How much timber does a garden room take?
A 4 × 3 m garden room is framed in 4x2 (47 × 95 mm C24) studs, on 4x2 (47 × 95 mm C24) floor joists, under 6x2 (47 × 145 mm C24) roof joists. Below is every piece in it, at 400 mm centres and at 600 — counted off the frame, not a rule of thumb.
Garden room materials list, 4 × 3 m
One card per supplier, each order packed into the lengths they hold, with the offcut named. This is the panel itself, not a picture of it.
Timber
209 lengths · 41 boards · 11 items
One order at a timber merchant, off the shelf.
| Stage | Material | Cut from | Buy | |
|---|---|---|---|---|
| Floor | 20 × 4.2 m | 20 | ||
| Floor | 11 × 2.4×0.6 m board | 11 | ||
| Walls | 32 × 4.8 m | 32 | ||
| Walls | 3 × 2.4 m | 3 | ||
| Walls | 2 × 3 m | 2 | ||
| Walls | 44 × 3 m | 44 | ||
| Walls | 39 × 4.2 m40 × 3.6 m | 79 | ||
| Walls | 15 × 2.4×1.2 m board | 15 | ||
| Roof | 5 × 4.8 m14 × 3.6 m | 19 | ||
| Roof | 10 × 4.8 m | 10 | ||
| Roof | 15 × 2.4×0.6 m board | 15 |
Estimates to help you plan, price up and build it yourself. If you’re unsure about a size, check it before you order.
The same garden room at 600 mm centres
The same garden room with the studs and joists 600 mm apart instead of 400. Fewer sticks — and a deeper roof joist, because it now spans further between them.
Timber
191 lengths · 41 boards · 11 items
One order at a timber merchant, off the shelf.
| Stage | Material | Cut from | Buy | |
|---|---|---|---|---|
| Floor | 19 × 4.2 m | 19 | ||
| Floor | 11 × 2.4×0.6 m board | 11 | ||
| Walls | 28 × 4.8 m | 28 | ||
| Walls | 3 × 2.4 m | 3 | ||
| Walls | 2 × 3 m | 2 | ||
| Walls | 36 × 3 m | 36 | ||
| Walls | 39 × 4.2 m40 × 3.6 m | 79 | ||
| Walls | 15 × 2.4×1.2 m board | 15 | ||
| Roof | 4 × 4.8 m10 × 4.2 m | 14 | ||
| Roof | 10 × 4.8 m | 10 | ||
| Roof | 15 × 2.4×0.6 m board | 15 |
Estimates to help you plan, price up and build it yourself. If you’re unsure about a size, check it before you order.
A 5 × 3 m garden room
The same build, a metre wider across the front.
Timber
235 lengths · 46 boards · 11 items
One order at a timber merchant, off the shelf.
Some pieces come jointed. Each one arrives in two, and the extra length is already in the order. Each line below names the section it is cut from — if your merchant carries a longer length, tick it on that row and the joint goes.
4x2 — 2 × floor rim board, 1 × sole plate, longer than the 4800 mm length you picked. Butt the two ends over a stud or a joist, and fix both pieces to it.
4x2 — 2 × head plate, longer than the 4800 mm length you picked. Butt the joint over a stud, then screw a piece of the same section across the face, cut from an offcut. That piece is not counted.
Western red cedar 145x20 TGV cladding board — 21 × cladding board, longer than the 4800 mm length you picked. Butt the two ends on a doubled batten, one batten for each end, with an 8 mm gap. Seal the cut ends, and don't joint the next course on the same batten. The second batten comes from an offcut and isn't counted.
Western red cedar 145x20 TGV cladding board — 5 × soffit, longer than the 4800 mm length you picked. Butt the two ends over a stud or a joist, and fix both pieces to it.
6x2 — 2 × roof edge beam, longer than the 4800 mm length you picked. Butt the two ends over a stud or a joist, and fix both pieces to it.
| Stage | Material | Cut from | Buy | |
|---|---|---|---|---|
| Floor | 22 × 4.8 m | 22 | ||
| Floor | 13 × 2.4×0.6 m board | 13 | ||
| Walls | 37 × 4.8 m | 37 | ||
| Walls | 3 × 2.4 m | 3 | ||
| Walls | 2 × 3 m | 2 | ||
| Walls | 51 × 3 m | 51 | ||
| Walls | 85 × 4.2 m | 85 | ||
| Walls | 16 × 2.4×1.2 m board | 16 | ||
| Roof | 24 × 3.6 m | 24 | ||
| Roof | 11 × 4.8 m | 11 | ||
| Roof | 17 × 2.4×0.6 m board | 17 |
Estimates to help you plan, price up and build it yourself. If you’re unsure about a size, check it before you order.
Your garden room, not this one
These three are round numbers. The designer works out the same list for whatever size you give it, with your doors and windows where you want them — and again the moment you move one. The design needs no account. Save it to get the list.
Design your ownA set-out drawing for construction on site. Not a structural calculation, and not prepared for planning or building control.