The single most common cold-room call we get in Basingstoke, why it happens, and the fix that actually holds.
That bedroom is not badly heated. It is sitting on an outdoor space with almost nothing in between.
What is actually going on
A room built over a garage or car port sits on a floor with cold air underneath it, not on another heated room. Often the walls are thinner than the rest of the house too — single skin, or an add-on to the original build. That bedroom is not badly heated. It is sitting on an outdoor space with almost nothing in between.
Turning the radiator up fights the physics and loses. So does putting a rug down.
The three surfaces that need attention
The floor. This is the big one. From below, insulating the garage ceiling is usually straightforward and is the single most effective move — rigid board or closed-cell foam between and under the joists, fully sealed at the edges.
The external walls. Where the wall is single-skin or solid, internal insulation makes the room usable in January. Reveals and lintels have to be carried through or you swap a cold room for a mouldy window.
The junctions. The perimeter where the floor meets the external wall is a textbook cold bridge, and it is where the mould appears first. Insulating the middle of a surface and stopping short at the edges is why half-done jobs feel barely different.
Do you have to do all three?
Not always. If the walls match the rest of the house and only the floor is exposed, insulating from the garage side may be enough on its own — and it is the cheapest of the three. If the room also has a thin extension wall or sits under a flat roof, doing one surface will disappoint.
That is exactly what a survey is for: working out which surfaces are genuinely losing the heat, in what order to treat them, and what the room will feel like afterwards. We do it free, and we will tell you if one cheap element solves it.
Related service
Wall Insulation Basingstoke
Internal wall insulation for cold, solid-wall rooms
See Wall Insulation Basingstoke
