Do I need planning permission for an extension in Scotland?
Not always. Scotland's householder permitted development rights allow some extensions to a house without a planning application, provided they stay within limits on position, height and size, and the house isn't in a conservation area, listed, or subject to a condition or direction removing those rights. If an extension doesn't meet every limit, it needs planning permission through a householder application, which costs £371 from April 2026.
Scottish rules are different from England's. Use Scottish guidance, not an English calculator or planning portal.
A modest single-storey extension at the back of a house outside a conservation area is often permitted development. Anything forward of the front, two storeys near a boundary, or on a listed building or in a conservation area usually needs planning permission. Either way, you will probably need a Building Warrant.
What size of single-storey extension is permitted development?
Single-storey ground-floor extensions fall under Class 1A of the Town and Country Planning (General Permitted Development) (Scotland) Order. The extension is not permitted development if:
- any part is forward of the principal elevation, or of a side elevation that fronts a road;
- it is within 1 metre of the boundary and projects more than 3 metres beyond the rear wall of a terraced house, or 4 metres for any other house;
- its eaves are higher than 3 metres, or its overall height is more than 4 metres;
- it would more than double the ground area covered by the original house;
- it would cover more than 50% of the front or rear garden ground, together with other development there;
- the house is in a conservation area.
Can a two-storey extension be permitted development?
Sometimes, under Class 1B, but the limits are tighter. An extension of more than one storey is not permitted development if:
- any part is forward of the principal elevation or a side elevation fronting a road;
- any part is within 10 metres of the boundary of the garden;
- it is higher than the existing house, excluding chimneys;
- it would more than double the original ground area, or cover more than 50% of the front or rear garden;
- the house is in a conservation area.
The 10-metre rule means that, on most suburban plots, a two-storey extension needs planning permission.
| Single storey (Class 1A) | More than one storey (Class 1B) | |
|---|---|---|
| Position | Not forward of the front, or of a side facing a road | Not forward of the front, or of a side facing a road |
| Near the boundary | Within 1m: no more than 3m (terrace) or 4m (other) beyond the rear wall | No part within 10m of the boundary |
| Height | Eaves up to 3m, overall up to 4m | No higher than the existing house |
| Area | No more than double the original footprint, and no more than 50% of the front or rear garden | |
| Conservation area | Not permitted development | |
Porches have their own class: up to 3 square metres, no higher than 3 metres, not within 2 metres of a boundary with a road, and not in a conservation area. The full rules and diagrams are in the Scottish Government's Circular 1/2024 on householder permitted development rights.
When don't permitted development rights apply?
- Conservation areas. Extensions under Classes 1A and 1B are not permitted development, so you need planning permission.
- Listed buildings. You need listed building consent for an extension, whatever its size, and usually planning permission. See extending a listed building.
- Flats. Householder rights for flats are different and more limited than for houses.
- Conditions and directions. A planning condition on a newer house, or an Article 4 direction made by the council, can remove permitted development rights. Check the original planning permission for your house.
- National Parks and other designations. Some rights are restricted in designated areas. See building in the National Park.
Can I extend a flat without planning permission?
Rarely. Householder permitted development rights for flats are much narrower than for houses, and most extensions to a flat, including ground-floor flats with their own garden, need planning permission. You will usually also need the agreement of the other owners under the title deeds, and the Building Warrant may involve shared structure. Check Circular 1/2024, which deals with flats separately.
How can I be sure an extension is permitted development?
Measure carefully against each limit, including the original footprint of the house, which means as it was first built or as it stood on 1 July 1948 for older houses, not including later extensions. If there is any doubt, you can apply to the council for a certificate of lawfulness of proposed use or development. It costs half the normal planning fee and gives you formal confirmation, which is useful when you sell.
What does a householder planning application involve?
- Drawings: a location plan, a site plan, and existing and proposed plans and elevations.
- The form and fee: submitted online through ePlanning, with the £371 fee.
- Neighbour notification: the council notifies neighbours, who can comment.
- Assessment: the council looks at design, scale, privacy, daylight and overshadowing, often using its own householder guidance. Stirling Council, for example, consulted on draft householder alterations and extensions guidance in 2024.
- Decision: the statutory period for a householder application is two months.
If it is refused, you can ask the council's Local Review Body to review the decision. A review fee applies.
What do planners look for in an extension?
- Scale: an extension that is clearly smaller than the house and doesn't overwhelm it.
- Design: either matching the house closely, or a well-considered contrast in quality materials.
- Privacy: windows, balconies and raised terraces that don't overlook neighbouring windows or gardens.
- Daylight and overshadowing: the effect on neighbours' windows and gardens, often tested with the council's own rules of thumb.
- Garden ground and parking: enough outdoor space left, and parking where the council requires it.
Pre-application advice, or an early conversation with the case officer, can resolve most of these before you submit.
Do I need to tell my neighbours?
For a planning application, the council notifies neighbours itself. For permitted development there is no formal notice, but telling neighbours early avoids surprises. Scotland has no equivalent of England's Party Wall Act. If your builder needs access to a neighbour's land, or the work affects a shared wall or boundary, you need the neighbour's agreement, and your title deeds may contain relevant conditions, so take advice from your solicitor.
Do I still need a Building Warrant?
Almost certainly. Permitted development removes only the need for planning permission. Most extensions still need a Building Warrant, which covers structure, fire safety, insulation, ventilation and drainage, and must be granted before work starts. See Building Warrant vs planning permission and Building Warrant fees.
How we help
ED Design is an architectural design studio in Stirling. We check whether an extension can be permitted development, prepare householder planning and Building Warrant applications, and design extensions that work with the house. See our extensions and renovations service and our work in Stirling, Dunblane and Bridge of Allan.
Sources: The Town and Country Planning (General Permitted Development) (Scotland) Amendment Order 2011, schedule (Classes 1A to 1C); Scottish Government: Planning Circular 1/2024, householder permitted development rights; The Town and Country Planning (General Permitted Development) (Scotland) Amendment Order 2024; mygov.scot: adding an extension to your house; Fife Council: scale of planning fees, April 2026; Stirling Council: planning guidance. Last reviewed November 2026.
Questions
Do I need planning permission for an extension in Scotland?
Not always. A single-storey extension at the back of a house can be permitted development if it meets the Class 1A limits and the house isn't in a conservation area or listed. Otherwise you need a householder planning application, £371 from April 2026.
How big can a single-storey extension be without planning permission in Scotland?
Up to 4 metres high with eaves up to 3 metres. Within 1 metre of a boundary it can project no more than 3 metres beyond the rear wall of a terraced house, or 4 metres for other houses, and it can't more than double the original footprint or cover more than half the garden.
Can I build a two-storey extension without planning permission?
Only if no part is within 10 metres of the boundary and it meets the other Class 1B limits, so most two-storey extensions need planning permission.
Do I need a Building Warrant for an extension?
Almost always, even when planning permission isn't needed.
Is there permitted development in a conservation area?
Not for extensions under Classes 1A and 1B. Extensions in a conservation area need planning permission.
General guidance for Scotland, not legal, tax, financial or planning advice for your project. Rules change, so check current official guidance and take advice specific to your site before acting.
