Does an alteration to a building visible from above but not from surrounding streets and buildings need planning permission?

United Kingdom

This was the point considered recently in Burroughs Day v Bristol City Council where certain roof alterations, whilst plainly affecting the exterior of the building, were not visible from the streets below. Did the alterations amount to a material alteration to the external appearance of the building?

The court took the view that they did not and accordingly that planning permission was not needed - it is the external appearance which matters, but only from the usual vantage points, namely the surrounding streets or neighbouring buildings and not from the air.