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  • If you are planning to install roof windows or rooflights into your current roof, you need to know where you stand legally. We have a lot of people asking us ‘do I need planning permission for roof windows?’ and this article is designed to give you an idea of the requirements placed upon you.

    Thankfully, the process for installing rooflights is simple and red tape-free, although there are slightly different rules in England, Wales and Scotland. Read on to find out all about planning permission and roof windows and what you need to do.


    Rooflight Rules in England, Wales and Scotland

    When you install windows in a pitched or flat roof, you are making a significant change to the look of the property, and that is why many people believe that they might need planning permission for roof windows. However, this type of home improvement usually fits within the remit of permitted development, which allows homeowners to make alterations such as reroofing and adding rooflights without going through the drawn out processes of the planning system.



    Schedule 2, Part 1, Class C of the The Town and Country Planning (General Permitted Development) (England) Order 2015 sets out the rules about what consists of permitted and not permitted developments in England.

    Essentially, for any development, including installing rooflights, you do not need planning permission if the change:

    ● Doesn’t stand out more than 150 millimetres from the plane of the existing roof slope
    ● Isn’t taller than the height of the existing roof

    In addition, if the window is on a roof slope forming a side elevation of the home it must be obscure-glazed and not able to be opened unless the parts of the window which can be opened are more than 1.7 metres above the floor of the room in which the window is installed.




    The Welsh government’s rules are similar in regards to the maximum length the rooflight can stand out from the existing slope and the development not being taller than the existing roof. It also makes the following additional requirements:

    ● Side facing windows need to be obscure-glazed and non-opening if they are installed in the side elevation of a dwellinghouse that is within 10.5 metres of a side boundary of the house
    ● The appearance of the materials used must, as far as possible, match the appearance of those used on your existing roof
    ● Planning permission is required if the roof light would result in the provision of a roof terrace, whether or not it would incorporate associated railings, fencing or other means of enclosure.



    Scotland also offers permitted development on many projects. The category regarding roof windows in the Scottish government’s ‘Householder Permitted Development Rights: Guidance’ is entitled ‘Any improvement, addition or other alteration to the external appearance of a dwellinghouse that is not an enlargement’. Essentially, as long as a development doesn’t stand more than one metre above the roof, it should fall under the permitted development rules.


    Roof Windows in Conservation Areas

    All three nations agree on the fact that installing roof windows in conservation areas or World Heritage Sites does not come under the permitted development ruling. If you want to change the appearance of your home in these locations, you will have to apply for planning permission for roof windows.

    It is also worth checking with the local planning authority before commencing the project even if you don’t think you live in a conservation area. There are some other locations where permitted development does not apply and your local authority will be able to advise you.


    Building Regulations

    Although you don’t generally need planning permission for rooflights, it is important that you check building regulations when you take on this task. If installing roof windows makes changes to the structure of the roof, as well as the appearance, that requires approval. The regulations bear in mind whether the roof needs strengthening to take the weight of the new window, as well as the energy performance and its fire performance too.


    Want to Install Roof Windows?

    Now you have the answer to the question ‘do I need planning permission for roof windows?’ and you can see the answer is generally ‘no’. However, in all of these types of situations, no two cases are exactly the same. It is always worth talking to your local planning department for reassurance before you begin a project. They will be able to tell you the situation relating to your exact situation and will give you peace of mind that you can browse our range of roof windows and rooflights, and start to get excited about the new project