How to design a sauna – a comprehensive guide

Harvia saunaremontti

What are the things that you should and need to take into account when you start planning a sauna renovation? We put together an information pack to help you with all stages of sauna renovation. In this article, we give you tips for designing space arrangements and surface materials, inspecting the structures, selecting and maintaining the construction and surface materials, and enhancing the sauna experience. 

There are alternative options available for different needs and preferences. Our sauna designers are happy to help you – do not hesitate to contact us!

First steps in design

A sauna renovation starts with a dream: think about what your perfect sauna would be like, what would it look and feel like, and what kind of functionalities it would have. If you need new inspiration, you can use Harvia’s abundant inspiration bank and learn more about our interior design range: https://harvia.fi/en/products/sauna-interior/

When you have found a picture of the sauna of your dreams, you can take up a tape measure. Measure the width, height and depth of your sauna as well as the window and door openings. Also measure the log, stone and window surfaces that affect the heating power requirements; it will help professionals choose a sauna heater with the right amount of power for your sauna. You can also use Harvia’s sauna calculator to determine what size heater suits your sauna best.

You can create the exact design you want with Harvia’s Sauna Designer -tool online and request a quote, or make a list of your own ideas and contact a Harvia sauna designer directly for design assistance, free of charge.

Jarvian Saunasuunniteluohjelma HSD

Permits and structures

As a rule, renovating a sauna in a detached house does not require a building permit or an action notification. A permit is only necessary for demolishing or building a load-bearing structure and expanding a bathroom. A permit is also needed for building a completely new bathroom or sauna. In that case, contact the building control services of your own home municipality.

If you live in a housing company, you must notify the board of directors of the housing company about the renovation. Typically, housing companies require that the waterproofing and electrical work be carried out by a professional. Therefore, you should only start the demolition after you have made sure that the permits are in order.

Demolishing an old sauna

When demolishing an old sauna, it is important to check the structures that are revealed from under the surface and repair them, if necessary, before installing new surfaces. The aluminium paper must be intact and leak-proof. If the paper is damaged, check if there is any damage behind the paper, too. If everything is all right, you can start installing new surfaces.

Glass walls have become more popular at renovation sites, and they can be installed depending on the structures of the wall with the door. A professional must assess the possibility of installing a glass wall at the demolition stage. Installing additional support for the existing wall may be necessary.

Updating the building solutions to modern times

In the last few decades, construction technology has developed by leaps and bounds, and new kinds of construction solutions and materials have become available to replace old ones. Even though things like urethane-based insulation materials have been available for a long time, they were not used in saunas built 20–30 years ago.

The benefit of urethane sheets as insulation is their thinness. A urethane sheet of 30 mm corresponds to 80 mm of mineral wool insulation. Replacing the insulation can save 5 cm in wall thickness in small spaces. Waterproofing products have also developed a great deal in recent years, reducing the risk of water damage considerably.

By the way, you should note that if you replace a woodburning stove with an electric sauna heater, the old masonry flue cannot be panelled shut or benches installed on top of it if the flue is still in use. There is often a fireplace, an iron stove or similar on the other side of the wall, connected to the same flue. The masonry can be tiled over, but nothing can be attached to it. You should check the issue with the fire authority in your own area.

Kiukaan kierrätysohje

Electrical installations in a sauna renovation

The electrical work in a sauna must always be done by a professional. This means that you should contact an expert electrical designer well in advance when you are planning the electrical work in your sauna. In most cases, there is no point in changing the location of the sauna heater during the sauna renovation, but with an electric sauna heater it is usually possible, if desired.

Changes to the electrical wiring should be planned at a very early stage of the renovation. The supply current cables are installed in the wall insulation, which means that the issue needs to be taken into account already during the demolition stage. When the surfaces are being installed, it will be too late to change the electrification.

Choosing benches and surface materials

In sauna design, you need to consider how many people will be using the sauna at the same time and how often. The seat for one person is usually 60 cm in width.

If you want to have as many seats as possible in the sauna and the space is fairly small, a simple straight bench is usually the best solution. If you try to install a corner bench or even a U-shaped bench in a small sauna, the end result may feel cramped and uncomfortable to use. This means that you need to be realistic and consider the space when choosing the bench model.

