Do You Need Planning Permission for a Garden Sauna in the UK?

The Two Things You Need to Consider

Before you build, understand these are TWO SEPARATE legal requirements:

1. Planning Permission (from Local Council Planning Department)

This controls what you can build, where you can build it, and how big it can be.

2. Building Regulations (from Building Control)

This controls how you build it — electrical safety, fire safety, structural integrity.

You might need one, both, or (rarely) neither. Let's break it down.

Planning Permission: When You DON'T Need It

Your garden sauna qualifies for permitted development if ALL these apply:

• Size: Floor area under 15 square metres (internal)
• Height: Under 2.5 metres to highest point (or 3m with dual-pitched roof)
• Location: At least 2 metres from any boundary
• Coverage: Total outbuildings cover less than 50% of garden
• Position: Not forward of the principal elevation (front of house)
• Type: Single storey only
• Use: Incidental to enjoyment of the house (not a business)
• Not listed: Property is not a listed building
• Not protected: Not in a conservation area, AONB, National Park, or World Heritage Site

Planning Permission: When You DO Need It

You'll need full planning permission if:

Scenario	Why
Sauna over 15m² floor area	Exceeds permitted development size
Height over 2.5m (flat/mono-pitch roof)	Or over 3m for dual-pitch roof
Within 2m of boundary	Height then limited to 2.5m regardless
Listed building	Always needs consent
Conservation area/National Park	Stricter rules apply
Front garden/forward of house	Not permitted development
Commercial use	Change of use required

Special Cases

Flats/Maisonettes: Permitted development rights often removed. Check with council.

Article 4 Directions: Some councils remove permitted development rights in specific areas. Check your council's planning portal.

Covenants: Your property deeds might restrict outbuildings even if planning law allows them.

Building Regulations: What You Need

Even if you don't need planning permission, you likely need building regulations approval for:

Electrical Work (Part P)

Required: Yes, for any new electrical circuit from your house to the sauna.

You have three options:

1. Hire Part P certified electrician - They self-certify (easiest)
2. Do it yourself + notify Building Control - Pay £300-500 fee
3. Do it yourself + hire electrician for final test/cert - Middle ground

I hired a Part P electrician for the final connection and certification (£380). They inspected my cable run, tested everything, and issued the certificate.

Structural Work (Part A)

Usually not required for small outbuildings under one storey. Your foundations don't need Building Control approval.

Fire Safety (Part B)

Required if: Your sauna is within 1 metre of a boundary. You'll need fire-resistant construction on that side.

If over 1m from boundaries (mine was 2.5m), no special requirements.

Drainage (Part H)

Not required for saunas unless you're adding a shower room with waste water connections.

How to Check If You Need Permission

Step 1: Measure Your Plans

• Internal floor area (length x width)
• Height to highest point
• Distance to all boundaries
• Total area of all garden buildings

Step 2: Check Your Council's Planning Portal

Search: "[Your Council] planning portal" + "permitted development"

Look for:

• Article 4 directions in your area
• Conservation area maps
• Local plan policies on outbuildings

Step 3: Check Your Property Deeds

Download from Land Registry (£3) or check your mortgage documents for restrictive covenants.

Step 4: Free Pre-Application Advice

Most councils offer free informal advice before you build. Email their planning department with:

• Your address
• Proposed sauna dimensions
• Distance from boundaries
• Simple sketch or plan

They'll tell you if you need permission. Get this in writing.

If You Need to Apply for Planning Permission

Cost

Planning application fee: £206 (2026 rate for householder application)

Documents You'll Need

• Completed application form
• Site location plan (1:1250 scale)
• Block plan (1:500 or 1:200 scale)
• Elevation drawings (all four sides)
• Floor plan
• Design & access statement (sometimes)

Timeline

• Decision within 8 weeks (target)
• Can take 10-12 weeks if consultations needed
• 21 days for neighbours to comment

Approval Rate

Small garden buildings have ~85% approval rate if reasonably positioned and sized.

Certificate of Lawful Development (Alternative Route)

Instead of planning permission, you can apply for a Certificate of Lawful Development (Proposed).

