Sauna Buying Guide

Our garden saunas can be heated either way, and it is a genuine choice rather than a budget one.

Harvia Cilindro (electric). A sculptural free-standing column heater whose steel basket holds a generous bed of stones, radiating heat from every side. Ready to bathe in 30 to 45 minutes, with precise temperature control and no fuel or flue to manage. Available at 6.8 kW and 9 kW.

Harvia Linear 18 (wood-fired). A 14.3 kW wood-burning stove for the traditional experience, with a deep enveloping heat no electric heater quite matches. It needs no power supply for heat, so it suits gardens beyond a convenient electrical run.

Both reach full loyly temperature. The honest summary is convenience against authenticity. Wood means storing fuel, lighting it around 45 minutes ahead, and clearing ash.

Indoor traditional cabins use the Harvia The Wall, a slim wall-mounted electric heater. Output follows cabin size:

• Traditional 160 (2 to 3 people): 6 kW or 9 kW
• Traditional 210 (3 to 4 people): 9 kW
• Traditional 210x (4 to 5 people): 9 kW
• Traditional 220 (5 to 6 people): 9 kW

More kilowatts does not mean a better sauna, it means a bigger room brought to temperature in a sensible time. Undersize the heater and it labours and never holds heat with a full bench. Oversize it in a small cabin and you gain nothing but a larger bill. On the smallest cabin, 6 kW is the sensible default and 9 kW gives faster heat-up.

This is the most overlooked decision on the page, and on our outdoor electric heaters it changes what the sauna can actually do.

• Manual (Cilindro PC90). A dial and timer on the heater itself. Simple and dependable, but it reaches a milder 60 to 70°C, so it suits gentler bathing rather than full Finnish heat.
• Digital plus Wi-Fi (Cilindro PC90XW). Heats to a full 110°C and includes the Harvia Fenix Wi-Fi control panel. This is the option we recommend and the one most customers choose.
• Digital (The Wall, indoor). Our indoor heaters come with digital control as standard, with Wi-Fi scheduling available through the Fenix panel.

If you want full-heat traditional bathing, choose a digital option. The manual heater is a fine thing, but its temperature ceiling is a real limit rather than a detail.

The Fenix is a 4.3 inch glass touchscreen that replaces the heater’s own controls, and it changes how you use a sauna day to day. You start it from your phone on the way home rather than remembering to walk out and switch it on.

• Remote start, scheduling and monitoring through the MyHarvia app
• Temperature from 30 to 110°C, plus humidity, lighting and ventilation control
• Three customisable presets and a smart timer
• Learns how your heater performs to reach temperature efficiently
• Wall-mounted, so it can sit in the sauna, the bathroom or the living space

Wood-fired saunas are controlled the traditional way, by how you build and feed the fire. There is no thermostat, which is either the appeal or the drawback depending on your temperament.

For garden saunas the base must be prepared before build day, and must be flat, level, solid and permanent. A concrete slab is ideal, and reinforced patio or paving over a solid sub-base also works.

Grass, gravel, soil and any soft ground are not suitable. An uneven base compromises the structure and prevents correct alignment during the build, and base problems can affect your warranty. This is the single most common reason a build gets delayed.

Allow one metre of clear space on all sides of the footprint so our technicians can assemble the sauna. Typical footprints:

• Cube 160: 1570 x 2250 mm
• Cube 210: 2250 x 2070 mm
• Cube 250: 2280 x 2470 mm
• Barrel 210: 2070 x 2250 mm
• Barrel 250: 2470 x 2250 mm

You will also need a clear access route at least one metre wide, with no obstructions such as furniture, fences or plants, and nothing overhead in the way such as branches, cables or rooflines.

Our build team assembles the structure, roof, waterproof membrane and shingles, and finishes the exterior. They do not carry out electrical work. Your electrician handles:

• Drilling a suitable cable entry point
• Installing and connecting the heater
• Connecting lighting and controls
• Ensuring the work meets local regulations, then testing and certifying it

Plan this with a qualified electrician before your build is booked, so the sauna is not left finished but unusable. One last thing people forget: the sauna stones must be washed and fully dried before first use. Full detail is in our pre-delivery and build guide.

Running cost comes down to heater output, how long you heat for and how often. Infrared costs least per session because it warms you rather than the whole room and is ready in minutes. A 9 kW traditional cabin costs more per session but delivers heat infrared cannot.

We break the numbers down by heater type and size in our guide to how much a sauna costs to run.

Most garden saunas fall under permitted development in the UK, but it depends on size, height, siting and whether your property has restrictions such as a conservation area or a listed building. Check with your local planning authority before you order.

Our indoor Traditional models are quick-build and most assemble in a few hours, and our infrared cabins are plug-and-play. Outdoor saunas are built on site by our own trained team, which is included. In every case the electrical connection must be completed by a qualified electrician and is not part of the build.

Use the options listed on the model you are looking at, as they are already matched to that cabin. On the smallest indoor cabin, 6 kW is the sensible default and 9 kW gives faster heat-up. Outdoors, choose a digital or Wi-Fi option if you want full 110°C heat.

Yes, honestly. You store and carry fuel, light it around 45 minutes before bathing, and clear out ash. For many people that ritual is exactly the point. If it sounds like a chore, choose electric.

Around 30 to 45 minutes for a traditional electric sauna, similar or a little longer for wood-fired, and 10 to 15 minutes for infrared. With the Fenix Wi-Fi panel you can start an electric heater remotely so it is ready when you are.

Choose traditional for the authentic high-heat ritual and loyly steam. Choose infrared for gentler warmth, faster warm-up, longer sessions and no electrical work. Our guide to infrared vs traditional saunas compares them properly.