Appeal against a refusal of planning permission for a rear dormer roof extension
This case provides a typical example of a successful appeal against the refusal of planning permission for a rear dormer roof extension.
The appeal related to the top-floor flat within a converted house. Although many of the surrounding houses had been able to construct large rear dormer roof extensions under permitted development rights, flats do not benefit have permitted development rights. As a result, planning permission was required for the proposed works.
The refusal
TThe council refused planning permission on the basis that the proposed dormer did not comply with its adopted Supplementary Planning Document, Residential Design Guidance.
The guidance stated that dormer extensions should be set in by at least one metre from the party wall, should normally be subordinate features of the roof, and should not occupy more than half the width or depth of the roof slope. The council took the view that the proposal failed to meet these requirements and refused the application accordingly.
The appeal
On appeal, we argued that the council had applied its design guidance too rigidly and had failed to properly assess the proposal in its wider context.
We pointed out that the dormer was well designed, proportionate to the host building and roof, and carefully positioned. It was set in from the sides, set down from the ridge and set up from the eaves, and would not be visible from the street.
We also drew attention to the character of the surrounding area, where numerous similar dormer extensions were already present. In addition, we highlighted the inherent inconsistency within the planning system: had the property been a single dwellinghouse rather than a converted flat, a larger dormer could have been constructed under permitted development rights without the need for planning permission at all.
The inspector’s decision
The inspector agreed that the proposed dormer represented good design and was proportionate to the building and its roof. He concluded that the dormer would not be visible from the street and would therefore cause no harm to the character or appearance of the area.
He also accepted that similar dormer extensions were a common feature in the locality and agreed that the proposal would sit comfortably within that context.
The appeal was allowed and full planning permission was granted.
Why this case matters
This appeal illustrates how refusals based on rigid application of local design guidance can be overturned where a proposal is well designed and properly assessed in its context.
It also demonstrates the difficulties faced by owners of flats, who do not benefit from permitted development rights, even where similar dormer extensions on neighbouring houses are entirely lawful.
If planning permission for a rear dormer roof extension has been refused, this case shows that a refusal does not necessarily reflect how an inspector will view the proposal on appeal.
Refused planning permission for a dormer roof extension?
If planning permission for your dormer roof extension has been refused, you may find it helpful to read our guidance on refused planning permission for a dormer roof extension, which explains when an appeal may be worthwhile.
You can also find more information on the appeal process on our main planning appeals page, and visit or our Barnet appeals page for more information on planning appeals in the borough.
For broader guidance on householder planning permission and extensions, see Martin Gaine’s book, How to Get Planning Permission.
