Roof additions and alterations

Last updated: 12 June 2018

If you want to add extra space to the top floor of your house, you might want to consider adding a dormer.

A dormer is an extension, usually with a window, that sticks out of a sloping roof and gives you a bit more headroom.

Permitted development

Before you arrange to alter or add to your roof, you should first check to see if you need to apply for planning permission.

Many additions or alterations do not need a planning permission application, because most meet a set of rules called 'permitted development'. The permitted development rules are:

  • they are not on the front or side of your house and facing a road
  • the distance between the dormers and the boundary of your curtilage they face is more than 10 metres
  • the development would not be higher than the existing roofline (when measuring the height of the roofline, do not include chimneys)
  • all your dormers combined cover less than half the width of the roof
  • the distance between the dormers and any edge of the roof is at least 30 centimetres
  • it's not within a conservation area

You should always check with your council's planning department to see whether you need to apply for planning permission. Even if you meet the permitted development rules, there may be other approvals you'll need to get.

For more information on what is considered a permitted development when adding to your roof, read the Scottish Government's Guidance on Householder Permitted Development rights publication and go to section 4.42.

Planning permission

If you want to add to your roof but it does not meet the conditions for permitted development, you have to apply for planning permission.

Find out how to apply for planning permission, or contact your local authority for further information.

Other approvals

You might need other approvals before you can carry out work. For example, you might need approval under the building regulations from the local council.

If you do not own the land on which the development is being carried out (for example, if you're a tenant or the land's in joint ownership), you need to get the landowner's permission.

If you live in a listed building you'll also need to obtain listed building consent.

It's your responsibility to make sure you get any necessary approval.