Cube Sauna UK: Modern Glass-Front Garden Sauna Guide & Prices (2026)
By Sarb Gill, BSc Biology — Founder, Steam & Oak. Last updated June 2026.
Cube saunas are the modern face of the outdoor sauna — flat-roofed, clean-lined, and usually fronted with a big pane of glass that turns your garden into part of the experience. If you want a sauna that looks like a piece of contemporary garden architecture rather than a traditional cabin, this is the format. This guide covers what sets a cube apart, the all-important glass, the build, your heat options, and real 2026 prices. It sits under our wider Outdoor Sauna UK guide — start there if you're still choosing between cube, barrel, cabin and pod.
Contents
- Why choose a cube sauna
- What makes a cube sauna different
- The glass front: what to know
- Thermowood and the flat roof: judging the build
- What size do you need?
- Heat options: electric, wood-fired or gas
- What to check before you buy a cube
- Cube vs barrel vs cabin
- Cube saunas in our range
- What cube saunas cost in 2026
- Base, placement and running costs
- Common cube sauna mistakes
- FAQ
- Final recommendations
1. Why choose a cube sauna
People choose a cube sauna for one main reason: the look. The flat roof, square lines and large glass front make it a genuine design statement — a modern structure that complements contemporary homes and gardens rather than the rustic, cabin-in-the-woods aesthetic of a barrel. Beyond the styling, the square shape gives generous headroom and a roomy, lounge-like interior, and the glass front frames your garden while you sweat. If aesthetics matter as much as function, the cube is the format to look at. Browse the range at Outdoor Cube Saunas.
2. What makes a cube sauna different
- Glass front. A large panoramic window (sometimes a full glass wall) is the cube's signature — it brings light in and makes the garden part of the session.
- Flat roof and square lines. The contemporary silhouette suits modern homes; it reads as garden architecture, not a shed.
- Headroom and space. The square cross-section gives more standing height and a roomier feel than a curved barrel of similar capacity.
- Premium build. Cubes are typically built in heat-treated Thermowood with quality glazing, which is part of why they sit at the premium end.
The trade-off versus a barrel is cost and heat-up: a square cube has more air volume to heat than a barrel of the same seating, and the glass is a heat-loss point, so cubes generally cost a little more to buy and run. You're paying for the design and the space — which is exactly why the glass quality matters so much.
3. The glass front: what to know
The glass is the whole point of a cube — and it's where quality differences hide, because a large pane is both the best and the most demanding part of the design. What to understand:
It must be toughened safety glass. A sauna door and front take heat, cold and the occasional knock, so the glazing should be toughened (tempered) safety glass — non-negotiable for safety and durability. This is standard on a quality cube.
Single vs double glazing. A big glass panel is the main heat-loss point of a cube. Better cubes use thermally efficient or double glazing with good seals to limit that loss — which keeps the sauna hotter, more even, and cheaper to run than a single-glazed pane that bleeds heat. If running cost or holding temperature matters to you, ask about the glazing spec.
Seals and frame. Heat is only kept in if the glass is sealed well into the frame; good sealing around the glazing is as important as the glass itself.
Orientation — view and privacy. Because the front is glass, which way it faces is a real decision: orient it to your best garden view, but also think about privacy and which way you're overlooked. The glass is the feature; point it well.
None of this should put you off — a well-glazed cube performs beautifully. It's simply that "big glass front" covers everything from a quality double-glazed panel to a cheap single sheet, and the difference shows up in comfort and your energy bill.
4. Thermowood and the flat roof: judging the build
Two more things define cube quality beyond the glass:
Thermowood. Most quality cubes are built in heat-treated (Thermowood) timber — more dimensionally stable and weather-resistant than untreated softwood, which matters for a flat-roofed structure standing in the British weather. It's a key reason cubes last well outdoors.