Of course, you can always install things like benches for two people to lie down and relax even in a small space.

Harvia Sauna

For the material, you can choose between several different woods: golden yellow abachi, reddish brown alder, light-coloured aspen or dark, heat-treated aspen. There is also a rich combination of pale-coloured spruce and black colour available for benches. Harvia uses only sustainably produced wood in making saunas. https://harvia.fi/en/harvia-uses-sustainably-sourced-wood-in-sauna-production/

You can let your imagination run free when designing the wall surfaces! In addition to traditional panelling, you can add character to the walls with different kinds of stone. An increasingly more common option is also to replace the front wall of the sauna with a glass wall, which brings spaciousness and a modern feel to the area.

You can use the shapes, colours and installation methods of the panelling boards to create the atmosphere you want in the sauna. You can choose spruce, pine, aspen, heat-treated aspen, heat-treated brushed alder, alder or smoke sauna panelling boards as the panelling material. Learn more about Harvia’s different panelling boards: https://harvia.fi/en/model/panelling-boards/

Harvia Formula Lauteet ja saunan valaistus

Bench maintenance

In addition to ease of use, ease of maintenance is also an important feature of benches. For example, removable bench covers make cleaning and maintenance much easier. Most of Harvia’s benches can be removed easily for cleaning. Separate benches and frames also make sauna installation easier.

Sauna surface treatments have developed a great deal in recent years. In fact, various kinds of coloured surface treatments have become mainstream, and thanks to them, Finnish saunas no longer look like they came out of the same assembly line. A wax treatment makes the surfaces any shade from dark or bright white to tones of grey or brown – whichever you choose!

In bench maintenance, paraffin oil treatment offers excellent protection and we recommend it for everyone who is thinking about replacing benches. The paraffin is impregnated into the wood, protecting the bench from moisture damage and embedded dirt. The paraffin is completely non-toxic and food-grade. The oil wears out and evaporates during use, which means that the benches need to be treated again once or twice per year, depending on how often the sauna is used.

Adding to the sauna experience 

You can create a mood and atmosphere in the sauna in many ways. The placement of wall panels, the choice of wood, surface treatments and indirect LED or coloured lighting create a unique feel. If you want to take your sauna experience to the next level, there are plenty of options available.

Hybrid saunas are becoming more and more common. It means that in addition to an electric sauna heater or woodburning stove, the sauna is also equipped with one or more infrared heaters. The infrared heaters are installed behind the upper bench. They are intended to warm up the person sitting in the seat in question, not the whole sauna room.

  • The infrared heater warms you up from the inside, penetrating deeper into the skin tissue to up to 5 cm.
  • You can go warm up in front of the infrared heater while bathing in the sauna, for instance, or simply sit there in your ordinary clothes on a chilly autumn day.
  • You can also use the sauna and the infrared heater at the same time; the sauna temperature must not exceed 70 degrees Celsius, however.
  • Infrared saunas offer the same health benefits as a traditional sauna: they have also been found to expand peripheral blood vessels and relieve pain as a result.

Harvia Hybridisauna Scala Forte Infrapunasauna

With an automated water dispenser, you can lie down and enjoy the humid heat simply with the press of a button. The automated water dispenser operates either automatically at specific intervals, or by pressing a button. You can also add your favourite sauna fragrance to the dispenser.

A Sauna Steamer is an excellent accessory for those who love bathing in a very humid and steamy sauna. The steamer is an add-on device that works independently along with an electric heater to make the sauna experience more gentle and humid. The gently humid steam promotes beauty and health, as it opens your airways, makes your skin beautiful and relaxes your body and mind.

Instead of a traditional sauna, you can also install a completely steam-based steam sauna at your home.

You can add a nice atmosphere to the sauna by playing music. Install loudspeakers to the sauna and play your favourite music or nature sounds by connecting them to your mobile phone, for example.

Another way to add easy luxury to your sauna use is to use remote control, which makes it possible to set your sauna with a mobile phone to be ready for bathing at exactly the right time. What could be better than to go into a hot sauna straight from a jog?

An alternative or an addition to your own traditional sauna is a room heated completely with infrared. Infrared cabins make it possible to enjoy a pampering moment of relaxation at every home.