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You've been dreaming about it - stepping into your own sauna after a long day, heat wrapping around you, stress melting away right there in your garden or home. But before that dream becomes reality, there's a practical question that needs answering: how much does a sauna cost to build?
Let's walk through this together. No hidden surprises, no vague estimates—just honest, detailed information about what building a sauna in the UK actually costs in 2025. Whether you're considering a simple outdoor barrel or a custom indoor sanctuary, we'll break down every expense so you can plan with confidence.
Let's get straight to it: building a sauna in the UK costs anywhere from £900 for a basic DIY kit to £17,000+ for a high-end custom build. Most people find themselves in the £3,000 to £8,000 range for a quality outdoor sauna, or £3,600 to £12,000 for an indoor installation.
Here's what we're going to do: walk you through every single cost you need to consider—materials, labour, heating systems, electrical work, foundation, and all those extras that add up. By the end, you'll know exactly where your money goes and, more importantly, where to invest for the best experience and where you can save without compromising quality. No surprises, just honest breakdowns.
Your first major decision significantly impacts how much does it cost to build a sauna, and it comes down to this: prefabricated kit or custom build?
These are the accessible entry point for most people. A sauna kit arrives with pre-cut pieces, clear instructions, and everything you need except the electrical work and foundation. We've helped countless people through this exact choice, so let's break down what each option actually costs based on real projects and years of experience:
Budget kits (2-person): £900 - £2,500
Mid-range kits (2-4 person): £2,500 - £6,000
Premium kits (4-6 person): £6,000 - £17,000
Installation costs for kits: £300 - £2,160
Most kits can be assembled by 2-4 people over a weekend, but you'll still need a qualified electrician for the wiring (see electrical costs below).
If you're building from scratch or converting an existing space, you're looking at custom construction where every choice is yours. This gives you complete creative freedom to adjust every detail to your exact needs—but it comes with its own set of challenges, including higher costs and the need for professional help throughout the process.
Basic custom builds: £4,000 - £7,000
Mid-range custom builds: £7,000 - £12,000
Luxury custom builds: £12,000 - £30,000+
Professional installation: £1,500 - £10,000+ Custom builds require more labour—carpentry, electrical, potentially plumbing. Expect installation to represent 40-50% of your total project cost.
Understanding material costs helps you make informed choices about where to invest and where to save. Lucky for you, we've been working with these materials for years, so we know exactly what's worth the investment and what isn't.
The type of wood you choose dramatically affects both the initial cost and long-term performance.
Pine: £40 - £55 per m²
Hemlock: £50 - £70 per m²
Cedar (Standard grade): £55 - £90 per m²
Western Red Cedar (Premium): £90 - £150 per m²
Nordic Spruce: £45 - £75 per m²
For a typical 2-person outdoor barrel sauna (approximately 8-10 m² of wood needed), you're looking at:
Here's where we strongly recommend paying close attention: proper insulation isn't optional - it's essential for efficiency and preventing moisture damage. Skimp here, and you'll pay for it in higher energy bills and potential structural problems for years to come.
Waterproofing membrane: £40 - £60 per m²
Mineral wool insulation: £50 - £85 per m²
Foil-backed insulation boards: £30 - £50 per m²
For a 6x6 foot (roughly 3.3 m²) indoor sauna with walls and ceiling: Total insulation costs: £500 - £900
Now here's a place where you can save a penny or two without compromising your sauna experience. Our recommendation? Choose the basics that serve their purpose well. A solid wood door with proper seals does the job perfectly - you don't need to splash out on premium glass unless the aesthetic really matters to you.
Standard sauna door (wood): £300 - £600
Glass door (tempered safety glass): £500 - £1,200
Additional windows: £150 - £400 each
Here's what people don't always realize: your heating choice isn't a one-and-done cost. Yes, you'll pay upfront for the heater itself, but you'll also have ongoing running expenses every time you fire it up. The heating system you choose now will impact your wallet for years to come, so it's worth dedicating time to make the best decision for your budget—both now and long-term.
Basic electric heaters (4.5-6 kW): £300 - £600
Mid-range electric heaters (6-8 kW): £600 - £900
Premium electric heaters (8-10 kW): £900 - £1,500
Professional-grade electric heaters: £1,500 - £2,500
Basic wood-burning stoves: £800 - £1,500
Premium wood-burning stoves: £1,500 - £3,500
Additional costs for wood-burning:
Basic infrared panels (1.5-2 kW): £400 - £800
Premium infrared systems (full spectrum): £800 - £2,000
Read also: Infrared vs. Traditional Sauna: A Comprehensive Comparison
Here's something people often overlook when budgeting: your sauna needs somewhere solid to sit. These foundation costs might not be as exciting as choosing your cedar or picking out lighting, but skip them and you'll have problems from day one, we can guarantee you that.