The flat roof. A cube's flat (or near-flat) roof is part of the look, but flat roofs need proper weatherproofing and a slight fall or covering so water runs off rather than pooling — a quality cube handles this; a cheap one can let water sit. Combined with a good base (section 11) keeping the structure level and off wet ground, that's what gives a cube a long outdoor life.
5. What size do you need?
Quoted capacity assumes upright seating; for relaxed use, the comfortable number is one below the headline. A Cube 160 (quoted 2-person) suits a couple with room to recline; a Cube 210 (4-person) is the sweet spot for most gardens — real room and the full glass-front effect without the largest footprint; a Cube 250 (6-person) suits larger groups. Buy for your realistic use plus a little — a bigger cube has more air (and more glass) to heat.
6. Heat options: electric, wood-fired or gas
Like our other outdoor saunas, cubes offer a choice of heat:
| Heat source | Best for |
|---|---|
| Electric | Convenience and clean lines — most cubes pair with a quality electric heater; needs a garden power supply |
| Wood-fired | The authentic ritual, no electrics — available on some cube models |
| Gas (LPG) | Quick heat without mains electricity — our gas-ready cubes suit off-grid spots |
Most premium cubes (like the Hekla range) ship with a sized electric Harvia heater for a clean, set-and-forget setup that complements the minimalist look. We also build gas-ready cubes with electric or wood-fired options — for example the Gas Cube 2.4m with Porch from £4,695. For the heat-source running-cost comparison, see How Much Does a Sauna Cost to Run?, and for the gas case, Gas Saunas Explained.
7. What to check before you buy a cube
- Is the glass toughened safety glass, and single or double glazed? Double/thermally-efficient glazing holds heat and cuts running cost; ask the spec.
- Is it Thermowood? Heat-treated timber lasts far better outdoors than untreated softwood.
- How is the flat roof weatherproofed? A proper covering and fall so water runs off, not pools.
- Is a heater included and sized to the cube? Premium cubes ship with a matched heater; check it's the right output for the volume.
- What's the warranty, and does it cover the cabin, the heater and the glass?
8. Cube vs barrel vs cabin
If you're weighing the cube against the other outdoor formats, here's the honest trade-off. A barrel is better value and heats more efficiently — its curved shape has less air to heat — so it's the choice if value and quick warm-up matter most. A cabin gives the most room and the most traditional, room-like Finnish feel. A cube sits between them on price but wins on modern design, the glass-front view and headroom, at a slightly higher running cost than a barrel because of the glass and square volume. Choose a barrel for value and efficiency, a cabin for space and tradition, a cube for design and light.
9. Cube saunas in our range
Hekla Cube range — the premium glass-front cubes, Thermowood-built with Harvia heaters included: Cube 160 (2-person) £6,499, Cube 210 (4-person) £6,999, and the 6-person Cube 250.
Gas-ready cubes — our Steam & Oak cubes with electric or wood-fired options, a more affordable route into the cube look: from £4,195 for the 1.8m Gas Cube up to the 3.4m Premium L-Bench. Ideal if you want the modern design without the top-end price.
10. What cube saunas cost in 2026
| Budget | What you get | Example |
|---|---|---|
| £4,195 – £5,200 | Gas-ready cubes, electric or wood-fired | Gas Cube 1.8m £4,195, 2.4m £4,695 |
| £6,499 – £6,999 | Premium Hekla glass-front, heater included | Cube 160 £6,499, Cube 210 £6,999 |
| £7,499 – £8,299 | Large premium 6-person cubes | Cube 250 £7,499–£8,299 |
So a cube sauna runs from £4,195 for a gas-ready model to around £8,299 for a large premium 6-person, with the premium 2–4 person Hekla cubes — heater included — at £6,499–£6,999. Budget separately for the base and, if electric, an electrician.
11. Base, placement and running costs
A cube needs a level, load-bearing, well-drained base and a clear delivery route — the same outdoor essentials covered in detail in the Outdoor Sauna UK guide. Two cube-specific points: position it to make the most of the view through the glass front (and your privacy), and shelter it from the worst of the wind, which — combined with good glazing — helps running cost. A cube takes a little longer to reach temperature than a compact barrel because of the larger air volume and the glass, but quality double glazing narrows the gap. Running costs by heat source are broken down in How Much Does a Sauna Cost to Run?
