Holl's Onyxia Barrel: 6 Person Outdoor Sauna
One configuration. The 8kW stove and its stones are in the price; the base and the circuit are yours to arrange.
£10,995.00
Harvia heater inside
- Covered outdoor terrace
- 40mm Finnish pine, thermally treated
- Harvia Vega 8kW stove and stones included
- Cabin
- 40mm Finnish pine, thermally treated, 2,250mm wide, 2,400mm deep and 2,260mm tall
- Inside
- Raw pine benches for six, with integrated LED backlighting
- Outside
- A covered terrace at the front, under the same roof
- Heater
- A Harvia Vega 8kW stove with its stones
- Glazing
- An 8mm tempered safety glass door and a panoramic half moon window across the rear
- Electrics
- A dedicated 35A circuit in armoured cable, wired and certified by an electrician
- Delivery
- One pallet, to the kerb
The largest cabin in the Holl's outdoor range: 2.25 by 2.4 metres and 2.26 tall, seating six, with a covered terrace at the front and a panoramic half moon window across the back. The 8kW stove and its stones are in the price.
Delivery & installation
Delivery is included in the price, kerbside to mainland Britain. Offshore, island and remote postcodes are quoted before you order. Nothing is added at the checkout and nothing is invoiced afterwards that you were not shown first.
Delivery to a mainland UK address is in the price. The cabin arrives on a pallet, set down at the kerb or the nearest firm, level spot the driver's pallet truck can reach; a pallet truck does not cross gravel, grass or a step. From there the parts move by hand, and this is a three to four person job rather than a two person one. We confirm the delivery arrangement for your address in writing when we process your order.
Offshore addresses, the Scottish Highlands and islands, and any address a lorry cannot reach are quoted separately before you order.
Installation is not in the price. It can be arranged for your site where you would rather not build it yourself, and the cost is confirmed before anything is delivered.
Warranty
Four years on the timber and two years on the electronics, the terms Holl's publish for this range.
The UK distributor administers the warranty and raises claims with the maker where needed. The cabin is sold for home use: commercial or very frequent use can affect cover.
Claims come to us. One email, and we deal with the distributor and the maker on your behalf rather than handing you a phone number.
Returns
Until the order is placed with the supplier 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. Do not book an electrician or an installer for a fixed date until the delivery has arrived and been checked.
Downloads
About this product
The largest cabin in the Holl's outdoor range: 225 by 240cm and 226cm tall, seating six, with a covered outdoor terrace at the front and a panoramic half moon window across the back.
The price includes the heater. A Harvia Vega 8kW stove and its stones ship with the cabin.
Built from 40mm Finnish pine treated by an eco friendly thermal process, with raw pine benches, an 8mm tempered safety glass door and integrated LED backlighting. The terrace is the part that changes how it gets used: somewhere to sit between rounds without going back indoors.
At 230V an 8kW element draws 34.8A, which is our arithmetic, and Harvia publish a 35A fuse for this heater. It runs on a dedicated circuit in steel wire armoured cable on a 30mA RCD, with the protective device sized and certified by a qualified electrician. Worth settling before you order rather than after.
Four year warranty on the timber, two years on the electrics, administered through the UK distributor.
- Secure paymentProcessed by Shopify Payments over an encrypted connection.
- Your details stay privateCard details are never stored on a Tarnfell system.
- Payment on confirmationWe take payment only once your order is confirmed.
- 14 day cancellation rightsCancel within 14 days of delivery, under the Consumer Contracts Regulations 2013.
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.
The terrace is what separates this from every other cabin in the range. Six people sit inside, and the covered deck at the front under the same roof is where they sit between rounds, in the rain, without going back indoors. That changes a sauna from a fifteen minute errand into an evening.
Worth confirmingyour garden is tight. This is 2.25 by 2.4 metres before you allow for the door swing and standing room at the terrace, and a cabin that fills a small garden stops being a pleasure to walk up to.
8kW at 230V is 34.8 amps on a dedicated 35 amp circuit in armoured cable. That is the same class of load as an electric vehicle charger, and whether your supply has the headroom is a calculation an electrician does on site.
Worth confirmingnobody has looked at your consumer unit yet. Find out first. At this price it is the one question worth answering before anything else.
The product that gets used is the one worth recommending, and it is not always the largest one.
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.
The 2.4 metre depth includes the covered terrace, so the sauna room itself is shorter than the footprint suggests. Measure the whole 2.25 by 2.4 metres for the base, then allow standing room in front of the terrace as well, because a deck you cannot step back from is a deck nobody uses.
From order to first use.
