ICON 220 XL from the front corner, showing the full height glass front wall, the door set into it and the shingle roof wrapping over the curved stavesICON 220 XL straight on, the two level benches and the heater visible through the glass frontICON 220 XL from the side, 2,310mm long, with the shingle roof over 42mm thermo treated stavesICON 220 XL rear wall in 28mm tongue and groove thermo treated timberInside the ICON 220 XL, the two level benches along the side and the heater bay beside the glass doorCutaway of the ICON 220 XL from above showing the two level benches on both sides and the heater by the door

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ICON 220 XL: 4 Person Cube Sauna with Full Glass Front

Two decisions, the heater and the roof colour. Everything else is in the price.

From £7,620.00

4 people9kW heater includedKerbside delivery
Choose Open each row to choose. The price follows.
Heater Harvia Cilindro PC90, 9kW electric
Roof colour Not selected

Screen colour is a guide rather than a match, and timber grain moves the result either way.

Kerbside pallet delivery to mainland UK included

About 14 weeks from order. We confirm the current figure in writing when you order.

Warranties honoured properly Fair, clear returns
  • 9kW Harvia heater, its controls and 80kg of stones included
  • Painted at the factory, so it arrives finished
  • Kerbside pallet delivery to mainland UK included
Delivery & installation

Delivery to a mainland UK address is in the price. The cabin arrives as a flat pack kit on one pallet, 2.3m by 1.2m by 1.2m and about 900kg, on a lorry with a tail lift. The driver sets it down at the kerb or on the nearest firm, level, hard surface the pallet truck can reach; a pallet truck does not cross gravel, grass or a step, and at this weight the surface has to be hard standing rather than a lawn. From there the parts move by hand, and two people carry everything.

Offshore addresses, the Scottish Highlands and islands, and any address a lorry cannot reach are quoted separately before anything is ordered, and if the figure does not suit you the order is cancelled and refunded in full at that point.

Installation is not in the price. It is optional, from £650, and we quote it for your site and confirm the cost before anything is delivered. Tick it when you order or ask us about it afterwards; either way nothing is booked until you have agreed the figure.

Returns

Until the order is placed with the factory you can cancel and be refunded in full, with no reason needed. Your statutory cancellation rights are set out in full in our returns policy.

Check the pallet on the day it arrives, count the parts against the list in the manual, and tell us about anything damaged or missing within 48 hours with photographs. Anything that arrives damaged or faulty is ours to put right. Missing parts found later during assembly are not caught by that window, so report those as you find them, one list, with photographs, and do not book an electrician or an installer for a fixed date until the delivery has arrived and been checked.

About this product

A four person outdoor sauna in thermo treated timber, 2,260mm across and 2,310mm long, with the whole front wall in 8mm toughened bronze glass and the door set into it. It is the ICON 125's bigger brother: the same rounded cube, the same glass front, and a room that seats four on two levels of bench instead of three on one. It ships flat on a single pallet, 230cm long and about 900kg, which a tail lift lorry can set down on hard standing.

Why it is built without insulation

The sides and roof are 42mm solid staves and the back wall is 28mm tongue and groove. There is no insulation behind either, and that is the design rather than an economy. The mass of the timber is the insulation, which is how a stave built sauna works: it takes longer to bring up than an insulated cabin and it sheds heat faster once the heater is off. What you get in return is a cabin that behaves like a sauna rather than like a heated room, in a shape with no corners for heat to sit in.

Thermo treated timber only. Thermo treatment is kiln modification with heat and steam rather than chemicals; it raises dimensional stability and resistance to rot, which is what a timber cabin standing in a British garden through a wet January is actually up against. The outside is painted at the factory before it ships, so it arrives finished, and the bitumen shingle roof comes in four colours at no difference in price. The cabin weighs about 900kg as a kit; add the heater, the stones and four adults and the loaded figure is nearer 1,300kg, which is the number to design the base around.

