Can You Put a Sauna in a Garden Room, Garage or Spare Room?

Yes, you can put a sauna in a garden room, garage or spare room. Each of these spaces can provide a practical location for a home sauna, but the room must be prepared correctly.

Before choosing a location, check:

• The sauna’s external dimensions
• The required clearance around it
• Ceiling height
• Flooring and moisture resistance
• Ventilation
• Electrical requirements
• Delivery and assembly access
• The condition and insulation of the room
• Any applicable planning or building regulations

A spare room may be the most convenient option for a compact indoor sauna, while a garage can provide more space and a practical solid floor. A garden room can create a separate wellness area, but it may require additional checks relating to insulation, outdoor electrics and planning restrictions.

The best location depends on your chosen sauna, the structure of your property and how you plan to use the space.

Where Is the Best Place to Put a Home Sauna?

There is no single location that is right for every household.

The best place for a home sauna is usually a dry, accessible and well-ventilated area with a level floor and the correct electrical supply. You should also have enough room to assemble the cabin and safely enter and leave it.

Here is a quick comparison:

Location	Main advantages	Important considerations
Garden room	Creates a separate wellness space and preserves indoor living space	Insulation, damp, outdoor electrics, planning and access
Garage	Often has a solid floor, generous space and easy ground-floor access	Temperature, moisture, stored chemicals, ventilation and cleanliness
Spare room	Convenient, protected from the weather and easy to use year-round	Flooring, ventilation, electrical supply, delivery access and room size

Before making a decision, compare the exact installation requirements of models in the CenturaHeat sauna collection. Indoor, outdoor, traditional, infrared and hybrid saunas can have different placement and power requirements.

Can You Put a Sauna in a Garden Room?

A garden room can be an excellent place for a sauna, particularly if you want a dedicated wellness area away from the main house.

However, a standard timber summerhouse or uninsulated shed should not automatically be treated as a suitable sauna room. The building must be capable of coping with repeated changes in heat, humidity and outdoor temperature.

What Does a Garden Room Need for a Sauna?

A suitable garden room should provide:

• A stable and level base
• A dry, weather-resistant structure
• Appropriate insulation
• Adequate ventilation
• A suitable electrical supply
• Enough internal space and ceiling clearance
• Safe access around the sauna
• Protection from water penetration and condensation

Check that the garden room roof, walls, doors and windows are in good condition. Any existing leaks, damp patches or condensation problems should be dealt with before installing the sauna.

Is an Insulated Garden Room Better?

An insulated garden room is normally more practical than an uninsulated shed.

Insulation helps moderate the temperature around the sauna during colder weather. It can also make the surrounding space more comfortable when changing, resting or cooling down after a session.

The sauna cabin itself is designed to retain heat, but the wider room still needs to remain dry and suitable for the appliance. A poorly insulated garden building may become extremely cold during winter, potentially increasing warm-up time or placing additional demands on the sauna.

The suitability of the building should always be checked against the manufacturer’s installation instructions.

Does a Garden Room Sauna Need Ventilation?

Yes. Ventilation is an important part of planning any garden room sauna.

There are two separate considerations:

1. The ventilation required by the sauna itself
2. The ventilation required by the surrounding garden room

The sauna’s inlet and outlet vents must remain open and positioned according to the manufacturer’s instructions. Do not place the cabin so close to a wall that a required vent becomes blocked.

The garden room must also be able to release residual heat and moisture after use. This could involve opening windows and doors or using suitable mechanical extraction, depending on the building and sauna type.

Ventilation should be designed before installation rather than added as an afterthought.

What Flooring Is Suitable in a Garden Room?

The sauna should stand on a solid, flat and stable surface.

Suitable options may include:

• Concrete
• Properly installed tiles
• Suitable vinyl flooring
• Another solid, heat-appropriate surface approved for the model

Carpet is generally an impractical surface beneath a sauna because it can retain moisture, collect dirt and make it harder to achieve a stable base.

Check the sauna instructions before changing the floor. The base must be able to support the combined weight of the cabin, heater, stones where supplied and users.

Does a Garden Room Sauna Need Planning Permission?

In England, sauna cabins and other garden outbuildings may fall under permitted development rights when certain limits and conditions are met.

The rules can cover matters such as:

• Position within the garden
• Overall building height
• Distance from the property boundary
• The amount of land covered by buildings
• Listed-building status
• Conservation areas and other designated land
• Whether permitted development rights have been restricted

The Planning Portal specifically includes sauna cabins within its guidance for ancillary garden buildings. Read its current guidance on planning permission for outbuildings before beginning work.

The rules shown by the Planning Portal relate primarily to England. Planning systems differ across Wales, Scotland and Northern Ireland, and local restrictions may also apply.