Here is each stage, and who does what. Delivery is estimated at 10 to 14 working days from order. If you would rather have stock, the date or anything else settled first, email hello@tarnfell.com before you order and we will confirm it in writing.
- Week 0
Order and site check
Base, access and your electrical supply are agreed before the order is placed with the distributor. You arrange the base and the circuit. There is nothing to configure on the cabin itself.
- Before it arrives
The base and the circuit
A flat, hard, level base at least 2.25 by 2.4 metres, and an electrician runs a dedicated 35A circuit to it in armoured cable and leaves it ready to terminate. Outdoor circuits and rooms containing a sauna heater are notifiable work in England, so this is not a job for a competent friend.
- Delivery day
One pallet, set down at the kerb
The cabin arrives on a pallet 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. Moving the parts to the base is a three to four person job.
- Build
Base frame, walls, glazing, benches
The base frame goes down, then the staves and the shell, the roof over both the room and the terrace, the glazed door and the rear window, then the benches, working from the maker's instructions. Three to four people. If you would rather hand it over, installation can be arranged for your address once you have ordered.
- Before first use
The electrician returns
The stove is fitted, connected and the circuit tested and certified. You should be handed a certificate. Then the stones go in, loosely, and the first heat cycle burns off the factory smell with the door open.
What owning one actually involves.
The handful of things that decide whether this is still in use in year three.
A flat, load bearing slab or paved base at least 2.25 by 2.4 metres, laid before the pallet arrives. The terrace stands on the same base as the room, so the whole footprint needs to be level rather than just the part with the stove in it.
8kW at 230V is 34.8 amps on a dedicated 35 amp circuit in armoured cable, protected by a 30mA RCD and certified by an electrician before first use. Worth knowing before you order: that is the same class of addition as an electric vehicle charger, and not every house supply has the headroom.
40mm Finnish pine, treated by heat rather than chemicals, with raw pine benches. Left alone the outside silvers over a few seasons. The terrace is the part that weathers hardest, because it is the only timber that is rained on and walked on, so it is the first place to look each spring.
A covered deck under the same roof is what makes this cabin get used in February rather than only in summer. It is also outdoor decking: it collects leaves, it goes slippery with algae in a shaded garden, and it wants a brush and an occasional wash rather than being left. Ten minutes a season, and it is the best ten minutes you will spend on the cabin.
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 arithmetic and change it for your own tariff.
about £3.13
Heat up: 8kW for an hour is 8 kWh. Holding: 1 hour at roughly 50% duty is 4 kWh. Total 12 kWh at 26.11p is about £3.13.
about £326
104 sessions at £3.13. A two seat outdoor cabin on a 4.5kW stove comes to about £152 on the same sums, which is what six seats and a terrace cost to heat.
a few pounds, every few years
Sauna stones crack and crumble with use, are restacked yearly and replaced when they do. They ship with the stove and they are the only consumable part.
Assumptions: electricity at the Ofgem price cap unit rate of 26.11p per kWh, 1 July to 30 September 2026, including VAT. Figures are calculated from the stove's rated output of 8kW, not measured on an installed cabin. Heat up is taken as one hour, our working figure for a cabin of this size with a covered terrace, and it says so here rather than being presented as the maker's.
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 stove circuit 8kW draws 34.8A at 230V, so a dedicated 35A circuit in steel wire armoured cable on a 30mA RCD. Outdoor circuits and rooms containing a sauna heater are notifiable work in England. | Once, before first use | A qualified electrician |
| Lay the base A flat, load bearing slab or paved base at least 2.25 by 2.4 metres, able to carry the cabin plus the people in it. | Once, before delivery | You, or a groundworker |
| Build the cabin Base frame, staves and shell, the roof over the room and the terrace, glazed door, rear window and the benches, following the maker's instructions. Three to four people. | Once, over a weekend | You and two or three others, or an installer |
| Restack and inspect the stones Lift them out, discard any that are cracked or crumbling, and restack loosely so air moves between them. Tightly packed or broken stones make the elements work harder. | Yearly | You |
| 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 |
| Oil or stain the outside, if you want the colour kept Heat treated pine silvers if left alone, which harms nothing. The terrace decking is the part that weathers hardest and benefits most from an oil. Brush it clear of leaves through autumn. | Every year or two, if you want the colour kept | You, an afternoon |
| Check the door and glass seals A cabin that heats and cools moves, and a base that settles takes the door out of square. Check the door closes cleanly and the glazing beads are sound at the start of each season. | Yearly | You |
Where this comes from.
Regulation and guidance, linked so you can read it yourself. None of it is our opinion.