The heater, and the only decision to make

Three heaters, all Harvia, all supplied with their stones. The maker's sheet puts the room at about 11 cubic metres, and a full glass wall asks more of a heater than a timber one, so the two electric heaters here are the 9kW columns rather than the 8kW wall heater fitted to the ICON 125. The wood burner sits toward the top of its published range for a room this size, which means allowing a little longer to come up on a cold evening.

Harvia Cilindro PC90, 9kW. Fitted as standard. A floor standing column rated for 8 to 14 cubic metres, holding 80kg of stones behind a steel mesh, with the timer and thermostat on the heater. It needs a dedicated circuit installed and certified by an electrician: 40 amps single phase in 10mm² cable, or 3 × 16A on three phase, and a room containing a sauna heater is a special location under Approved Document P, so the work is notifiable in England. That visit is a separate cost. We would rather tell you here than after you have ordered.

Harvia Cilindro PC90XW, 9kW, with Wi-Fi. The same column with 90kg of stones and a Xenio control panel that runs it from the MyHarvia app, so the cabin is hot when you walk out to it rather than when you remember to go and switch it on. The same dedicated circuit applies.

Harvia M3, wood burning. 16.5kW, rated for 6 to 13 cubic metres, 30kg of stones, with the chimney kit in the price. No supply, no electrician, no circuit, and no running cost tied to a unit rate. What it asks for instead is a flue through the roof, a basket of logs a session and a sweep twice a year.

Is this the right one for you

Who this is actually for.

Every product here is described with the honest opposite beside it: who it suits, and who should be looking at something else. If none of the descriptions below fits you, the right answer is elsewhere in the range, or elsewhere entirely, and we would rather say so.

You want four people in a glass fronted cabin, on a footprint a little over two metres square

The whole front is glass, floor to roof, with the door set into it, and the cabin is 2.26 metres across by 2.31 metres long. Four adults sit on two levels of bench that run 1.8 metres down both sides, with the heater in its bay by the door. The 9kW Harvia column heater, its 80kg of stones, the factory paint, the shingle roof in the colour you pick and the bucket, ladle and thermometer are all in the £7,620.

Worth confirmingyou want to lie down full length, or six in at once. The bench run is 1.8 metres and the room is a little over two metres each way. Four sit; nobody stretches out. The ICON 250 S is the next size up in the same shape.

You are happy to build it from a kit, and to have an electrician run one circuit, or a fitter flue it

It arrives flat packed on one pallet and goes together with two people, a drill and the maker's instructions. The electric heaters need a dedicated circuit: 40 amps single phase in 10mm² cable for the 9kW Cilindro, which is an electrician's job and not a plug. The wood burner needs no supply at all, and its chimney kit is in the price.

Worth confirmingyou want it delivered built, or holding its heat like an insulated cabin. The wall is a single 42mm stave with air on both sides, so it warms fast and cools fast, and on a January night the heater is working harder than it would in a cabin with insulated walls.

The product that gets used is the one worth recommending, and it is not always the largest one.

Will it work where you are

The measurements that decide it.

Read this before anything else. Things this size are almost never sent back because they were the wrong product. They are sent back because the pallet could not be set down, the parts would not reach the spot, or the ground under them was never going to hold them.

Footprint2.26m across, 2.31m long including the front overhang
HeightAbout 2,360mm to the top of the roof
Base requiredFlat, load bearing hard standing at least 2.2 × 1.5m; the maker's base frame is 2,100 × 1,394mm with the support positions drawn
Weight as a kitAbout 900kg on the pallet, before the heater and stones
Electrical supply40A single phase circuit in 10mm² cable, or 3 × 16A three phase, for the 9kW heater. None for the wood burner
Delivery pallet2.3 × 1.2 × 1.2m, about 900kg, tail lift to hard standing
Door opening690mm wide, about 1,900mm high, in the glass front
Planning positionUnder 2.5m, so permitted development usually applies even within 2m of a boundary, base permitting

The pallet is the one to respect. It weighs about 900kg and it moves on a pallet truck, which needs a hard, level surface from the lorry to wherever it stops. Gravel, grass, a kerb without a dropped edge or a single step all stop it, and at this weight a soft surface stops it too. If the pallet has to stop at the road, the parts are carried from there by hand, and the glass front wall is the one to plan the route for.