Our construction service — the insulating-paste difference
Outdoor saunas arrive flat-packed, and we offer a construction service from £500 (by-the-mile beyond a certain distance — send your postcode for a quote). What sets our builds apart is the insulating paste we apply between every panel as we construct it. Gaps between panels are the most common reason a sauna never quite gets hot enough or bleeds heat — we've been called out to re-fit saunas a previous installer left full of gaps. Our builds take a little longer because of the paste, but your sauna seals tight, reaches a proper heat, and holds it far better, which means a better session and lower running costs over its life. See our sauna installation FAQs for the detail.
12. Common cube sauna mistakes
1. Underspecifying the glazing. A big single-glazed pane loses heat and costs more to run. Look for toughened, thermally efficient glass and good seals.
2. Skipping the base. A flat-roofed cube needs a properly level base — uneven ground stresses the frame and the door/glass alignment.
3. Facing the glass the wrong way. The front is the whole point — orient it to your best garden view and your privacy, not just whatever's easiest.
4. Ignoring the flat roof. Flat roofs need proper weatherproofing and run-off; check it's done well so water doesn't pool.
5. Forgetting the electrician (electric models). A garden circuit isn't in the price — or choose a gas-ready cube to avoid it.
13. FAQ
What is a cube sauna?
A cube sauna is a modern outdoor sauna with a flat roof, square lines and usually a large glass front. It's the contemporary alternative to a traditional barrel or cabin, offering a design-led look, generous headroom and a panoramic view of the garden, typically built in heat-treated Thermowood.
Are glass-front cube saunas cold or energy efficient?
A quality cube with toughened, thermally efficient (ideally double) glazing and good seals holds heat well and runs efficiently — the glass is the main heat-loss point, so the glazing spec is what matters. A cheap single-glazed pane loses more heat and costs more to run, which is why it's worth asking about the glazing before buying.
How much does a cube sauna cost in the UK?
In 2026, cube saunas start around £4,195 for a gas-ready model and £6,499 for a premium glass-front Hekla cube with heater included. Large 6-person premium cubes reach around £7,499–£8,299. Budget separately for a base and, for electric models, an electrician.
How long does a cube sauna take to heat up?
A cube takes a little longer than a compact barrel because of its larger air volume and the glass front — typically around 30–45 minutes from cold for an electric cube. Quality double glazing and a sheltered position narrow the gap and help it hold temperature.
Cube or barrel sauna — which is better?
It depends on priorities. A barrel is better value and heats more efficiently thanks to its curved shape; a cube offers a modern design, a glass front, more headroom and a premium feel, at a somewhat higher price and running cost. Choose a barrel for value and efficiency, a cube for design and space.
Do cube saunas need a base?
Yes. A cube needs a level, load-bearing, well-drained base — paving slabs, a concrete pad or a proper timber deck. A level base is especially important for a flat-roofed cube to keep the frame square and the door and glass aligned, and to protect the structure.
How long does a cube sauna last?
A quality cube built in Thermowood with toughened glazing and a properly weatherproofed flat roof, on a good base, lasts many years outdoors. Thermowood's stability and weather resistance, plus keeping the structure level and off wet ground, are the main factors in longevity.
14. Final recommendations
For the full premium cube experience with the heater included, the Hekla Cube 210 (4-person, £6,999) is the sweet spot; step down to the Cube 160 for couples or up to the Cube 250 for groups. Want the modern look for less? Our gas-ready cubes start at £4,195 with electric or wood-fired options.
Whichever you choose, get the glazing, base and heat source right. Browse the full range at Outdoor Cube Saunas, compare formats in the Outdoor Sauna UK guide (or weigh it against a barrel or cabin), or message us with your garden and we'll point you to the right cube.