Planning permission for extensions in Scotland

Do you have permitted development rights at all?

This is the first question, and it removes a large share of Glasgow properties before size is even discussed.

What the limits generally control

Where rights do exist, the Order restricts the extension by reference to a small number of measurements. You need every one of them to pass — failing a single test pushes the whole scheme into a full application.

• How far the extension projects beyond the original rear wall of the house.
• The height of the extension, measured separately for eaves and ridge, and whether it exceeds the height of the original roof.
• Proximity to a boundary, with height restrictions applying close to boundaries.
• The proportion of the original garden ground that ends up covered by buildings.
• Whether the extension fronts a road, which is treated far more restrictively than a rear extension.
• The materials used, which must be similar in appearance to the existing house.

The phrase "original house" matters. It means the dwelling as first built or as it stood in 1948, not as you bought it. A previous owner's extension consumes your allowance.

Getting certainty: a Certificate of Lawfulness

If you believe the works are permitted development but want that confirmed in writing, apply to Glasgow City Council for a Certificate of Lawfulness of Proposed Use or Development. It is cheaper and faster than a full application, and it is the document a solicitor will ask for when you sell.

The full householder application route

What you submit

• A location plan to a recognised scale showing the site outlined.
• Existing and proposed floor plans and elevations.
• A site plan showing boundaries, garden ground and the extension footprint.
• The application fee, paid through ePlanning Scotland.

What happens next

The council validates the submission, neighbours are notified, and the application is advertised where required. A planning officer assesses it against the Local Development Plan — daylight and sunlight to neighbours, overlooking, scale relative to the original house, and impact on the character of the area. Determination is targeted at two months from validation.

Common Glasgow refusal reasons

• Loss of daylight to a neighbouring habitable room, most often in dense terraced and tenement streets.
• Overlooking from raised decking or first-floor windows onto a neighbouring garden.
• Overdevelopment of the plot, where too little usable garden ground remains.
• A design that overwhelms the original house, particularly on sandstone properties with a strong street rhythm.

Planning permission is not building warrant

These are two separate approvals with two separate teams and two separate fees. Planning deals with whether the extension should exist and how it looks. A building warrant deals with whether it is structurally, thermally and fire safe. You can hold planning permission and still be legally unable to start work.