Planning permission
Does the location, size, appearance and intended use qualify for permitted development, or need an application?
Read the England checklistGARDEN ROOM GUIDES
Building regulations and safety
Planning, building regulations and electrical safety — the main checks before you order a garden studio.
Guidance checked 24 September 2026.
Two separate questions
Building regulations
Does the construction or installation work need approval, and which safety requirements apply? A planning exemption does not answer this.
Choose the right UK rules
There is no single UK permitted-development checklist. The rules vary across the UK. Choose the guidance for your location and check the full requirements before you build.
England
Use our England checklist, then check restrictions at your address. The boundary height rule is only one of several conditions.
Official householder guidanceWales
Welsh rules include a 2.5-metre limit for flat roofs. Any part within 2 metres of the house must be no higher than 1.5 metres. Siting, boundaries and protected areas also matter.
Welsh Government planning guideWelsh building regulations guide
Scotland
The guidance uses rear-garden coverage and different height rules: up to 4 metres overall, eaves up to 3 metres, and any part within 1 metre of a boundary no higher than 2.5 metres. Listed-building grounds and conservation areas have extra limits. Check separately whether a building warrant is needed.
Scottish Government garden-building guideNorthern Ireland
Use Northern Ireland’s own planning rules and your council’s building control service. Do not apply the England dimensions or exemptions as a UK-wide rule.
NI Direct planning guidanceWhen a small building may be exempt in England
The table below explains when a detached building with no sleeping accommodation may be exempt from building regulations. Planning permission is a separate check.
| Floor area | Usual exemption conditions |
|---|---|
| Up to and including 15 square metres | Detached, with no sleeping accommodation. This exemption has no boundary-distance or material condition. |
| Over 15, up to and including 30 square metres | Detached, single-storey and no sleeping accommodation. At least 1 metre from every boundary, or constructed substantially from non-combustible materials. |
| Over 30 square metres, or sleeping accommodation | These small-building exemptions do not apply. Speak to building control. |
Non-combustible means materials that do not burn. Timber cladding and SIP construction should not be assumed to meet that requirement. Even an exempt structure needs safe design. Confirm the position with building control, including any services.
Source: Local Authority Building Control — small detached buildings
Boundaries, fire breaks & metal cladding
Before choosing the studio’s position, consider its distance from boundaries and nearby buildings, including the location of doors and windows. Planning height limits and building-regulations fire requirements are separate checks.
Where appropriate, we can install metal sheet cladding on a boundary-facing wall as part of a suitably specified construction. Metal sheets over timber or SIPs do not automatically create a fire-resistant wall or make the building substantially non-combustible. Performance depends on the complete wall system, including its structure, insulation, linings, cavities, joints and openings.
Where required, a competent designer should specify suitable fire-resistant construction and cavity barriers to limit fire spreading through hidden gaps, with evidence that the chosen construction provides the required protection. We agree the details for your site and involve building control where approval is required. ThermoWood’s heat treatment is not a fire-retardant treatment.
The one-metre boundary condition does not apply to every small studio; check the exemption table above. Even an exempt building needs to be safely positioned and built.
Sources: GOV.UK — Approved Document B (England) · LABC — outbuilding exemptions
Why we prefer ThermoWood
Thermal modification uses heat and steam to permanently change the timber’s properties. Exterior-grade Thermo-D softwood is typically treated at around 212°C. The treated timber absorbs less moisture. This improves its resistance to decay and reduces swelling and shrinkage as the seasons change. It does not eliminate movement or replace good drainage, ventilation, clearances and maintenance.
We also offer cedar, and can discuss other cladding on request. We agree the cladding material, board shape and finish in your specification, with boundary fire-safety requirements considered separately.
Sources: International ThermoWood Association · Lunawood — thermal modification
Electrics still need proper installation
In England, a garden building sharing the house’s electricity supply remains subject to Part P electrical-safety requirements even if its structure is exempt. BS 7671 is the wiring standard used for electrical design, installation and testing. A new circuit is notifiable work. Agree with the electrician how the work will be notified, and obtain the installation and testing certificates and any required compliance certificate.
For our studios, an electrician installs the internal fittings. Bringing power from the house is arranged separately. Agree who handles the supply, connection, testing and paperwork before work starts.
What “standards” means for your studio
The panel and insulation thicknesses shown on our website are a starting point for the design. They do not, by themselves, confirm building regulations compliance. Your written specification will cover the base, structure, moisture protection, ventilation, glazing and electrical work.
Tell us early if you plan to use heavy equipment, a kiln or heating, or need sound treatment, so these can be considered in the design. Confirm any required approvals before the build.
Keep the paperwork together
Keep the agreed drawings, specification, planning decision or lawful-development certificate if obtained, and relevant building-control and electrical certificates. Check ownership permissions and any separate restrictions affecting the land.
This guide helps you ask the right questions. Your location, property and final design determine what is required.