Bathhouses
Designing a bathhouse: what to get right the first time
A Russian bathhouse usually gets rebuilt not because of the stove or the log walls, but because four things were skipped at the planning stage: ventilation, drainage, stove clearances and the ceiling height in the steam room. Each takes an hour to fix on paper and tens of thousands of roubles to fix in a finished building — and ventilation sometimes cannot be fixed at all.
Here is what a bathhouse project consists of, which dimensions actually work, where the mandatory clearances run, and what it all costs.
What a bathhouse is made of
The minimum working set is four rooms, and none of them can be dropped without a penalty:
| Room | Area | Why |
|---|---|---|
| Porch or veranda | 2–4 m² | Cuts off cold air in winter. Without it the heat leaves through the door |
| Lounge | 12–20 m² | This is where people actually spend their time, not in the steam room |
| Washroom | 4–6 m² | Shower, sometimes a plunge pool. Merging it with the steam room is a bad idea |
| Steam room | 6–9 m² | Sized by the number of people, not by "bigger is better" |
If the budget allows: a WC (otherwise guests walk to the house), a plant room for the tank and electrics, and a terrace off the lounge.
For an example of how this comes together, see a bathhouse with a lounge — a full set including electrics and plumbing.
Steam room size: count people, not square metres
One person seated needs 0.7–0.9 m² of bench; lying down, 2 m of length. That gives a simple rule:
- two or three people — 2.0 × 2.4 m at 2.1–2.2 m high;
- four or five — 2.4 × 3.0 m;
- a lying bench needs a wall at least 2.2 m long, with room for your feet.
The ceiling belongs at 2.1–2.3 m, and that is physics rather than economy. Steam collects under the ceiling in layers; the higher the ceiling, the more volume to heat and the harder the right regime is to catch. A 2.7 m ceiling in a steam room means more firewood and a permanent fight with ventilation.
The bench sits 100–110 cm above the floor, with the upper bench higher than the top of the stove door — otherwise the steam never reaches the person lying on it.
The stove: clearances you cannot shorten
Half of all rebuilds happen here. The essentials:
- Clearance to combustible construction — 50 cm unprotected, 38 cm with a protected wall (sheet metal over basalt board with an air gap). A metal stove against a timber wall with no protection is the most common mistake.
- A separate foundation for the stove, not tied into the wall footings, for anything over 750 kg (a brick stove almost always is).
- The flue through the floor structure — a fire stop with a 25 cm clearance to combustibles, packed with non-combustible material.
- Flue height — at least 500 mm above the ridge if the flue is within 1.5 m of it; not below the ridge at 1.5–3 m.
- The floor in front of the firebox — a 50 × 70 cm metal sheet.
Firing the stove from the lounge or the porch through an extended firebox tunnel is better practice: no firewood, no mess and no oxygen draw inside the steam room.
Ventilation: the part most often forgotten
Without supply and extract, a steam room never airs out, the timber never dries, and within two or three seasons it develops a smell that nothing removes.
The scheme that works:
- Supply — a 100 × 150 mm opening behind the stove, 20–30 cm above the floor, so incoming cold air passes straight over the heater.
- Extract — the same size on the opposite wall, 30–40 cm above the floor, with a duct inside the wall running up to the roof.
- Dampers on both: closed while heating, slightly open while steaming, fully open afterwards to dry out.
A scheme with the extract under the ceiling works worse — it removes exactly the hot layer the whole thing is heated for.
Drying is a separate loop. The washroom needs a humidity-rated extract fan; otherwise the tiles and grout sit at a moisture level no sealant survives.
Drainage and waterproofing
The order that saves you from rebuilding the floor:
- a 2 % fall in the washroom screed towards a gully with a dry trap (a water trap dries out between visits and lets the smell through);
- applied tanking carried 20–30 cm up the walls — not "a sheet of plastic under the boards";
- a separate drain from the steam room, also with a fall: there is less water there, but there is water;
- discharge to a septic tank or a soakaway at least 20 m from any drinking well.
If the floor is timber, make the boards liftable and leave a ventilation gap beneath. A sealed timber floor rots within three or four years.
Materials: where to save and where not to
| Element | Sensible choice | Avoid |
|---|---|---|
| Steam room lining | Lime, aspen, cedar | Pine and spruce: resin bleeds when hot |
| Benches | Lime, abachi | Any timber with knots |
| Insulation | Foil-faced basalt wool | Polystyrene and any polymer |
| Vapour barrier | Foil on kraft, joints taped with foil tape | Ordinary plastic sheet |
| Internal fixings | Stainless, concealed | Galvanised, and any exposed heads — burns |
| Steam room door | Glass or lime with a timber handle | Metal handles |
Where to put it on the plot
Exact rules depend on the land use class and the local regulations, but the baseline is:
- at least 1 m to the boundary;
- 8–15 m to the neighbour's house, depending on the construction materials of both;
- no fire regulation applies to your own house, but 5–8 m is sensible: smoke and sparks should not reach the windows;
- at least 20 m to a well or borehole where waste discharges to ground.
Check the easements separately: gas, power lines, water protection zones near a river. That is done from the plot's planning certificate before design starts.
A bathhouse under 50 m² on a garden plot can usually be built without notification, but a permanent structure on foundations is worth registering — otherwise it cannot be insured or counted on resale.
What the design costs
| What you order | Price | What it includes |
|---|---|---|
| Layouts | from 10 000 ₽ | Options for your plot |
| Concept design | from 300 ₽/m² | Massing, layouts, siting, visualisation |
| Architecture + structure | from 800 ₽/m² | Plans, elevations, sections, details, foundation, rafters |
| Full set with services | from 1 470 ₽/m² | Plus electrics, plumbing, heating and ventilation |
For a 40 m² bathhouse the full set comes to roughly 60,000 ₽ — against the cost of rebuilding one floor with its waterproofing. Price it for your area on the services page.
Frequently asked
Can the washroom and steam room be combined?
In a building under 20 m² it sometimes has to be. But the steaming regime suffers: humidity after washing prevents proper steam, and the benches never dry. If the area allows, keep them apart.
Wood-fired or electric stove?
A wood stove gives the real regime and asks nothing of your electrical supply. An electric one is simpler — no flue, no firewood, switched on from your phone — but a heater for 6 m² needs 6–8 kW, which is half the capacity of a typical plot.
Does a bathhouse need a foundation?
Yes, usually piles with a grade beam or a shallow strip. The building is light but unevenly loaded: the stove is heavy and the log walls move. Sitting it on blocks without calculation ends with the steam room door jamming within two seasons.
Can it be attached to the house?
It can, and it is convenient in winter. The requirements are stricter: a fire wall between the two, separate ventilation, tanking along the junction. A proper set of drawings is essential here — humidity next to the timber structure of a house forgives very little.
How long does the design take?
Layouts, 3–5 days. Concept design, two weeks. A full set, three to four weeks. We work without days off and take urgent projects.
Let us design yours
Describe the plot, how many people will use it and your budget — we will propose a layout and price the work. See also other projects in the bathhouse section and our working documentation sets.