Appeal against a refusal of prior approval for a single-storey rear extension

Appeal Allowed (Prior Approval Granted) on 10 May 2023

rear side extension

21 Colbrook Avenue,

Council: London Borough of Hillingdon

In this case, the council had refused to grant prior approval for a 6m-deep, single-storey rear extension to a house.

The council argued that the proposal was not permitted development because it was not just a rear extension, but also a side extension. It based its claim on the fact that the original house had a rear bay window and that the shallow, angled side wall of that window should be considered a side wall for the purposes of their assessment.

This seemed to us to be a completely unfair decision. Happily, the appeal inspector agreed with us that the bay window was not a side wall, that the new extension should count as a rear extension only (and therefore comply with the permitted development regulations) and allowed the appeal.

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