Planning an outdoor sauna: site, foundation, permits and power
A garden or cabin sauna is a small building, not a piece of furniture. A little planning before you choose a model saves time, cost and surprises later. This guide covers the questions we ask every customer.
1. Start with how you will use it
How many people will usually bathe together? Do you want somewhere to change, to rest between rounds, or to spend the whole afternoon? The answer decides the size more than the garden does.
- 5–9 m²: sauna only – compact, for one to a few people.
- 12–15 m²: sauna with a changing area.
- 18–28 m²: sauna with a resting space or lounge.
- 34–40 m²: a complete wellness setting with lounge and shower area.
2. Choose the site
Point the glass at the view you want – water, forest or open landscape – and away from neighbours and the street. Evening sun from the west is a favourite, but think about privacy after dark when the sauna is lit.
Keep the walk from the house short and sheltered, and plan where you will cool off: a shower, a plunge pool or the lake.
3. Check delivery access early
Modular saunas arrive largely finished and are lifted into place. Before ordering, confirm that a lorry and crane can reach the site.
- Width and firmness of the access road or driveway.
- Overhead lines, trees and buildings in the lifting zone.
- Where the crane can stand, and how far it must reach.
- Slopes, soft ground and seasonal restrictions.
4. Foundation
The sauna needs a level, load-bearing and well-drained base. Common solutions are a concrete slab, point or strip foundations, or ground screws. The right choice depends on the soil, frost depth, slope and the weight of the chosen model, so it should be confirmed for your site before installation.
5. Permits and local rules
Rules differ between countries and often between municipalities. Many places allow small garden buildings without a full building permit within limits for size, height and distance to the boundary – but a sauna with a heater, electrical installation or a chimney may be treated differently, and protected areas, coastlines and heritage zones often have stricter rules.
Contact your local building authority early with the model’s footprint, height and planned position. We provide drawings and dimensions to support that conversation. This guide is general information, not legal advice.
6. Power and heater
Most electric sauna heaters need a dedicated circuit, and larger heaters usually need a three-phase supply. Plan the cable route from the house and use a licensed electrician for the connection. A wood-fired heater needs a chimney solution and must meet local fire-safety rules. The heater is selected for the final room volume and glazing.
7. Water and drainage
Models with a shower need a water supply, drainage and frost protection if the sauna will be used in winter. Where there is no water connection, an outdoor shower or a plunge by the water can be the simpler choice.
8. Budget beyond the sauna
When comparing offers, check what is included. Besides the sauna itself, allow for:
- Groundwork and foundation.
- Transport, crane and installation.
- Electrician and cable route.
- Water and drainage, where relevant.
- Decking, steps, lighting and landscaping.
- Permit fees, where relevant.
9. From idea to order
Send us a short description and a few photos of the site. We suggest a suitable model, check access and the practical questions, and prepare a written quotation with specification, delivery and installation. Nothing is binding until you accept the quotation.
Ready to plan yours?
Tell us about your site and how you want to use the sauna.