Appeal against a refusal of planning permission for a rear dormer roof extension

Appeal Allowed (Full Planning Permission Granted) on 8 May 2024

Barnet Planning Appeal

28 Caddington Road,

Council: London Borough of Barnet

We have written before about the anomaly in the planning system whereby houses have permitted development rights, and can therefore build large rear dormer roof extensions without needing planning permission, but flats do not.

This is the case even if the flat is the top floor of a converted house, and other houses in the street have been able to build roof extensions under permitted development. 

Where planning permission is needed, councils generally apply very strict planning guidance, making it difficult to build the larger box dormers that can be built under permitted development.

An example of a rear dormer

In this case, Barnet’s guidance is set out in the Supplementary Planning Document, Residential Design Guidance (SPD), which states that dormer extensions should be set in by at least 1 metre from the party wall.The SPD also advises such extensions should normally be subordinate features of the roof and should not occupy more than half the width or half the depth of the roof slope. As the appeal scheme would not meet any of these requirements, the council refused planning permission for our client’s proposal.

Although case officers tend to stick rigidly to their guidance, turning the assessment of planning applications into a tick box exercise, appeal inspectors are more likely to take a step back and take other factors into account.

In this case, the inspector agreed with us that the dormer represented good design. He said that it was large but proportionate to the building and the roof. It was set in from the sides, down from the ridge and up from the eaves. He agreed that the dormer would not be visible from the street and would not therefore harm to the streetscene. 

Finally, the inspector agreed that there were lots of other, similar dormers visible in the area and accepted our point that if there were a house, rather than converted into two flats, a larger dormer would be permitted development.

We were delighted when the appeal was allowed and full planning permission was granted. We have written before that we have noticed that appeal inspectors are becoming a lot more flexible when it comes to dormer roof extensions, even when it means overruling local policies and guidance. In our view, this is because large dormers are not such a common sight (because of homeowners exercising their permitted development rights).

If you have been refused planning permission for something similar, please do not hesitate to get in touch.

Check out our appeal page for advice on planning appeals, including our frequently asked questions (at the bottom of the page).

For more on getting planning permission for extensions, check out Martin Gaine’s book, How to get Planning Permission

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