Buying an Outdoor Sauna: Key Things to Consider
Buying an Outdoor Sauna: Key Things to Consider
From kit inclusions to foundations, heater requirements, and the true total cost — everything you need to know before you buy.
Buying an outdoor sauna feels exciting — until the research phase begins and layers of complexity that most buyers never anticipated start to emerge. From understanding what's actually included in a kit to calculating heater requirements, preparing a suitable foundation, and budgeting for the true total cost, the decisions involved go far deeper than simply picking a style you like online.
This guide covers everything you need to know before buying an outdoor sauna: what's in a kit, how to choose the right size, what base you need, heater and electrical requirements, installation realities, and how to avoid the most common — and costly — mistakes.
1. Understand What Comes in the Kit (and What Doesn't)
Not all outdoor sauna kits include the same components — comparing kit inclusions is one of the most important steps before purchasing, and one of the most commonly overlooked.
When you see two outdoor saunas listed at very different price points, the gap often comes down to what each price actually includes. One kit might include the heater, LED lighting, and accessories. Another might include none of those things. Without checking, you can't compare prices meaningfully.
Flat-Packed vs. Fully Assembled Saunas
There are two primary delivery formats for outdoor saunas:
Flat-packed saunas are delivered in components and assembled on-site. These offer more flexibility for properties with restricted access, narrow gates, or awkward positioning requirements.
Fully assembled saunas arrive as a complete unit and are placed directly into position. These typically require crane delivery, which adds a logistical layer to your planning.
Kit Inclusions Checklist — Ask Before You Buy
Before committing to any outdoor sauna purchase, confirm the following with your supplier:
- Is the sauna fully assembled or a flat-packed/panel kit?
- Is the heater included, or is it sold separately?
- Are LED lights included? Are they dimmable?
- Are accessories included — bucket, ladle, thermo-hygrometer, sand timer?
- Is installation included, or is it quoted separately?
- Is freight included, or is it additional?
This checklist ensures you're comparing like-for-like when prices differ significantly between suppliers.
2. Choose the Right Sauna Size and Layout
Choosing the wrong sauna size is one of the most common buyer mistakes — always think about how you'll actually use it, not just how many people it's rated for.
A sauna rated for four people sounds generous, but if two of those people want to lie down comfortably, you may find yourself needing a larger model than you anticipated.
Sauna Capacity: 2-Person, 4-Person, and 6-Person
| Capacity | Best For | Notes |
|---|---|---|
| 2-person | Couples, small spaces | Good entry point; limited if you want to lie down |
| 4-person | Small families, regular entertaining | Most popular size for residential use |
| 6-person | Larger households, hosting groups | Requires larger outdoor footprint and higher kW heater |
Bench Layouts to Consider
The bench configuration shapes how your sauna feels in daily use:
- I-bench: A single bench along one wall — space-efficient and straightforward
- L-bench: Bench wraps around two walls, allowing more users and comfortable lying-down positions
- Facing benches: Two benches opposite each other — a traditional, social layout well suited to larger saunas
If lying flat is important to you, you'll need a minimum bench length of approximately 1.7–2 metres.
Internal vs. External Dimensions
This distinction catches many buyers off guard. While quality outdoor saunas commonly feature wall thicknesses of 40mm to 70mm, high-end, premium insulated sauna systems can go beyond 100mm. In a 2-person sauna, that wall thickness on each side meaningfully reduces the usable interior space compared to the external footprint. Always ask for internal dimensions and evaluate usable bench space before purchasing based on external measurements alone.
Outdoor Space and Clearance
Allow at least 0.5 metres of space around the sauna during installation so there is enough room to work around the unit. Once installation is complete, the sauna can be moved closer to a wall or corner if required.
3. Consider Where You Will Place Your Sauna
Where you place your outdoor sauna affects not just aesthetics — it determines delivery access, installation requirements, and the long-term performance and lifespan of your sauna.
Suitable Base and Foundation Options
A solid, level base is essential for any outdoor sauna. Acceptable foundation types include:
- Concrete slab
- Flagstone
- Timber or wooden deck
- Bricks or pavers
- Compacted gravel
Never place your outdoor sauna directly on bare earth. Direct ground contact causes structural instability, accelerates timber decay, increases moisture damage risk, and creates ongoing cleaning difficulties. A hard, level surface is non-negotiable for longevity and performance.
If a suitable foundation isn't already in place, factor the cost of installation into your budget before purchasing.