Gravel base: £200 - £400
Paving slabs: £300 - £600
Concrete pad: £500 - £1,500
Decking platform: £800 - £2,000
Floor reinforcement: £300 - £800
Floor protection: £200 - £500
Never skip professional electrical work. This is where proper certification and safety compliance matter most.
Basic wiring for electric heater: £300 - £600
Mid-range electrical work: £600 - £1,000
Comprehensive electrical package: £1,000 - £1,800
Electrician hourly rate: £40 - £80 per hour Rates vary by region, with London and South East typically higher.
Important: Your electrician must be Part P certified. They'll handle building control notifications (typically £170, up to £690 in some areas of Wales and East England).
Most dry saunas don't need plumbing, but steam saunas or those with showers do.
Basic water connection: £200 - £400
Full plumbing for steam sauna: £500 - £1,500
Plumber daily rate: £300 - £400 Expect 1-2 days for steam sauna installations.
Proper ventilation prevents moisture damage and ensures safety.
Basic ventilation:
Active ventilation:
For indoor saunas, proper ventilation isn't optional—budget at least £250 for a decent system.
These elements complete your sauna experience.
Benches:
Lighting:
Sound system: £200 - £800
Accessories:
Exterior finishing (outdoor saunas):
Let's put this all together with realistic scenarios for the UK market.
Scenario: 2-person barrel sauna kit, outdoor placement, basic features
Total: £2,800
This is the most affordable path to sauna ownership while maintaining quality and safety. If you're looking for a compact solution in this price range, our Orson - Compact Small Garden Sauna offers excellent value with traditional design and straightforward installation.
Scenario: 4-person cedar barrel sauna, quality features, professional assembly
Total: £7,670
This represents excellent value - a proper, enjoyable sauna that will last for years. Our London - Small Outdoor Sauna fits perfectly into this category, offering premium construction and capacity for 4-6 people with professional-grade features at a competitive price point.
Scenario: 6-person custom cedar cabin sauna with changing room, outdoor
Total: £14,870
A truly luxurious outdoor retreat that adds significant value to your property. For those seeking a ready-made premium solution without the complexity of custom building, the Hazelwood - Frame Sauna With Closed Terrace delivers comparable luxury with spacious 6-person capacityand high-end finishes - often at better value than a full custom build.
Scenario: Converting a 6x8 ft spare room or large closet, 2-3 person capacity
Total: £6,970
Indoor installations cost more due to ventilation, waterproofing, and integration requirements. However, if you have the outdoor space, a pre-built option like our Sauna Ellis can deliver similar 2-3 person capacity at roughly half the cost, with easier installation and no complex indoor integration work.
Scenario: Custom-designed 8x10 ft indoor sauna in a dedicated space
Total: £18,850
This is the upper end - a spa-quality installation that becomes a genuine home sanctuary. Before committing to a full custom build, consider whether models like the Churchill or Wellington might meet your needs with their premium features, larger capacities, and professional-grade construction—potentially saving thousands while still delivering that luxury sauna experience.
How much to build a sauna is only part of the picture. Let's talk about ongoing costs.
Traditional electric sauna (6 kW heater):
Infrared sauna (1.5 kW):
The energy efficiency difference is substantial if running costs matter to your decision.
Annual maintenance budget: £200 - £500
This includes:
Heater replacement: £300 - £1,500 (typically after 8-15 years) Bench refurbishment: £200 - £600 (every 5-10 years if needed) Door seal replacement: £50 - £150 (every 3-5 years)
Most quality saunas require minimal maintenance if built correctly and cleaned regularly.
After helping countless people build their saunas, we've learned where you can economize and where you absolutely shouldn't.
1. Choosing a kit over custom building
Prefabricated kits can save you 30-40% compared to custom builds. Unless you have specific space constraints or design requirements, kits offer excellent value.
2. Mix wood grades strategically
Use premium cedar where it matters (benches, interior visible surfaces) and hemlock or treated pine for structural elements you won't see. This can save £500-1,000 on materials while maintaining quality where it counts.
3. DIY the assembly (but not the electrical)
If you're handy, assembling a kit yourself saves £800-2,000 in labour. Most sauna kits are designed for DIY assembly with clear instructions. Just remember—always hire a qualified electrician for all electrical work.
4. Start simple, upgrade later
Begin with basic lighting and add mood lighting later. Start with a simple sound system (even a Bluetooth speaker) before investing in built-in systems. You can always enhance your sauna as the budget allows.
