How they are built
Insulated garden rooms, explained properly
An insulated garden room is only as good as its envelope. Here is exactly what goes into a Pent Haus kit, layer by layer, so you can compare it fairly against anything else you are quoted.
Layer by layer
The roof
100mm insulated SIPs panel finished in seamless EPDM rubber, with guttering and downpipe included. No joins means nothing to fail.
The walls
100mm SIPs with 70mm insulation and patented concealed wiring channels formed inside during manufacture. Fixings can be hung anywhere.
The floor
Double joists every 600mm, giving a floor load capacity of 306–382 kg/m². Strong enough for gym equipment and workshop machinery.
The foundations
Heavy-duty composite posts concreted in, with a bolted stainless steel frame that lifts the room off the ground. 9–30 posts depending on size, and it copes with slopes.
The glazing
Argon-filled double glazed toughened units in the windows, and premium uPVC double glazed doors with multi-point locking.
The cladding
ToughWood engineered wood, compressed under extreme pressure: ultra tough, PVC free, PEFC certified and maintenance free, in six colours.
Three structure types
| Kit | Build time | Insulation | In short |
|---|---|---|---|
| Signature SIPs | 1–3 days | 100mm walls with 70mm insulation, 100mm EPS in floor and ceiling | Our best performing kit. Insulation, internal wood panelling and the electrical channel system are all included. |
| ToughFrame Pro | 4–5 days | 60mm PIR in walls, 70mm EPS in floor and ceiling | Insulated timber frame at a lower price point. Suitable for year-round use in all weather. |
| ToughFrame | 4–5 days | Uninsulated shell, ready for you to add your own | The most affordable entry point: a strong weather-resistant shell with composite cladding you can line later. |
ToughFrame and ToughFrame Pro have a 20cm reduction in depth compared with Signature SIPs.
Why insulation changes what the room is for
An uninsulated summerhouse is usable for perhaps five months of the year. A sealed, insulated envelope turns the same footprint into a room you use in February: a working office, a gym you go to at 6am, a therapy room a client will sit in comfortably.
It also keeps running costs down. Heating a well-insulated 3.6m x 3m room takes far less than most people expect, and in summer the same envelope keeps the heat out.
See it in use across our gallery and local case studies.
Common questions
See your garden room, and its price, in minutes
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