Check your garden in seven questions Free, instant, and it will tell you plainly when this is the wrong answer for your space.
What actually happens

From order to first use.

Here is each stage, and who does what. Before you order, email hello@tarnfell.com and we will confirm the current lead time for this cabin, delivery to your postcode, installation options, base requirements or anything else you would rather have settled first.

  1. Week 0

    Order and site check

    Base, access and your electrical supply are agreed before the order is placed with the factory. You arrange the base and the circuit, or the flue. Nothing goes into production until the total for your postcode is confirmed in writing.

  2. Weeks 1 to 14

    Built to order in Estonia

    The cabin is made to order, painted on the outside at the factory, and packed on one pallet with the heater, the stones and the accessory set. About 14 weeks at the moment; we confirm the current figure in writing when you order and tell you where it is in the process rather than leave you to wonder.

  3. Delivery day

    One pallet, set down at the kerb

    A lorry with a tail lift sets the pallet, 2.3 × 1.2 × 1.2m and about 900kg, down at the kerb or the nearest firm, level spot the pallet truck can reach. Count the parts against the list that day and photograph anything damaged. You will want two people to carry them through to the base.

  4. Build

    Frame, walls, staves, roof

    The base frame goes down first, then the back wall and the glass front, the staves between them, the benches and the shingles on the roof. Two people, a drill and the maker's instructions. If you would rather hand it over, installation is optional from £650, quoted for your site and confirmed before delivery.

  5. After

    Your electrician connects it, or your fitter flues it

    The Harvia Cilindro PC90 needs a dedicated 40 amp single phase circuit in 10mm² cable, or 3 × 16A on three phase, installed and certified by a qualified electrician. The M3 wood burner needs its chimney kit fitted through the roof and the flashing made good. Neither is included, and the cabin should not be used until it is done.

Living with it

What owning one actually involves.

The handful of things that decide whether this is still in use in year three.

The baseYours to provide, hard and level

A flat, load bearing slab or paved base at least 2.2 by 1.5 metres, laid before the pallet arrives. The maker's drawing gives a base frame of 2,100 by 1,394mm with the support positions marked, and it is the frame that carries the cabin, so those are the points to bear on. The base is not included.

PowerA dedicated circuit, or a flue

9kW at 230V is 40 amps on a circuit of its own, in 10mm² cable, installed and certified by an electrician before first use. On a three phase supply it is 3 × 16A. The Cilindro's timer and thermostat are on the heater; the Wi-Fi version adds a Xenio panel and the MyHarvia app. The M3 wood burner needs no supply at all, and its chimney kit is in the price.

AssemblyA flat pack, built by two people

A base frame, a back wall, a glass front with the door in it, the staves that make the sides and roof, the benches and the shingles, with the maker's instructions. Two people and a drill over a weekend. If you would rather hand it over, installation is optional from £650, quoted for your site and confirmed before delivery.

WeatherDry it, and let the timber be timber

The outside is painted at the factory. A single skin cabin is not heated continuously, so the timber can pick up damp marks or surface discolouring over a wet winter, and solid staves move slightly with the seasons. Heating the cabin after wet weather and airing it after every session is most of the answer, and none of it affects the structure.

ICON 220 XL from the front corner, showing the full height glass front wall, the door set into it and the shingle roof wrapping over the curved staves
ICON 220 XL straight on, the two level benches and the heater visible through the glass front
ICON 220 XL from the side, 2,310mm long, with the shingle roof over 42mm thermo treated staves
ICON 220 XL rear wall in 28mm tongue and groove thermo treated timber
Inside the ICON 220 XL, the two level benches along the side and the heater bay beside the glass door
Cutaway of the ICON 220 XL from above showing the two level benches on both sides and the heater by the door
What it costs to live with

The running costs, with the working shown.

The purchase price is public; the running cost rarely is. Ours are published with the assumptions stated, so you can check the sums rather than take our word for them.