5. Choose outdoor over indoor
Outdoor installations typically cost £1,000-3,000 less than indoor because you avoid extensive ventilation systems, waterproofing complications, and interior integration challenges.
6. Buy during off-season
Many sauna suppliers offer 10-25% discounts during autumn and winter months. Patient shopping can save hundreds of pounds.
7. Standard sizes are cheaper
Custom dimensions cost significantly more than standard sizes. If standard dimensions work for your space, stick with them.
8. Electric over wood-burning for initial cost
While wood-burning stoves offer authentic experience, they cost more upfront (£800-3,500 vs. £300-1,500) and require chimney installation. Electric heaters are simpler and cheaper initially.
1. Electrical work
Never compromise on electrical safety. Always hire a qualified, Part P-certified electrician. This isn't the place to save £100-200. Poor electrical work is dangerous and could void insurance.
2. Heater quality
Your heater is the heart of your sauna. A cheap heater that breaks down or provides inconsistent heat ruins the experience. Budget at least £600-900 for a reliable mid-range electric heater.
3. Proper insulation
Cutting insulation costs is false economy. Poor insulation means higher running costs forever, moisture problems, and inconsistent heat. Invest in proper mineral wool insulation—it pays for itself in energy savings.
4. Wood quality for benches
You'll sit or lie directly on these benches while hot and sweating. Cheap wood with knots creates uncomfortable hot spots. Splurge on quality cedar or hemlock for benches even if you economize elsewhere.
5. Foundation preparation
A level, stable foundation prevents structural problems, moisture issues, and premature wear. Whether it's £200 for gravel or £1,000 for concrete, do it properly.
6. Door seals and weatherproofing
Proper sealing maintains temperature efficiency and prevents moisture escape (for indoor saunas). Don't skip weatherproofing membranes or quality door seals.
7. Ventilation (especially for indoor saunas)
Adequate ventilation prevents dangerous CO₂ buildup, reduces moisture damage, and maintains air quality. Budget properly for this essential safety feature.
Planning permission: Usually not required for outdoor saunas under permitted development rules, but verify with your local council. If needed: £206 for householder planning application.
Building control notification: £170 (£690 in some areas) Required for electrical work, new heating installations, and structural changes.
Building regulations compliance: Most sauna installations require building regulations approval for:
Your qualified electrician can often handle notifications as part of their service if they're on the Competent Person's register.
Difficult access surcharge: £200 - £800 If delivery trucks can't reach your installation site easily, expect additional charges for crane hire or manual carrying.
Ground leveling: £300 - £1,000 Sloped sites need preparation before foundation installation.
Landscaping restoration: £200 - £1,000 Budget for repairing lawn, paths, or gardens affected during installation.
Contact your home insurance provider when installing a sauna. Most policies cover it as a fixed outbuilding or home improvement, but you should notify them. Expect potential premium increases of £20-80 annually.
Here are some realistic expectations you can actually lean on - we've seen these timelines play out on real projects, so we know they're accurate. Keep in mind that weather can slow outdoor builds, and sometimes electricians or builders get booked up for weeks, so add a bit of buffer time to whatever you're planning. But here's what you can genuinely expect:
Prefabricated kit (DIY):
Prefabricated kit (professional installation):
Custom outdoor build:
Custom indoor conversion:
Weather can affect outdoor projects, so add buffer time during wet seasons.
You've planned the build, chosen your materials, sorted the installation - now let's talk about the final step in your journey. Once all the work is done and your sauna is ready to enjoy, here's what you can expect for your monthly and yearly running costs. Think of this as your long-term budget snapshot.
Financial perspective:
Wellness perspective:
Practical perspective:
Most sauna owners tell us the same thing: they wish they'd built it sooner. The initial cost to build a sauna feels significant, but the daily value accumulates quickly.
Building a sauna in the UK is more accessible than many people think. Whether you're investing £2,800 for a simple outdoor kit or £18,000 for a luxury custom installation, you're creating something valuable - a dedicated space for health, relaxation, and returning to yourself.
The numbers we've shared represent real costs from real projects across the UK in 2025. Your actual costs may vary based on location (London and South East typically run 15-25% higher), specific choices, and site conditions. But now you understand where the money goes and can budget confidently.
Start by deciding what type of sauna calls to you. Visit showrooms if possible. Request quotes from at least three suppliers or builders. And if you haven't yet, read our building guide to understand the construction process.
Have questions about delivery, installation, or anything else related to our hot tubs and saunas? We're here to help! Fill out the form, and our dedicated team will assist you promptly. Your satisfaction is our priority. Get in touch today!