Delivery and Access Requirements
Most outdoor saunas are delivered to the kerbside or driveway. From there, the installation team or the buyer carries panels and components to the final location. For fully assembled saunas, a crane is typically required to lift and position the unit — confirm this with your supplier well in advance and ensure adequate vehicle and crane access exists before ordering.
Slopes, narrow side gates, overhead obstacles, and tight corners can all complicate delivery significantly. Walk your access route critically before placing an order.
4. Check the Construction Quality
Construction quality directly affects how well your sauna performs, how long it lasts, and how much you'll spend on heating — it deserves the same scrutiny as the price tag.
Timber Type
Interior and exterior timber selection matters both for durability and comfort. Common options include:
Exterior:
- Spruce: A popular and cost-effective timber used widely in sauna construction.
- Pine: Another common option, particularly for outdoor sauna cladding.
- Western Red Cedar: Naturally durable and moisture resistant, with a distinctive appearance and aroma.
For outdoor saunas, thermally modified timber (Thermowood) is a higher-quality option worth looking for. The thermal treatment process reduces moisture absorption and improves dimensional stability, helping the timber better withstand changing outdoor conditions and reducing moisture-related movement over time. Thermo-pine and thermo-spruce are commonly used for exterior sauna construction and can provide greater durability and stability than regular untreated timber.
Interior:
- Aspen: A popular sauna timber that has low thermal conductivity, making it comfortable against the skin and well suited to benches and backrests.
- Pine: Commonly used for sauna interiors and offers a more traditional, knotty appearance.
- Alder: A durable, low-resin timber with a warm appearance and relatively low thermal conductivity.
- Western Red Cedar: Naturally durable, aromatic and resistant to moisture.
For the best build quality, look for thermally modified timber for the benches and backrests. Compared with regular timber, thermal modification improves dimensional stability and resistance to moisture, helping these high-use surfaces better withstand repeated heating and cooling and last longer over time.
Wall Thickness
Thicker walls generally provide better heat retention, faster heat-up times, and improved thermal efficiency, which can help reduce running costs over time. Quality outdoor saunas typically feature wall thicknesses from 40mm up to 70mm or more, while high-end, heavily insulated sauna systems can exceed 100mm.
Thicker wall construction can also contribute to greater structural integrity, rigidity, and overall durability, helping the sauna withstand outdoor conditions and maintain its performance over many years. Thinner-walled saunas may be cheaper upfront, but they can offer less insulation and structural robustness compared with more substantial wall assemblies.
Insulation
Insulation is generally found in more premium, higher-cost outdoor saunas and improves heat retention and efficiency. Its benefits are more pronounced in colder climates, where greater insulation helps reduce heat loss. In milder climates, such as Australia, uninsulated saunas can perform just as well with an appropriately sized heater — you may simply need a slightly more powerful heater to reach and maintain temperature.
Weather Resistance
For a structure that lives outdoors year-round, weather resistance is critical:
- Roof construction: Confirm the material (shingles, metal, rubber membrane) and whether it's UV and rain resistant
- Door and window seals: Check for weatherproofing features that prevent heat loss and moisture ingress
- Exterior timber treatment: Lower-range saunas generally come with untreated exterior timber, while higher-range models may arrive pre-treated. If the timber is untreated, it will need to be protected with a suitable exterior oil or paint after installation and maintained over time.
Glass Quality
As a minimum, all glass in an outdoor sauna should be tempered safety glass. Beyond that, thickness matters — thicker glass retains heat better and is more durable under thermal cycling. Premium saunas feature double-glazed glass, which offers significantly better heat retention and is worth the investment if your budget allows.
5. Understand Heater Requirements
Your heater choice affects your sauna experience, running costs, and what infrastructure you need installed — it deserves careful consideration before you finalise your purchase.
Electric vs. Wood-Fired Sauna Heaters
| Factor | Electric Heater | Wood-Fired Heater |
|---|---|---|
| Convenience | High — push-button operation and remote control option | Lower — requires wood and fire management |
| Maintenance | Low | Higher — ash removal, chimney care |
| Best for | Residential suburban use | Rural/remote properties, traditional experience |
| Electrical requirement | Yes | No electrical supply needed |
| Heat-up time | 30–60+ minutes depending on the stone mass | 45–60+ minutes depending on the stone mass |
| Running cost | Electricity tariff dependent | Firewood cost |
| Installation complexity | Licensed electrician required | Simpler, no electrical work |
Electric heaters are the most common choice for prefabricated residential outdoor sauna kits because they are convenient, easy to operate, and require less ongoing maintenance. Browse our range of electric and wood-fired sauna heaters to compare options for your sauna.
