Summerhouse, log cabin or garden room: which do you need?
Updated
All three give you a room in the garden. What separates them is how much of the year you can use it, and that comes down to the walls, the insulation and the glazing.
What's the difference?
A summerhouse is built for the warmer months: a timber frame clad in shiplap or tongue and groove boards, with large windows and glazed doors. Most aren't insulated, though some makers say they can be used all year.
A log cabin is built from solid logs that slot together and interlock at the corners. Thicker logs make it sturdier and warmer, so the thickness decides how much of the year it suits.
A garden room is the insulated option. It has double-skinned walls with insulation inside, an insulated roof and floor and double glazing, so you can use it all year round.
The names overlap. Waltons says really big summerhouses are often called garden rooms, Dunster House makes insulated log cabins, and one Waltons insulated garden room is also listed as a contemporary summerhouse. Go by the specification, not the name.
How do they compare?
| Building | Built for | Walls | Insulation and glazing | Base |
|---|---|---|---|---|
| Summerhouse | Spring and summer. | Timber frame with cladding, often around 12mm; some makers go to 16mm. | Usually none. Windows are often styrene or polycarbonate, which won't shatter; glass is available on some. | Firm and level. Slabs or concrete; timber decking suits smaller ones. |
| Log cabin | Summer days to all year, depending on the logs. | Interlocking solid logs, from 19mm to 44mm or more. | Thicker logs insulate better. Double glazing is standard with several makers. | Heavier than a shed. Concrete is the strongest; slabs suit a small cabin. |
| Garden room | All year. | Double-skinned panels with insulation between the timber, such as 72mm. | Insulated walls, roof and floor, with double glazing. | Firm and level: concrete, slabs or, for some, a suitable timber base. |
How thick should log cabin walls be?
A standard shed has 8 to 12mm cladding. Log cabins usually start at 19mm, and the thicker the log, the better it holds heat. Makers agree on that but draw the lines differently:
- Waltons: 19mm or 28mm for summer days, 34mm for summer evenings and spring, 44mm for use all year.
- Dunster House: 45mm is ideal for use all year, and its 62mm insulated wall (timber with an insulation core) gives the U-value of a 140mm wall.
- Power Sheds: 44 to 70mm if you want it warm all year.
Where a maker gives a U-value, lower means less heat lost. Logs are a natural material, so even kiln-dried timber can move a little with the weather.
What about the floor, roof and glazing?
Look for a tongue and groove floor on pressure-treated bearers, which lift the building off the ground and away from damp. Some log cabins come with 19mm roof and floor boards; an insulated garden room adds insulation to the roof and floor as well as the walls. Glass is more common on log cabins than on summerhouses. For use all year, Waltons advises double glazing alongside 44mm logs.
What base does each one need?
All three need a firm, level base. A poor one lets the building shift, which sticks doors and windows and can crack it. Log cabins are heavier than sheds, especially with thick logs, so Waltons says a wooden base isn't suitable for one: slabs are fine for a small cabin and concrete is stronger. Makers differ on the alternatives: Power Sheds and Dunster House both suggest gravel-filled plastic grids, and Power Sheds says to lay a damp-proof membrane under a new base. Timber decking can take a smaller summerhouse but not a larger building. Our guide to shed bases covers each type.
What changes if you'll use it all year?
Warmth. For the odd chilly evening, a small electric heater is often enough. For use through the winter, choose thicker logs or an insulated garden room, with double glazing.
Electrics. Power to a garden building should be put in by a qualified electrician, who can certify the work and give you a certificate to keep. Buried cable has to be the right type, at a safe depth, so leave that to them too.
Rules. A small garden building that nobody sleeps in usually doesn't need building regulations approval or planning permission. A bigger one, one close to the boundary, or one you'll sleep or live in can. Our guide to planning permission covers what to check.
Which should you choose?
- Summerhouse if it's for sunny afternoons and summer evenings, and light and views matter most.
- Log cabin if you want something sturdier that can stretch into spring and autumn, or all year with 44mm logs or more.
- Garden room if it's an office or studio you'll use every day, whatever the weather.
What to look for in the specification
- Wall or log thickness in mm, and a U-value if one is given.
- Whether the walls, roof and floor are insulated.
- Glazing: glass or styrene, single or double.
- Floor and roof board thickness, and pressure-treated bearers.
- Floor area in square metres and the overall height.
- The base the maker asks for.
Please note: this guide is general advice, not professional or legal advice. You are advised to check the planning and building rules with your council, and to have any electrics fitted and certified by a qualified electrician.
Sources
- Waltons: Summerhouse or log cabin?; Ultimate guide to buying a summer house; Ultimate guide to buying a log cabin; DIY insulated garden room; How much does a garden room cost?
- Power Sheds: Guide to buying a log cabin; Guide to buying a summerhouse; Discover the cabin; How to run electricity to a shed
- Dunster House: Log cabin buyers guide; Log cabins
- Planning Portal: Outbuildings: planning permission; Is building regulations approval needed for an outbuilding?
- IET: Buried conduits and ducts
See also: choosing a shed, shed bases and planning permission.