An evening session, 9kW electric

about £3.50

Heat up: 9kW × 0.75 h is 6.75 kWh, because a room this size behind a glass wall takes about three quarters of an hour to bring up. Holding: 1.5 h at roughly half duty is another 6.75 kWh. That is 13.5 kWh at 26.11p, working shown in full so you can check it.

Twice a week, for a year

about £365

13.5 kWh × 2 × 52 is 1,404 kWh. Three evenings a week is nearer £550. Both figures move with your tariff and with the weather, which is why the unit rate and the assumptions are stated rather than buried. On the wood burner the figure is a basket of logs a session and no unit rate at all.

Setting it to start before you get home

no cost, one dial or one app

The Cilindro's timer runs it for up to four hours, or starts it by itself up to eight hours ahead. The Wi-Fi version does the same from the MyHarvia app, from wherever you are. The heater only draws full power while it climbs; once hot, the thermostat cycles.

Assumptions: electricity at the Ofgem price cap unit rate of 26.11p per kWh, 1 July to 30 September 2026, including VAT; three quarters of an hour to temperature at full draw on the 9kW heater; thermostat cycling near half power once hot. The wall is a single 42mm stave with no insulation behind it and the front is glass, so heat up is slower and heat loss faster than in an insulated cabin, and on a cold, windy night the real figure sits above these numbers rather than below them. These are calculated from the heater rating, not measured in use. Rerun the sums at your own tariff.

Owning it properly

What you have to do, and what the rules require.

Everything you have to do, and how often.

Job How often Who
Install and certify the heater circuit, or fit the flue 230V single phase, 40A, 3 × 10mm² cable, or 400V three phase, 3 × 16A, 5 × 2.5mm² cable for the Cilindro PC90. Outdoor circuits and rooms containing a sauna heater are notifiable work in England. The M3 wood burner needs its chimney kit fitted through the roof instead. Once, before first use A qualified electrician, or a competent fitter for the flue
Lay the base A flat, load bearing slab or paved base at least 2.2 × 1.5m, bearing on the support positions in the maker's base frame drawing. Once, before delivery You, or a groundworker
Build the cabin and fit the shingles Base frame, back wall, glass front, staves, benches, then the bitumen shingles on the roof, following the maker's instructions. Fit the shingles the same day the roof goes on. Once, over a weekend You and one other, or an installer
Dry it out after wet weather Heat the cabin after rain and once a month if it is standing unused, to keep surface mould off the timber. Air it after every session. After rain; monthly when idle You
Look after the paint The outside is painted at the factory. Recoat as the finish needs it, every few years in an exposed spot. The inside is left bare. Every few years You, an afternoon
Check the stones, or sweep the flue Restack the stones once a year and replace any that have crumbled; both electric heaters are supplied with them. On the wood burner, sweep the flue twice a year. Once a year, or twice for the flue You

Where this comes from.

Regulation and guidance, linked so you can read it yourself. None of it is our opinion.

Specification

Every figure the makers publish.

Lead time
About 14 weeks from order. We confirm the current figure in writing when you order.

Cabin figures from the maker's dimension drawing for this cabin and the maker's product sheet, heater figures from Harvia's published data. Where a figure is our own arithmetic it says so on the row.

In the price

What arrives, and what does not.

  • The cabin as a flat pack kit: 42mm thermo treated timber staves, the 28mm back wall, the full height glass front with the glass door in it, the two level benches on both sides, the floor and the base frame
  • The Harvia Cilindro PC90 9kW heater with its timer and thermostat, and its 80kg of stones. Or the Wi-Fi Cilindro, or the Harvia M3 wood burner with its chimney kit, if you choose one of those
  • Exterior paint, applied at the factory before it ships
  • Bitumen roof shingles in the colour you choose, every screw and fixing, and the maker's assembly instructions
  • The accessory set: bucket, ladle, thermometer and hourglass
  • Delivery on one pallet to the kerb at a mainland UK address
  • One point of contact for the order, the delivery and anything that goes wrong: us
  • The base. A flat, load bearing slab or paved area at least 2.2 × 1.5m
  • The electrical work. The 40 amp circuit is a qualified electrician's job and a separate cost. On the wood burner, fitting the flue through the roof
  • Assembly, unless you take the optional installation, from £650, quoted for your site
  • Moving the pallet beyond where the pallet truck stops. From there the parts are carried by hand
  • Anything not on this page. What you see here is what arrives
Before you commit

Reasons to buy something else.

