Why the borough boundary changes your South London loft
South London is not one planning market. It is 7 councils applying national permitted-development rules to Victorian and Edwardian terraces, Victorian and Edwardian terraces in Surbiton, Georgian and Victorian terraces, Victorian and Edwardian villas and terraces, interwar semi-detached houses and Victorian terraces — and reading them against local guidance that differs street by street. The same rear dormer, drawn identically, can be lawful in Lambeth and need a full application a mile away in Croydon. That is the 5-point spread in the table below in one sentence.
The roof stock explains much of it. Lofts across the region sit under hipped roofs on the interwar semis, pitched and gabled roofs on the Victorian terraces, pitched and butterfly roofs on the terraces, butterfly and valley roofs behind the terrace parapets, mansard and pitched roofs on the taller stucco streets, pitched and gabled roofs on the terraces and villas, pitched roofs on the villas, butterfly roofs on the terraces, cottage-style roofs in the Garden Suburb and butterfly / valley roofs on the terraces, and each supports a different conversion: a rear dormer where the roof runs front-to-back with a usable rear slope, a hip-to-gable where the roof is hipped and the side is dead space, a mansard where the street already carries them. We survey the roof before we recommend a route, because the geometry — not the brochure — decides what the space becomes.
Protection is the other half. South London holds conservation areas including Addiscombe (Canning and Clyde Roads), Upper Norwood Triangle and Park Hill, where Class B loft rights are removed outright, and 7 of its 7 boroughs layer Article 4 directions on top. Those are street-level designations, not borough-level ones — which is why we check your exact address against them before a line is drawn, and why a regional average is a starting point rather than an answer.
