Appeal against a refusal of planning permission for a loft conversion with two rear dormers

Appeal Allowed (Full Planning Permission Granted) on 21 June 2023

dormer over outrigger

186 Devonshire Road,
W4 2AW

Council: London Borough of Hounslow

Rear dormer roof extensions are often permitted development, meaning that planning permission is not required at all. But some properties don’t have permitted development rights and some dormer roof designs are not permitted development. So what can you do?

You can apply for full planning permission, but most councils have strict policies requiring that dormers are much smaller than is usually allowed under permitted development.

The London Borough of Hounslow has specific guidance on extensions to a house – their Residential Extension Guidelines Supplementary Planning Document 2017 (SPD). It says that roof extensions should be on the main roof only and set well in from all sides of the roof.

That makes dormers impractically small and makes it very difficult to get a staircase up from the floor below. In this case, our clients wanted a full-sized rear dormer and a dormer over their outrigger (as shown in the image on the left). To Hounslow, that was a big no. The good news is that you always have the right of appeal!

In our Appeal Statement, we pointed out that a large number of the houses on the road and on the road behind had similar rear dormer extensions. We provided details of 14 similar extensions (see of which you can see in the satellite image on the right), all of which were precedents for what our client was proposing.

To further reinforce our case, we found details of appeals in the area where similar arguments had been successful.

In the appeal decision, the inspector agreed with us that the dormers would not cause any harm to the streetscene and that they would be similar to many other developments in the immediate area. He also agreed that there would be no harm to the outlook from neighbouring properties. We were delighted when the appeal was allowed and fully planning permission was granted.

Dormers roof extensions represent allot of our workload. They are a great way to extend your home but sometimes a nightmare to get permission for. We have written about one of our successful appeals in the Telegraph and have also written here about the importance of appealing a refusal of planning permission for a dormer and here about the anomaly that means that dormers are sometimes permitted development and sometimes not.

In this previous success, we wrote about a very unfair decision in which a council refused permission for a dormer even though the neighbours to both sides had the same development!

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