Nothing can set a 900kg pallet down outside your property

Delivery is by tail lift lorry to the kerb, and the pallet is 2.3 metres long and about 900kg. A shared private road, steps to the kerb, a gravel drive or a double parked frontage all need solving before you order, not on the day. From wherever the pallet stops, every part moves by hand, and the route needs to take the glass front.

You want to lie down full length, or six in at once

The bench run is 1.8 metres and the room is a little over two metres each way. Four sit comfortably; nobody stretches out. If lying down or six seats is the point, the ICON 250 S is the next size up in the same shape and we will point you at it rather than sell you this.

You want a cabin that holds its heat through a British winter

A single 42mm stave with air on both sides, and a glass wall at the front, lose heat far faster than an insulated wall. This cabin heats quickly and cools quickly, and in January the heater is working hard to hold 80 degrees. If year round evening use at the lowest running cost is the aim, the cross laminated timber cabins in this range cost more for exactly that reason.

You are not going to build it, and do not want to arrange someone who will

It is a kit, and it needs two people, a drill and a weekend. Installation is optional from £650, quoted for your site and confirmed before delivery. If neither appeals, a cabin delivered built is the honest answer.

If any of these apply, say so and we will point you at what does suit you, including when that is a cheaper product or a different retailer.

The Tarnfell Standard

What we know, and how we know it.

Not a rating. A record of where every figure on this page comes from: what we have checked against a published source, what the maker has confirmed in writing, and what nobody has measured yet. The states describe our evidence, not the product.

Verified by Tarnfell against a published source Confirmed by the manufacturer in writing Not independently measured Information not yet published
Dimensions, door and base frame
Verified

Overall width, length and height, door opening, bench layout and the base frame with its support positions, checked against the maker's dimension drawing for this cabin with the glass front, sheet TIC26/220KE-PT11, and the maker's product sheet. Room volume is the maker's published figure, not yet checked against an assembled cabin.

Heaters and electrical supply
Verified

Output, room rating, stone quantity, fuse and cable ratings and control type for the Harvia Cilindro PC90 and PC90XW, and output, room rating and stone quantity for the M3, checked against Harvia's published product data. The maker's figure of about 11 cubic metres sits inside the Cilindro's 8 to 14 range and toward the top of the M3's 6 to 13, and the page says so. The documents are linked in the sources list further up this page.

Construction, timber and what is in the kit
Confirmed by manufacturer

Thermo treated timber, the benches, the roof covering, the factory paint, the accessory set and the pallet size and weight: from the maker's own price list, product sheet and its written confirmation of 11 September 2026. Stave thickness and the 8mm bronze glass front: from the maker's product sheet. None of it yet checked against an assembled cabin.

Warranty terms
Information not yet published

The maker's warranty terms for this cabin have not yet been received in writing, so no warranty period is stated on this page. It will be added the day it is confirmed, and if it is shorter than you would expect we will say so.

Lead time, assembly time and running cost
Not independently measured

About 14 weeks is the maker's current production figure and is confirmed per order rather than promised here. No independent measurement of assembly time, heat up time or heat loss exists for this cabin; the running cost figures are calculated from the heater rating and say so where they appear.

These states move as the evidence does. When a figure is measured on an installed cabin, by us or by an owner who shares the numbers, its state on this page changes to match, and the figure is corrected if it needs to be.

Before you decide

Weighing this against another sauna? Let us do the homework.

Choosing between two saunas takes evenings of research, so let us carry it. Name the other one you are considering and we will put the two side by side properly: sizes, heat, running costs, and what each asks of your garden and your fusebox. A written comparison or a call, whichever suits you, within 24 hours. And if the other one genuinely fits your space better, we will say so.

Free, no obligation, and your details go nowhere else.