House extension in Edinburgh

The short answer

A house extension adds floor space by building outward or upward, usually needing both planning permission and a building warrant in Scotland unless it falls within permitted development limits. Design, foundations, structure and services all need coordinating, and neighbouring boundaries or shared walls often come into play. Costs vary with size, storey count, ground conditions and finish level, and rise notably for two-storey or structurally complex designs.

What is different in Edinburgh

• In Edinburgh's conservation areas, rear extensions are generally viewed more favourably than those visible from the street, and materials often need to reference the existing building.
• Tenement ground-floor flats considering a rear extension into a shared back green usually need consent from other owners with rights over that ground.
• West Lothian new-build estates often carry planning conditions restricting extensions to preserve spacing between houses, so checking the original permission is worthwhile.
• Sites on sloping ground, common in parts of Edinburgh and the Pentland foothills, can significantly increase foundation costs.

What the project involves

Extensions range from a modest single-storey kitchen extension to a two-storey addition creating extra bedrooms. All involve foundations, structure, roofing, external finish to match or complement the existing house, and extending services such as heating, electrics and drainage.

Consents and regulations in Scotland

Permitted development rights allow some extensions without planning permission, subject to size and position limits that vary by council, but a building warrant is still required for the construction itself. Larger extensions, those close to a boundary, or those in a conservation area typically need planning permission as well.

Sequencing

Design and pre-application discussion, planning permission, building warrant, groundworks and foundations, structure and roof, first-fix services, external finish, then internal fit-out and final inspection.

What commonly goes wrong

Underestimating groundworks cost on sloping or poor-bearing ground, disputes over shared boundaries or drainage with neighbours, and starting work before the building warrant is granted, which can require costly remedial approval.

What it usually costs

Indicative ranges only, to help you judge a quote. They are not an estimate for your property — only the business doing the work can give you that.

• Single-storey extension: cost driven mainly by footprint, foundation type and glazing specification.
• Two-storey extension: a significant step up in cost due to additional structure, but often better value per square metre than a single-storey addition alone.
• Ground conditions: sloping sites or poor soil can add substantially to foundation cost.
• Matching external finish: matching stone, brick or render to an existing period house typically costs more than a contrasting modern finish.

What to do, in order

1. 1Establish whether the extension fits within permitted development or needs planning permission.
2. 2Commission drawings and a structural design suited to the ground conditions.
3. 3Submit planning and building warrant applications and wait for approval before starting work.
4. 4Complete groundworks and structure before weathering in the roof.
5. 5Extend services and complete internal fit-out.
6. 6Arrange final building standards inspection and completion certificate.

When you need a professional

An architect or architectural technologist can develop the design and lead the planning application, while a structural engineer designs foundations and structure, particularly on sloping or shared ground.

Common questions

How long does a house extension take?

A single-storey extension commonly takes three to five months from groundworks to completion; two-storey extensions typically take longer.

What does house extension cost in Edinburgh?

Edinburgh labour rates sit above the Scottish average, and access is the other cost driver: tenement stair access, scaffolding on a busy street and parking permits all add to a quote. Get three written quotes for the same specification before comparing prices.

How do I find a reliable business for house extension in Edinburgh?

Check the business is trading locally, ask for recent Edinburgh addresses you can look at, confirm public liability insurance and any trade registration, and get the quote in writing. Lothian Property lists independent local businesses and passes your enquiry on with your permission — we do not carry out the work ourselves.

Related pages

• Rear extension

  Extending the back of a house, typically to enlarge a kitchen or create open-plan living space.

• Loft conversion

  Turning roof space into usable rooms, from a simple rooflight loft to a full dormer conversion.