Cost: £103 (half the price of planning permission)

Benefit: You get written confirmation your sauna is permitted development. Useful for:

• Peace of mind
• Selling the house later (proves compliance)
• If neighbours might complain

Not Required: Only do this if you want belt-and-braces confirmation.

What About Building Regulations?

When to Notify Building Control

You need Building Regulations approval if:

1. You're doing the electrical work yourself (instead of certified electrician)
2. Sauna is within 1m of boundary (fire safety)
3. Any structural work over 30m²

How to Apply

Option 1: Full Plans Application

• Submit detailed plans before starting work
• Building Control reviews and approves
• Cost: £300-500
• Timeline: 5 weeks for decision

Option 2: Building Notice

• Give 2 days notice before starting work
• Building Control inspects as you build
• Cost: £300-500
• Faster start, but less certainty

Option 3: Use Competent Person Scheme

• Hire Part P certified electrician
• They self-certify the work
• No Building Control fee
• Simplest route (this is what I did)

Common Mistakes to Avoid

1. "I'll build it and ask forgiveness later"

Risk: Council can issue enforcement notice requiring removal. Costs you £20,000+ to remove it.

2. "My neighbour has one, so I can too"

Problem: They might have planning permission, or theirs is non-compliant too. Check your own situation.

3. "The builder said I don't need permission"

Issue: Builders aren't planners. If they're wrong, YOU are liable, not them. Check yourself.

4. "No one will notice"

Reality: Neighbours can report it years later. Council can take enforcement action for up to 4 years after completion (or 10 years if they can prove you concealed it).

5. "I'll just call it a shed"

Won't work: Planning officers know the difference. A shed doesn't need 6kW electrical supply.

Scotland, Wales & Northern Ireland

This guide covers England only. Different rules apply in:

Scotland

• Permitted development: Up to 19m² (not 15m²)
• Contact: Local Planning Authority
• Building warrant always required for electrical work

Wales

• Similar to England but stricter in some areas
• More restrictions in conservation areas

Northern Ireland

• Different planning system entirely
• Contact: Planning Service NI

Real-World Examples

Case 1: Simple Approval (My Build)

• Size: 2.4m x 2.1m (5.04m²)
• Location: 2.5m from boundary
• Height: 2.3m
• Needed: Nothing from planning, Part P electrician certificate only
• Cost: £380 (electrician)

Case 2: Needed Planning Permission

• Size: 4m x 4m (16m²) - over limit
• Had to apply for planning permission
• Approved in 7 weeks
• Cost: £206 (planning) + £450 (drawings) + £380 (electrician) = £1,036

Case 3: Rejected Application

• 3m high sauna, 1m from boundary
• Neighbour objected (loss of light)
• Council rejected
• Had to redesign to 2.3m height, 2.5m from boundary
• Resubmitted under permitted development (free)

Quick Decision Flowchart

Is your property a listed building or in a conservation area?

→ YES: Contact planning officer before doing anything

→ NO: Continue...

Is your sauna under 15m² internal floor area?

→ NO: Need planning permission

→ YES: Continue...

Is it under 2.5m high (or 3m if dual-pitched roof)?

→ NO: Need planning permission

→ YES: Continue...

Is it at least 2m from all boundaries?

→ NO: Need planning permission

→ YES: Continue...

Will it be forward of your house frontage?

→ YES: Need planning permission

→ NO: Continue...

Do your existing outbuildings already cover more than 50% of your garden?

→ YES: Need planning permission

→ NO: No planning permission needed!

For electrical work:

→ Use Part P certified electrician (simplest)

→ OR notify Building Control before starting (£300-500)

Final Thoughts

Most people overthink this. If your sauna is:

• Reasonably sized (under 15m²)
• Reasonably positioned (2m+ from boundaries)
• Reasonably height (under 2.5m)

...you almost certainly don't need planning permission. Just use a qualified electrician and you're done.

The planning system is designed to be flexible for small garden buildings. Work with it, not against it, and you'll be absolutely fine.

← Back to Home