Mansard Roof Extensions in East Dulwich

Where in East Dulwich does a mansard roof extension actually get determined?

Every East Dulwich postcode district we draw in, the stock that dominates it and the authority that validates a mansard roof extension there. East Dulwich fees below are the statutory England rates for 2026, not mansard roof extension estimates.

What changes about a mansard roof extension in each part of East Dulwich?

Roof pitch, wall build-up and plot depth change every few East Dulwich streets, and each one changes what a mansard roof extension can achieve at that address.

• East Dulwich (SE22) — mansard roof extension work in East Dulwich means victorian and edwardian terraces. East Dulwich is Victorian and Edwardian terraces. A mansard on a Victorian terrace almost always needs full planning permission throughout SE22. Southwark Council decides the East Dulwich application, and Lordship Lane anchors the East Dulwich location plan.
• Near East Dulwich: Bermondsey (SE1, SE16) — warehouse conversions, Georgian fragments defines Bermondsey, where warehouse conversions, georgian terraces, new-build set what a mansard roof extension can do. Mansards read as original on Georgian terraces across SE1. Any Bermondsey mansard roof extension is validated by Southwark Council, with Bermondsey Street the usual Bermondsey reference point on the site plan.
• Near East Dulwich: Borough (SE1) — Georgian and Victorian terraces, market quarter defines Borough, where georgian and victorian terraces, warehouse conversions set what a mansard roof extension can do. Mansards read as original on Georgian terraces across SE1. Any Borough mansard roof extension is validated by Southwark Council, with Borough Market the usual Borough reference point on the site plan.
• Near East Dulwich: Camberwell (SE5) — mansard roof extension work in Camberwell means georgian villas, victorian terraces. Camberwell is Georgian villas, Victorian terraces. Mansards read as original on Georgian terraces throughout SE5. Southwark Council decides the Camberwell application, and Camberwell Green anchors the Camberwell location plan.
• Near East Dulwich: Peckham (SE15) — Victorian terraces, creative renewal defines Peckham, where victorian terraces, post-war estates set what a mansard roof extension can do. A mansard on a Victorian terrace almost always needs full planning permission across SE15. Any Peckham mansard roof extension is validated by Southwark Council, with Peckham Rye the usual Peckham reference point on the site plan.
• Near East Dulwich: Dulwich Village (SE21) — Georgian and Edwardian villas, Estate-managed defines Dulwich Village, where georgian villas, edwardian villas (dulwich estate) set what a mansard roof extension can do. Mansards read as original on Georgian terraces across SE21. Any Dulwich Village mansard roof extension is validated by Southwark Council, with Dulwich Picture Gallery the usual Dulwich Village reference point on the site plan.
• Near East Dulwich: Rotherhithe (SE16) — a mansard roof extension in Rotherhithe starts from warehouse conversions, post-war estates, new-build, and Rotherhithe reads as warehouse conversions, riverside. Mansards on post-war blocks are a structural and fire-strategy exercise before they are an aesthetic one in SE16. Southwark Council assesses Rotherhithe mansard roof extensions against its own Rotherhithe character guidance, and the location plan we draw for Rotherhithe references Surrey Quays.

How do conservation areas and Article 4 affect a mansard roof extension in East Dulwich?

East Dulwich conservation designations: there are 43 across Southwark Council, Dulwich Village, Peckham Rye, Borough among them. Designation costs a East Dulwich owner the permitted-development route: a mansard roof extension then needs a £548 householder application over 8 weeks, in place of the £249 prior approval route that takes 6 weeks. Peckham Rye is the East Dulwich designation that most often changes a mansard roof extension design.

Article 4 and your East Dulwich mansard roof extension: Article 4 for HMOs borough-wide; additional Article 4 for office-to-residential in Bermondsey and Elephant & Castle. At a SE22 address that matters twice over, because Southwark Council applies the direction unevenly across East Dulwich — we read the East Dulwich policies map for the exact SE22 address before quoting mansard roof extensions.

The building fabric around East Dulwich: Georgian and Regency in Bermondsey and Borough; Victorian terraces in Camberwell and Peckham; Dulwich Estate controlled housing; riverside new-build. Dulwich Estate private planning scheme affects much of SE21 and SE22; Southwark planning for rest of borough; strong heritage context. A mansard roof extension in East Dulwich is scoped against that stock first, because it decides whether the scheme runs as permitted development, a £274 Lawful Development Certificate, or a full £548 application to Southwark Council.

What happens if a East Dulwich property sits on a boundary?

• Bromley — adjoining East Dulwich, with 48 conservation areas centred on BR1. A mansard roof extension on the far side of the East Dulwich line is determined by Bromley Council, so the East Dulwich quote for mansard roof extensions is checked against Bromley guidance before it is issued.
• Tower Hamlets — adjoining East Dulwich, with 58 conservation areas centred on E1. A mansard roof extension on the far side of the East Dulwich line is determined by Tower Hamlets Council, so the East Dulwich quote for mansard roof extensions is checked against Tower Hamlets guidance before it is issued.
• City of London — the City of London boundary runs against Southwark, so a mansard roof extension a street from East Dulwich is decided by City of London Corporation instead. City of London runs 27 conservation areas across EC1 and its neighbours, which is why mansard roof extensions priced for East Dulwich are re-checked against City of London policy whenever the East Dulwich address sits on that edge.
• Lambeth — the Lambeth boundary runs against Southwark, so a mansard roof extension a street from East Dulwich is decided by Lambeth Council instead. Lambeth runs 64 conservation areas across SE1 and its neighbours, which is why mansard roof extensions priced for East Dulwich are re-checked against Lambeth policy whenever the East Dulwich address sits on that edge.

Sources for this East Dulwich mansard roof extension page: borough policies maps and conservation-area registers (2025–26), Royal Mail postcode district boundaries, the Town and Country Planning (Fees for Applications) (England) Regulations, the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended, and the Party Wall etc. Act 1996.