What the calculator counts
- Walls and ceiling: studs, plates and ceiling joists at your spacing, mineral wool, aluminium foil with 15 % extra for overlaps, and foil tape. Switch off the framing when you line existing walls.
- Inside finish: battens for the air gap behind the panelling, tongue-and-groove panelling with the number of boards for your board size, and the floor.
- Benches: bench boards and the bench frame, from the number of tiers and the layout.
- Heater and fit-out: the heater output from our catalog for the room's effective volume, stones, a guard rail, the door, the window, vents, a light, a thermometer and the electrician.
- Outdoor cabins also get cladding, a wind barrier, the roof, rafters, floor joists, floor insulation, floor boards and foundation points. Barrel kits come with walls and benches, so they get the fit-out and the base.
How the quantities are worked out
| item | rule |
|---|---|
| Panelling | walls + ceiling, minus the door and window, plus the extra for cuts (10 % by default) |
| Boards | panelling area ÷ visible board width, then ÷ board length |
| Foil | walls + ceiling + 15 % for overlaps and corners |
| Studs and battens | one per spacing along each wall, plus one at each end and beside openings |
| Bench boards | 10 m of 90 mm board per m² of bench (10 mm gaps) + 15 % |
| Outdoor walls | 85 mm of layers outside the insulation: battens, wind barrier, cladding |
| Roof | outer footprint + 300 mm overhang all round; gable roofs at 25° |
| Foundation | blocks or ground screws on a grid no wider than 1.5 m |
The quantities are for buying, not a cutting plan. Round up to the pack sizes your shop sells.
Pricing your list
Type the price per unit from your shop into each line: per square metre (or square foot), per metre (or foot), per kilogram, or each. The total updates as you go, and the prices stay in your browser for next time. The heater line shows the list prices of the heaters in our catalog that are rated for your room, with the shop and the date we saw them, and can fill in their median for you.
What is not included
Labour, delivery, permits, screws and nails, sealants, tile adhesive, tools, and the electrical materials, which come with the electrician's quote. A wood stove's chimney depends on your roof and the stove's manual. For the order of the work, see how to build a sauna; for kit and heater prices, see how much a sauna costs.