Choosing the Correct Heater Size (kW)
Most sauna suppliers will recommend a heater size for each specific model. If selecting a heater separately, use this formula:
- Calculate sauna volume: Length (m) × Width (m) × Height (m) = Volume (m³)
- Account for glass areas: Add glass area (m²) × 1.2 to the sauna volume
- Match the adjusted volume to the heater manufacturer's kW recommendations
- Always confirm with the heater manufacturer directly — requirements vary between brands
Electrical Requirements
Before purchasing an electric sauna heater, speak with a qualified electrician to confirm:
- Available amperage at your property
- Whether your solar or battery system can support the additional load
- Distance from the switchboard to the sauna location (this affects cable sizing and cost)
Sauna heaters are high-load appliances. Electrical capacity must be verified before installation — not after.
Single-Phase vs. Three-Phase Power
Most residential sauna heaters operate on single-phase power. However, larger saunas, high-kW heaters, or saunas with substantial glass areas may require three-phase power. Confirm power supply requirements with both your sauna supplier and your electrician before placing your order — discovering a three-phase requirement after purchase creates significant additional cost and delay.
Heater Controls — Manual vs. Wi-Fi Enabled
| Feature | Manual Controls | Wi-Fi-Enabled Controls |
|---|---|---|
| Operation | Direct panel or dial adjustment | Smartphone app |
| Scheduling | Yes — using a mechanical timer or delay function | Yes — schedule heating times in advance, including daily or weekly schedules |
| Remote preheat | No | Yes |
| Reliability | Simple, with fewer electronic components and failure points | More dependent on connectivity and electronic components |
| Temperature Control | Adjusted using a mechanical thermostat or dial | Precise digital temperature settings via control panel or app. Generally allows a higher maximum temperature setting than manual |
| Installation | Simpler with less electronic components | More complex due to extra sensors and electronic components |
| Best for | Occasional users | Regular or daily sauna users |
6. Installation — DIY or Hire a Professional?
Whether you can install an outdoor sauna yourself depends heavily on the kit type and your construction experience.
Panel-style sauna kits are the most DIY-friendly format — they are designed for on-site assembly with standard tools and clear instructions. Other construction types, such as interlocking log construction, are considerably more complex, and professional installation is strongly recommended.
Practical Installation Considerations
- Minimum two people are required for safe assembly — sauna panels are heavy and awkward to manoeuvre solo
- Smaller saunas (2–4 person): Allow approximately 3–4 days for assembly with two people, excluding site preparation and timber treatment.
- Larger saunas (6-person+): Allow approximately 4–5 days for assembly with two people.
- These timeframes cover structure assembly only — foundation work, electrical connection, and any timber treatment are additional
- These timeframes are based on having carpentry or general building experience, but no previous experience assembling a sauna. Take them as a rough guide, as actual installation times can vary significantly depending on the experience and skill level of the people doing the assembly.
Electrical Work Is Never DIY
Regardless of how capable you are with tools, a licensed electrician is required to:
- Connect the LED lighting
- Install and connect the electric sauna heater
- Run power from the switchboard to the sauna location
This is a legal requirement and is non-negotiable for a high-load appliance. Factor electrician costs into your budget from the outset.
7. Understand the True Cost of an Outdoor Sauna
The advertised price of an outdoor sauna kit is just the starting point. Depending on your setup, additional costs such as the heater, delivery, foundation, installation and electrical work can add significantly to the overall investment.
| Cost Component | Notes |
|---|---|
| Sauna kit price | The advertised price — the starting point |
| Heater | Often sold separately; cost varies depending on the brand, heater and kW |
| Delivery / freight | Can vary substantially, especially for regional or rural locations |
| Foundation | Concrete slab, pavers, or deck if not already in place |
| Installation / assembly | Labour cost if using a professional installer |
| Electrical work | Switchboard to sauna cabling + heater and LED connection |
| Accessories | Bucket, ladle, thermometer, sand timer, backrests, towel hooks |
| Timber treatment | Exterior and interior timber treatment for longevity |
Customers consistently focus on the kit price and are caught off guard by the additional costs of freight, installation, and electrical work. Building a realistic, comprehensive budget before you purchase prevents disappointment — and ensures you're comparing total-cost-of-ownership between suppliers, not just sticker prices.
8. Common Mistakes When Buying an Outdoor Sauna
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Buying too small
A 2-person sauna sounds sufficient until you're actually using it. Size up if you're uncertain.
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Choosing based on price alone
The cheapest sauna kit isn't necessarily the best value. Compare the overall construction and specifications, including the timber species, dimensions, wall and roof thickness, country of origin, glass type and thickness, heater, as well as what is and isn't included in the advertised price. A lower-priced kit may have fewer inclusions or use different materials and specifications, so it's important to compare the full package rather than the headline price alone.
