# Garden Room Insulation: Floors, Walls and Roof

A garden room only works year-round if it's properly insulated. Without insulation, a timber building is too cold to use in winter and too hot in summer. Garden rooms are simple structures, though, and the same few products cover the floor, walls and roof.

## Do you need Building Regulations approval?

In England, detached garden rooms with no sleeping accommodation are generally exempt from Building Regulations if they're under 15m², or up to 30m² if they're at least 1m from the boundary or built substantially of non-combustible materials. Planning rules are separate. Check with your local council if you're unsure. Even where the regulations don't apply, insulating to a similar standard is what makes the room usable.

## The floor

Most garden rooms sit on a timber frame over a concrete base or ground screws. Fit [PIR boards](/collections/pir-insulation-boards) tightly between the floor joists, supported on battens, then lay the deck on top. On a concrete slab, lay a damp-proof membrane, then PIR boards, then a floating deck of [plywood](/collections/ply) or OSB.

## The walls

Garden room walls are usually timber frame, built up from outside to inside like this:

1.  External cladding
2.  Battens, to create a ventilated gap behind the cladding
3.  Breathable membrane
4.  Sheathing board (OSB or plywood)
5.  [PIR boards](/collections/timber-steel-frame-boards) between the studs
6.  Vapour control layer with taped joints
7.  Plasterboard or another internal lining, or [insulated plasterboard](/collections/insulated-plasterboard) to boost performance and cover the studs

The vapour control layer on the warm side is the part most often skipped, and it's the one that stops condensation forming inside the wall.

## The roof

Garden rooms usually have a flat or shallow mono-pitch roof. Build it as a warm roof: deck, vapour control layer, [PIR boards](/collections/pir-insulation-boards) on top, then the waterproofing. This keeps the timber warm and dry and avoids the need for roof ventilation.

## Keeping it cool in summer

Well-insulated rooms with lots of glazing can overheat. Shading, windows that open on two sides and avoiding large west-facing glass all help. Our [summer overheating guide](/blogs/smart-advice/how-insulation-prevents-summer-overheating) explains how insulation behaves in hot weather.

## Quiet offices and studios

For a music room, or a garden office near a busy road, use [acoustic roll](/collections/acoustic-partition-roll) in the stud walls and line them with [sound board](/collections/sound-boards).

## Typical materials list

-   PIR boards for the floor, walls and roof
-   Breathable membrane and vapour control layer (see [membranes](/collections/membranes))
-   OSB or plywood for sheathing and decks (see our [OSB vs plywood guide](/blogs/smart-advice/osb-vs-plywood-which-sheet-material-do-you-actually-need))
-   [Timber](/collections/timber) for the frame and battens
-   Plasterboard or insulated plasterboard, foil tape and fixings

## Garden rooms near you

Garden rooms are popular in commuter areas such as [Surrey](/pages/next-day-insulation-surrey) and [Hertfordshire](/pages/insulation-supply-hertfordshire), and we deliver across most of England.

Send us the room dimensions at sales@nextdayinsulationltd.co.uk and we'll work out a full materials list.

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> Source: [Next Day Insulation](https://nextdayinsulations.com/pages/garden-room-insulation)