Design guide

Home sauna design: the checklist from our 100+ projects

A good sauna is born on paper: 80% of the problems we fix in other people's saunas are design mistakes, not build mistakes. Here is the checklist our engineering runs before any timber is cut - use it even if you build with someone else.

Design guide · 9 min · 2026-08-18

Use it in order: each item depends on the one before. It's the same flow as our free 3D design - which hands you all of this done, in 5 working days.

1. Location: the 4 tests of the right spot

Ceiling: 2.1-2.3 m of finished height - anything more is kW wasted forever.
The wet path: sauna door to shower/tub in 5 steps or fewer, on non-slip flooring.
The back wall: the cabin needs one 'technical' face for wiring and ventilation.
Heat neighbours: keep it away from the climate-controlled wine cellar and the main electrical panel.

2. Sizing and people

Practical ruler: 60 cm of bench per seated person; a 1.9 m upper bench for whoever likes lying down (everyone does). A couple: 1.6 × 1.4 m solves it. A family of 4-6: a 2.0-2.4 m front. Above that, two bench levels are mandatory - stratified heat is half the pleasure.

3. Wiring (the item that fails inspections)

Heater at ~1 kW/m³: a 6 m³ cabin = 6 kW (add margin for glass).
A dedicated circuit with its own RCD and cable at the maker's gauge - not 'whatever was left'.
In a building: a load letter to the condominium BEFORE buying anything.
Light: indirect 12 V under the bench or behind the backrest; a common ceiling fixture dies in months.

4. Ventilation and vapour barrier

A low air inlet by the heater + a high outlet on the opposite wall - renewal without losing temperature.
Continuous aluminium foil behind the panelling, seams taped: the humidity dies there, not in your wall.
A 5-7 cm gap under the door: part of the system, not a defect.

5. Floor, weight and water

Porcelain tile or stone under the cabin (timber flooring rots first), a drain nearby if there's a tub, and the load math: a full tub weighs 500-1,200 kg - slab verified before, not after.