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Forgetting to check electrical requirements
Discovering a three-phase power requirement or a distant switchboard after purchase creates significant unplanned cost.
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Installing on an unsuitable base
Placing a sauna on bare earth, grass, or an uneven surface leads to structural problems and is likely to void your warranty.
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Not verifying kit inclusions
Assuming LED lights, the heater, and accessories are included when they are not is an extremely common and costly assumption.
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Ignoring internal vs. external dimensions
Purchasing based on external footprint and then finding the usable interior is smaller than expected is a frustrating and avoidable mistake.
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Not allowing adequate assembly clearance
Failing to account for the minimum 0.5m clearance needed around the sauna during assembly can cause real problems on installation day.
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Not factoring in the total cost
The advertised kit price is only one part of the overall investment. Before buying, consider the additional costs involved, including freight, site preparation, foundation, electrical work, installation, timber treatment and accessories. These costs can vary depending on your property and whether you choose to complete some of the work yourself.
Frequently Asked Questions — Outdoor Saunas
What should I know before buying an outdoor sauna?
Before purchasing an outdoor sauna, confirm what's actually included in the kit price (heater, LED lights, accessories, freight, and installation are often sold separately). Measure your available outdoor space carefully and ask for internal dimensions, not just external. Verify what foundation type you need and whether one is already in place. Check your electrical supply with a licensed electrician, particularly the available amperage, distance from the switchboard, and whether single or three-phase power is required. Build a budget that accounts for all additional costs — the advertised kit price is rarely the total cost of ownership.
What size outdoor sauna do I need?
This depends on how many people will use it regularly and how you plan to use it. A 2-person sauna suits couples with limited outdoor space, but if lying down is a priority you may find it too small. A 4-person sauna is the most popular residential choice and works well for families and regular entertaining. A 6-person sauna suits larger households but requires a bigger outdoor footprint and a more powerful heater. When in doubt, size up — a sauna that's slightly too large is far less frustrating than one that's too small.
What kind of foundation does an outdoor sauna need?
Any solid, level, hard surface is suitable — concrete slab, flagstone, timber deck, pavers, bricks, or compacted gravel. The key requirement is that the surface is flat, stable, and hard. Never place an outdoor sauna directly on bare earth or grass. Direct ground contact causes structural instability, accelerates timber decay, creates moisture issues, and is likely to void the manufacturer's warranty. If you don't have a suitable foundation in place, factor the cost of creating one into your budget before purchasing.
Do I need an electrician to install an outdoor sauna?
Yes — a licensed electrician is legally required for all electrical work connected to an outdoor sauna, including running cabling from the switchboard, installing and connecting the electric heater, and wiring the LED lighting. This is a legal requirement, not optional. Before purchasing, speak with an electrician to confirm your available amperage, the distance from the switchboard to the sauna location (which affects cable sizing and cost), and whether single or three-phase power is required for the heater you're considering.
How long does it take to assemble a flat-packed outdoor sauna?
For panel-style flat-packed sauna kits, allow approximately 1–2 days for assembly with two people for smaller models (2–4 person), and 4–5 days for larger models (6-person+), assuming carpentry or general building experience. These timeframes cover structure assembly only — foundation work, electrical connection, and timber treatment are additional. Actual times can vary significantly depending on the experience and skill level of the people doing the assembly, so treat these figures as rough guides.
What is the difference between a barrel sauna and a cabin sauna?
Barrel saunas have a cylindrical shape with curved walls, which creates better heat circulation and typically a more efficient heat-up time for the interior volume. They also have a distinctive, compact aesthetic that suits many Australian backyard settings. Cabin saunas have straight walls and a more traditional rectangular footprint, which generally offers more usable bench space per square metre of floor area and can be easier to position against a wall or fence. Browse our barrel sauna range and cabin sauna range to compare available models.
Can I place an outdoor sauna on a timber deck?
Yes — a timber deck is an acceptable foundation for an outdoor sauna, provided it is structurally sound, level, and capable of bearing the weight of the sauna and its occupants. Before installing on an existing deck, confirm the deck's load-bearing capacity with a builder or structural engineer, as a fully assembled sauna can be considerably heavier than typical outdoor furniture. The deck surface should also be treated or sealed to manage moisture from any condensation or rain.
Ready to Find Your Sauna?
Browse the full Harmone outdoor sauna range — barrel saunas, cabin saunas, and matching heaters, with expert guidance to help you choose the right model for your property.