Straight answers, including the unhelpful ones.
Everything people ask us before they spend real money. Where the honest answer is that it depends, we say what it depends on.
Before you buy.
Why is your range so small?
Because every product passes three gates before it is listed: we have to understand how it is built and what fails first, test the claims against British conditions rather than a Nordic summer, and agree proper warranty, parts and lead time terms with the maker in writing. Products fail those gates regularly.
The range grows as partnerships complete. It grows slowly on purpose.
Can I see one before I buy?
Where a manufacturer has a UK showroom we will tell you where it is, even when that means you buy nothing from us today. If there is no showroom for the model you are looking at, we will say so rather than imply otherwise.
Traditional, infrared or wood fired?
They are three different ways to take a sauna, not three versions of one. A traditional sauna heats the air: an electric heater warms a bed of stones, the room sits at around 70 to 90°C, and water on the stones gives you steam. An infrared cabin heats you rather than the air: emitters around the bench warm your skin directly, the makers rate the cabins at up to about 60°C, there are no stones and no steam, and the warm up is shorter. Wood fired is a traditional sauna with a stove in place of the electric heater.
Where it goes and what your electrics allow usually settle it. Every outdoor cabin on this site is traditional; every infrared cabin is built for indoors. Every traditional electric heater here needs its own circuit from an electrician, from 16A for a 3.5kW heater upwards. The smaller infrared cabins plug into an ordinary 13A socket and the larger ones need a circuit too. Each product page gives the exact figure.
Two cabins are hybrids, with a traditional heater and infrared panels in the same room. Wood fired is offered on the two Harvia barrels and needs no heater circuit at all. If you will use it two or three times a week on a whim, electric wins on sheer usage; if it is a deliberate weekly occasion, wood is very hard to beat. One thing catches people out: in a smoke control area a wood stove in a roofed garden structure is subject to the same rules as your house chimney. Check with your council before you buy.
How do you make money?
We buy from manufacturers and sell to you. There are no commissions, no referral fees and no payment from anyone for placement or for a favourable mention. If a product appears here it is because we think it is good.
Are your prices negotiable?
No, and we would rather say that than run a permanent discount that makes the listed price meaningless. What we will do is tell you honestly when a cheaper product in the range suits you better than the one you were looking at.
Do you offer finance?
No. Consumer credit is a regulated activity and we would rather stay out of it entirely than be in it badly. Prices are in sterling, payable at checkout.
Getting it into your garden.
What does delivery cost?
Nothing extra on mainland Britain. Delivery is included in the price of every sauna and cold plunge, kerbside to England, Wales and mainland Scotland, and nothing is added at checkout.
The Scottish Highlands, islands and any address a lorry cannot reach are quoted before dispatch. If the figure does not suit you, cancel at that point and we refund you in full. For Northern Ireland, the Isle of Man and the Channel Islands, write to us before ordering and we will quote. Accessories are posted anywhere in the United Kingdom at no charge.
Do you install?
No. Every sauna arrives as a kit you can build yourself. If you would rather not, tick the installation box when you order and we introduce you to an independent installer near you. Expect it to cost from about £650.
You agree the price and the date with the installer and pay them directly. Their contract is with you, not with Tarnfell. Electrical work is separate and needs a qualified electrician.
How do I know it will fit through my gate?
Measure the narrowest point along the whole route, not the gate. The gate is rarely the problem. The pinch point three metres past it usually is: a drainpipe, a meter box, a corner where a fence stops you swinging wide.
Send us photographs of the route and we will tell you before you order, not on the day.
What base do I need?
A sauna wants a level, free draining base with air able to move underneath. A plunge wants a base rated for the filled weight, which is much more than the empty weight: water is a kilogram a litre.
The base should be finished and cured before delivery. It is the least glamorous line in any specification and the one that decides whether you still own this in ten years.
Will I need an electrician?
For any traditional sauna, yes. Every heater on this site needs its own circuit, installed and certified by a qualified electrician, from 16A for a 3.5kW heater to 50A for the largest. The larger infrared cabins need one too. The smaller infrared cabins and all three cold plunges run from an ordinary socket with RCD protection, and each product page says which applies.
Where you need one, get a rough figure early. A long cable run through an established garden is a real cost and belongs in your budget rather than in a surprise, and the job has a lead time of its own.
Do I need planning permission?
Usually not, as most garden buildings of this size fall under permitted development, but there are real exceptions: listed buildings, conservation areas, land in front of the principal elevation, and height limits near a boundary. We are not planning consultants. Your local authority will answer definitively and it costs nothing to ask.
Living with it.
What will it cost to run?
For any electric sauna you can work it out: heater rating in kilowatts, times hours running, times your unit rate. At the Ofgem price cap unit rate of 26.32p per kWh (1 October to 31 December 2026), a 6kW traditional heater running flat out for an hour is about £1.58, and a 2kW infrared cabin for an hour is about 53p. Those are ceilings, because a heater cycles off once the room is at temperature, but a traditional room also takes time to warm before the session starts.
For a cold plunge, the Harvia Frosty and IceFall pages show the sums. Insulation and a closed cover decide the bill far more than chiller size does, and a well insulated plunge costs less to hold in January than in July, because the ambient air is helping rather than fighting.
How much upkeep is a plunge, really?
More than nothing and less than a hot tub. Expect a short weekly routine of checking and dosing, a filter change on the manufacturer's schedule, and a full drain and refill periodically. Ask any seller how many minutes a week it takes. If the answer is vague, assume more than you hope.
Can I leave it out all winter?
The outdoor saunas and all three cold plunges are built to live outdoors in Britain. The indoor cabins, including every infrared one, are not, and each product page says which it is. For a plunge, check the rated ambient range at both ends, because some chillers are specified down to five degrees and not below, and ask what the unit does on its own if pipework approaches freezing.
Who fixes it in year three?
We do. One email to us and we handle the manufacturer for the life of the warranty, and we will still source the part and make the call after it ends.
Does cold water actually do what people say?
Some of it, and less than the loudest claims suggest. There is a real and growing body of research worth taking seriously, and a great deal of confident marketing language running well ahead of it.
We will tell you what is well supported, what is promising and what is somebody's advertising, and we would rather lose a sale than overstate the third one. No product here will fix your sleep, your mood and your marriage.
Still not answered? Ask us and we will add it here