Contact your local planning authority when:

• You live in a listed property
• Your home is in a conservation area or other designated location
• The building will be close to a boundary
• The garden room exceeds permitted size or height limits
• The property is a flat or maisonette
• The building will have another use beyond normal domestic enjoyment
• You are uncertain whether permitted development rights apply

Planning permission and Building Regulations approval are separate matters. Not needing planning permission does not automatically mean that every element of the project is exempt from other regulations.

Can You Put a Sauna in a Garage?

A garage is often one of the most practical places to install a home sauna.

Garages usually offer ground-floor access, more available space and a hard floor. They can be particularly useful for larger traditional or hybrid sauna cabins that may be difficult to move through the house.

However, the garage must be dry, secure and suitable for regular use.

Why Is a Garage a Good Location?

Potential advantages include:

• Concrete or another solid floor
• Fewer concerns about damaging household flooring
• Good delivery access
• More room for assembly
• Space for changing or cooling down
• Easier access to an outside wall for ventilation
• Separation from bedrooms and main living spaces
• The possibility of combining the sauna with a home gym

A garage conversion can create an effective home wellness area, but the room should not be treated as suitable purely because it has enough floor space.

Check the Garage for Damp

Inspect the garage carefully for:

• Water entering beneath the door
• Leaks from the roof
• Damp walls
• Condensation
• Mould
• Poor drainage
• Cracks in the floor
• Signs of previous flooding

Resolve moisture problems before the sauna arrives.

A sauna should not be installed where rainwater, flooding or persistent damp could reach its structure or electrical components.

Does the Garage Need to Be Insulated?

An unheated garage may become very cold in winter and very warm in summer.

The sauna may still be suitable for garage installation when allowed by the manufacturer, but insulating the surrounding room can make it more comfortable and easier to use throughout the year.

Insulation may also help reduce condensation on cold garage surfaces. However, insulation must be installed as part of a properly designed ventilation and moisture-management approach. Simply sealing every gap can trap moisture if there is no reliable way for it to escape.

Keep the Sauna Away from Garage Storage

Many garages are used to store:

• Petrol
• Paint
• Solvents
• Gas cylinders
• Garden chemicals
• Fuel-powered tools
• Cardboard boxes
• Timber
• Flammable liquids

Do not position a sauna next to combustible or hazardous materials. The surrounding area should be cleared, clean and used in line with the sauna manufacturer’s required safety distances.

A garage that is still regularly used for a vehicle may also contain dirt, exhaust residue and chemicals that make it less appealing as a wellness space.

Consider creating a dedicated sauna zone or converting part of the garage properly rather than placing the cabin among general storage.

What Is the Best Garage Flooring for a Sauna?

A sound concrete floor is often a practical option because it is stable and easy to clean.

Before installation, make sure it is:

• Level
• Dry
• Free from major cracks
• Capable of supporting the sauna
• Not affected by regular water ingress
• Finished appropriately for the sauna model

Some homeowners choose to add tiles or suitable flooring over the concrete to make the space more comfortable and easier to maintain.

Do not use loose platforms, unstable blocks or temporary packing materials to compensate for an uneven floor.

Ventilating a Garage Sauna

The garage must have a reliable supply of fresh air and a method of releasing heat and moisture.

Depending on the layout, this may involve:

• Existing air vents
• An opening window
• External wall ventilation
• Mechanical extraction
• Leaving the wider room open after use

Never cover the sauna’s built-in ventilation openings. Follow the model-specific instructions for clearances and airflow.

Can You Put a Sauna in a Spare Room?

A spare bedroom or unused room can accommodate a sauna when there is enough space, suitable flooring, adequate ventilation and the correct power supply.

This can be one of the most convenient locations because the sauna remains protected from outdoor weather and is easy to access throughout the year.

Compact one-person and two-person indoor models may be particularly suitable where floor space is limited.

Measure More Than the Sauna’s Footprint

Do not measure only the width and depth of the cabin.

You may also need space for:

• External control panels
• Electrical connections
• Ventilation openings
• Door movement
• Assembly
• Maintenance access
• Safe entry and exit
• Any required wall or ceiling clearance

Measure doorways, corridors, staircases and turning spaces along the delivery route. A sauna that fits inside the room may still be impossible to transport to it without sufficient access.

Check the packaged component sizes as well as the assembled dimensions.

Can You Put a Sauna on Carpet?

It is usually better to install a sauna on a hard, level and easy-to-clean floor rather than directly on carpet.

Carpet can:

• Retain moisture
• Make cleaning more difficult
• Affect stability
• Trap dust around the base
• Become marked by the cabin’s weight

The correct flooring depends on the model, so follow its installation manual. Do not place a protective sheet or platform beneath the sauna unless the manufacturer confirms that it is suitable.