- Outdoor circuits and rooms containing a sauna heater are notifiable electrical workApproved Document P, 2013 edition
- Outbuildings within 2 metres of a boundary are limited to 2.5 metres in height under permitted developmentPlanning Portal, outbuildings
- A heater needs about 1 kW for each cubic metre of sauna volume, and a square metre of glass or stone adds about 1.2 cubic metres to that requirementHarvia, how to select the correct heater power
- A 35 amp addition sits in the same load class as an electric vehicle charger or a hot tub, which the distribution network operator names as reasons a house may need a larger main fuseUK Power Networks, what do you need to upgrade
- Electricity unit rate of 26.11p per kWh, 1 July to 30 September 2026Ofgem energy price cap
Every figure the makers publish.
- Warranty
- 4 year wood, 2 year electrical warranty
- Lead time
- Estimated 10 to 14 working days from order. We confirm stock and your delivery date in writing when we process your order.
Cabin figures are from Holl's listing for the Onyxia Barrel and the UK distributor's product page. Where a figure is ours rather than the maker's, it says so.
What arrives, and what does not.
- The cabin: the 40mm thermally treated pine structure, the covered terrace, the roof, the glazed door, the panoramic rear window, the raw pine benches and every fixing
- The Harvia Vega 8kW stove and its stones
- Integrated LED backlighting, and the maker's assembly instructions
- Delivery on one pallet to the kerb at a mainland UK address
- Four years of the maker's warranty on the timber and two on the electronics
- 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 2.25 by 2.4 metres
- The electrical work. A dedicated 35A circuit, run, terminated and certified by an electrician
- Assembly, unless you ask us to arrange it
- Moving the pallet beyond where the pallet truck stops. From there the parts are carried by hand
- Stain or oil for the outside and the terrace decking. Left alone the pine silvers, which harms nothing
- Delivery to offshore and remote postcodes, which is quoted before you order
Reasons to buy something else.
Delivery is by lorry to the kerb. 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. This is the largest cabin in the range and from wherever the pallet stops, every part moves by hand.
The stove will not run from a socket. 34.8 amps on its own circuit is the same class of addition as an electric vehicle charger, and whether your house can take it is a calculation an electrician does on site rather than something anyone can promise from a web page.
The footprint is 2.25 by 2.4 metres and the terrace only works if you can step back from it. In a small garden this becomes the garden rather than something in it. If space is tight, the Cocoon or a cube cabin sits better and we would rather point you there.
A single skin timber cabin loses heat far faster than an insulated building. It heats and cools quickly, and in January the 8kW stove is working hard to hold 80 degrees. If year round evening use at the lowest running cost is the aim, a fully insulated cabin costs more for exactly that reason.
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 one we do not sell.
What we know, and how we know it.
Where every figure on this page comes from, with the source beside it.
- Dimensions, timber, glazing and what is supplied
-
Verified
Taken from Holl's listing for the Onyxia Barrel and the UK distributor's product page, which agree on 225 x 240 x 226cm, six seated, 40mm Finnish pine treated by a thermal process, raw pine benches, the 8mm tempered safety glass door, the panoramic half moon rear window, the integrated LED backlighting and the covered outdoor terrace.
- Electrical supply
-
Verified
8,000 watts at 230 volts is 34.8 amps, which is our arithmetic rather than a claim. Harvia publish a 35 amp fuse for this heater, and the final protective device is the installing electrician's calculation on site. Armoured cable and a 30mA RCD are what an outdoor circuit requires under BS 7671. The cable size is the installer's calculation on site and this page does not state one.
- Weight, pallet and assembly
Three to four people is the handling figure the distributor gives. The distributor's guidance for this range is 10 to 14 working days, which is the estimate on this page, and we confirm your date in writing when we process your order.
- Warranty administration
Four years on the timber and two on the electronics are the maker's published terms. Claims run through the UK distributor, which raises them with the maker where needed, and you deal only with us. The cabin is sold for home use: commercial or very frequent use can affect cover.
The three closest to it.
Holl's Onyxia Cube: 4 Person Outdoor Sauna, Glazed Front
£10,995.00- 4 people, 210 × 160 × 220cm
- 40mm ThermoWood
- 8kW Harvia Vega stove included
Holl's Hestia Lounge 210: 4 to 6 Person Outdoor Sauna
£8,990.00- 4 to 6 people, 205 × 210 × 220cm
- Covered terrace
- 6kW stove included
Holl's Orphée Lounge 240: 5 to 6 Person Outdoor Sauna
£8,990.00- 5 to 6 people, 205 × 240 × 215cm
- Barrel with covered terrace
- 9kW Holl's Vulkano stove included
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 send a straight comparison, including where the other one wins.