fairly simple. What's the best way to go about this?

Celotex and plasterboard or insulated board? Batons or dot and dab? Do I need a vapour barrier or to leave an air gap?

 

[drpepe]

Our bedroom has two external walls one is mostly window the other is rendered brick without a cavity. The bed is against the brick wall and the wall is very cold. Thinking it would be a good idea to insulate this wall. The window will still he a cold sink. It is featureless so hopefully fairly simple. What's the best way to go about this?

Celotex and plasterboard or insulated board? Batons or dot and dab? Do I need a vapour barrier or to leave an air gap?

What heating do you have in the room?

Our old house had a bathroom with N, E and S facing exterior walls and a roof that was too shallow to insulate well. It was always very cold.

We considered interior insulation but in the end we just replaced the radiator for a much higher output one and it did the trick.

Much less expense and disruption.

 

[AronSearle]

Polystyrene insulation and plasterboard if you want cheap.

Insulated plasterboard is better (no different than celotex and plasterboard, but all in one).

Vapour backed plasterboard should be used (the insulated plasterboard will incorporate this).

What is the window? Single glazed, is it a typical window or a full height window, is secondary glazing an option?