Protect the Room from Moisture

A self-contained sauna cabin is different from turning the entire spare room into a sauna. Even so, heat and some moisture can enter the surrounding room when the door opens or when the sauna cools down.

The room should be ventilated after use. Watch for:

• Condensation on windows
• Damp patches
• Peeling paint
• Mould
• Persistent humidity
• Moisture collecting around the base

Traditional saunas in which water is placed on heated stones may require greater attention to moisture management than some infrared models. Flooring and ventilation should suit the particular sauna rather than a general assumption about indoor cabins.

Can a Sauna Go Upstairs?

Potentially, but an upstairs installation requires additional planning.

Consider:

• The weight of the assembled sauna
• The weight of the users
• The heater and stones
• The strength and condition of the floor
• Staircase and doorway access
• Electrical cable routing
• Ventilation
• The consequences of moisture reaching rooms below

Seek structural advice when the floor capacity is uncertain, particularly for larger multi-person models.

Ground-floor rooms are often easier because delivery, electrical work and floor assessment tend to be more straightforward.

What Electrical Supply Does a Home Sauna Need?

Electrical requirements differ considerably between sauna models.

Some compact models may use a suitable standard socket, while larger infrared, traditional and hybrid saunas may require a dedicated hardwired supply. Never assume that a sauna can be connected to an existing socket simply because one is nearby.

Check:

• Voltage
• Power rating
• Current requirement
• Whether the sauna is plug-and-play or hardwired
• Required circuit protection
• Cable type and route
• Isolation requirements
• Distance from the consumer unit
• Whether the existing electrical installation has sufficient capacity

For garden rooms and detached garages, the supply may need to run from the main property to the outbuilding. Outdoor and outbuilding electrical work must be designed for the conditions in which it will operate.

Electrical Safety First states that Part P applies to saunas and electrical work in outbuildings such as garages and sheds. Read its advice on electrical safety in gardens and outbuildings.

Use a qualified electrician for any hardwired connection, new circuit, consumer-unit work or electrical supply to an outbuilding. The electrician should assess the individual sauna and property rather than relying on a general estimate.

Extension leads, multi-plug adapters and improvised electrical connections must not be used as substitutes for the required permanent supply.

Garden Room, Garage or Spare Room: Which Should You Choose?

Choose a Garden Room When:

• You want a separate wellness space
• Indoor floor space is limited
• The building is insulated and weatherproof
• You can arrange a compliant electrical supply
• You have checked planning requirements
• You want to combine the sauna with a garden gym or relaxation area

Choose a Garage When:

• You need more room for a larger sauna
• The garage has a suitable solid floor
• Delivery access is important
• You can create a clean, dedicated area
• Damp and temperature issues can be controlled
• Combustible storage can be removed from the area

Choose a Spare Room When:

• Convenience is your main priority
• You want the sauna protected from outdoor weather
• A compact indoor model fits comfortably
• The room has suitable ventilation
• The flooring can be prepared correctly
• The sauna can be delivered through the house

Indoor Sauna or Outdoor Sauna?

Another option is to choose a purpose-built outdoor sauna rather than placing an indoor model inside a separate building.

Indoor Saunas

Indoor saunas are designed to be installed within a protected internal environment. Suitable locations may include:

• Spare rooms
• Home gyms
• Garages
• Large bathrooms
• Dedicated wellness rooms
• Properly prepared garden rooms

An indoor model must not be placed outside unless the manufacturer specifically approves it for outdoor use.

Outdoor Saunas

Outdoor saunas are designed with external conditions in mind. They may include weather-resistant roofs, exterior cladding and structures intended for garden installation.

They still require:

• A suitable base
• Safe electrical work
• Drainage and ventilation
• Appropriate positioning
• Routine exterior maintenance
• Planning checks where relevant

An outdoor-rated sauna may be more suitable than converting an existing garden room when you want a dedicated garden installation.

Pre-Installation Checklist

Complete these checks before ordering your sauna:

Space

• Measure the floor area
• Check ceiling height
• Allow for all required clearances
• Confirm door-opening space
• Leave maintenance access

Delivery

• Measure external gates
• Check doors and corridors
• Measure staircases
• Look for tight corners
• Confirm where the packages will be unloaded

Flooring

• Make sure the surface is level
• Check that it is solid and dry
• Remove unsuitable floor coverings where required
• Consider moisture resistance
• Confirm load capacity if uncertain

Ventilation

• Check the sauna’s inlet and outlet positions
• Do not block built-in vents
• Plan how the wider room will release moisture
• Consider extraction where necessary
• Follow the manufacturer’s instructions

Electrics

• Confirm the sauna’s power rating
• Check whether it is plug-and-play or hardwired
• Ask an electrician to assess the supply
• Plan the cable route
• Do not rely on extension leads

Building Condition

• Repair leaks
• Deal with damp and mould
• Check the roof and walls
• Improve insulation where necessary
• Ensure the area remains secure and weatherproof

Permissions

• Review permitted development limits
• Check local restrictions
• Contact the planning authority when uncertain
• Consider whether Building Regulations approval applies
• Obtain landlord or freeholder permission where required

Common Installation Mistakes to Avoid

Choosing the Location Before the Sauna

Select a model and check its installation requirements before committing to a room. Different saunas can require different clearances, flooring and electrical supplies.

Measuring Only the Finished Cabin

The sauna must also reach the room. Measure the entire delivery route and check the dimensions of the largest packaged panels.

Assuming Every Sauna Uses a Standard Plug

Power requirements vary. Confirm the exact model specification before ordering or arranging electrical work.

Blocking Ventilation Openings

A cabin positioned tightly against a wall may prevent the ventilation system from working as intended.

Installing in a Damp Garden Building

Existing damp or leaks will not be solved by placing a sauna in the room. Repair the structure first.

Using an Indoor Sauna Outdoors

Indoor models are not designed to withstand rain, frost and prolonged exposure to outdoor conditions unless explicitly stated otherwise.

Ignoring the Surrounding Room

The sauna may be self-contained, but the wider room still needs suitable flooring, airflow, access and moisture control.

Leaving Electrical Planning Until Delivery Day

Electrical changes may require a new circuit, cable route or work in the consumer unit. Have the supply assessed before the sauna arrives.

Final Thoughts

A sauna can be installed in a garden room, garage or spare room, but a successful installation depends on much more than whether the cabin physically fits.

The room should be:

• Dry and weatherproof
• Well ventilated
• Structurally suitable
• Large enough for the required clearances
• Fitted with an appropriate floor
• Accessible for delivery and assembly
• Supplied with the correct electrical connection

A garden room can create a peaceful, separate retreat. A garage often offers generous space and practical flooring, while a spare room provides convenience and year-round protection from the weather.

Choose the sauna first, study its installation requirements and then assess each possible location. This reduces the risk of unexpected electrical work, poor ventilation or delivery problems later.

For help selecting the right model for your available space, contact the CenturaHeat team with your room measurements, preferred capacity and proposed installation location.

Frequently Asked Questions

Can you put a sauna in a wooden garden room?

Yes, provided the garden room is dry, weatherproof, stable, ventilated and suitable for the sauna’s electrical and clearance requirements. A basic uninsulated shed may need significant preparation before it is suitable.

Can you put an indoor sauna in a garage?

Yes, an indoor sauna may be installed in a garage when the manufacturer permits it and the garage is dry, ventilated, clean and protected from the weather. The sauna should be kept away from vehicles, fuels, chemicals and combustible storage.

Can you put a sauna in a bedroom?

A sauna can potentially be installed in a spare bedroom when there is enough space, appropriate flooring, ventilation and the required power supply. Consider delivery access and the effects of residual heat and moisture on the room.

Does a home sauna need ventilation?

Yes. Sauna ventilation supports airflow within the cabin, while the surrounding room also needs a way to release moisture and residual heat. Follow the exact vent-placement and clearance instructions for your model.

Does a sauna need a drain?

Not every prefabricated home sauna requires a floor drain. Requirements depend on the design, heater type, usage and manufacturer’s instructions. Do not assume that a drain is needed or unnecessary without checking the specific model.

Does a sauna need a dedicated electrical circuit?

Many larger or higher-powered saunas require a dedicated hardwired circuit, while some smaller models may be designed for a suitable standard socket. A qualified electrician should confirm the requirements.

Can a sauna sit directly on concrete?

A sound, level and dry concrete floor can be a practical base for many sauna cabins. Check the manufacturer’s flooring requirements and repair cracks, damp or uneven sections before installation.

Do you need planning permission for a garden room sauna?

Not always. In England, some sauna cabins and outbuildings may qualify as permitted development, subject to size, height, location and property restrictions. Different rules apply elsewhere in the UK, so check with the relevant local authority.

Can you put a sauna in an unheated garage?

Potentially, when the sauna is approved for the environment and the garage remains dry. Cold conditions may affect comfort and warm-up time, so insulation and ventilation should be considered.

What is the best room for an indoor sauna?

A ground-floor spare room, home gym, prepared garage or dedicated wellness room can work well. The best option is the one that provides sufficient space, suitable flooring, ventilation, safe electrics and straightforward delivery access.