Mansard Roof Extensions in Croydon

Where in Croydon does a mansard roof extension actually get determined?

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

Which Croydon neighbourhoods suit a mansard roof extension best?

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

• Selhurst (SE25) — mansard roof extension work in Selhurst means edwardian terraces. Selhurst is Edwardian terraces. Edwardian parapets give a mansard a clean base line throughout SE25. Croydon Council decides the Selhurst application, and Selhurst Park anchors the Selhurst location plan.
• Croydon (CR0) — a mansard roof extension in Croydon starts from edwardian terraces, post-war flats, and Croydon reads as post-war centre, Edwardian residential ring. Edwardian parapets give a mansard a clean base line in CR0. Croydon Council assesses Croydon mansard roof extensions against its own Croydon character guidance, and the location plan we draw for Croydon references Whitgift Centre.
• Crystal Palace (SE19) — Victorian villas, hill character defines Crystal Palace, where victorian villas, edwardian terraces set what a mansard roof extension can do. A mansard on a Victorian terrace almost always needs full planning permission across SE19. Any Crystal Palace mansard roof extension is validated by Croydon Council, with Crystal Palace Park the usual Crystal Palace reference point on the site plan.
• Upper Norwood (SE19) — Victorian villas defines Upper Norwood, where victorian villas, edwardian terraces set what a mansard roof extension can do. A mansard on a Victorian terrace almost always needs full planning permission across SE19. Any Upper Norwood mansard roof extension is validated by Croydon Council, with Upper Norwood Triangle the usual Upper Norwood reference point on the site plan.
• South Norwood (SE25) — mansard roof extension work in South Norwood means victorian terraces. South Norwood is Victorian terraces. A mansard on a Victorian terrace almost always needs full planning permission throughout SE25. Croydon Council decides the South Norwood application, and South Norwood Lake anchors the South Norwood location plan.
• Thornton Heath (CR7) — a mansard roof extension in Thornton Heath starts from edwardian terraces, and Thornton Heath reads as Edwardian terraces. Edwardian parapets give a mansard a clean base line in CR7. Croydon Council assesses Thornton Heath mansard roof extensions against its own Thornton Heath character guidance, and the location plan we draw for Thornton Heath references Thornton Heath station.
• Purley (CR8) — mansard roof extension work in Purley means 1930s semi-detached, edwardian villas. Purley is 1930s semi-detached, Edwardian villas. Edwardian parapets give a mansard a clean base line throughout CR8. Croydon Council decides the Purley application, and Purley Way anchors the Purley location plan.

What local planning policy applies to a mansard roof extension in Croydon?

Croydon conservation designations: there are 24 across Croydon Council, South Norwood, Crystal Palace, Old Coulsdon among them. Designation costs a Croydon 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. Old Coulsdon is the Croydon designation that most often changes a mansard roof extension design.

No blanket Article 4 over Croydon: Croydon Council has not withdrawn permitted development across Croydon, so a mansard roof extension outside a Croydon conservation area usually keeps it. The £274 Lawful Development Certificate is still the document a SE19 owner wants on file.

Croydon housing stock: Victorian villas in Upper Norwood and Crystal Palace; Edwardian terraces in Thornton Heath and Selhurst; 1930s semi-detached in Purley and Coulsdon; post-war in Croydon central. Large, mixed-density outer borough; permissive in outer areas; heritage controls in conservation pockets; major regeneration in central Croydon. Read that before choosing a mansard roof extension route in Croydon — construction, not postcode, sets what is achievable. Croydon Council charges £548 for a householder application and has 8 weeks to determine it.

Who decides a mansard roof extension on the edge of Croydon?

• Sutton — cross the Croydon boundary and Sutton Council takes the mansard roof extension instead, applying 17 conservation areas of its own around SM1. We re-price mansard roof extensions at the Croydon edge because Sutton policy and Croydon policy rarely align on mansard roof extension depth.
• Merton — the Merton boundary runs against Croydon, so a mansard roof extension a street from Croydon is decided by Merton Council instead. Merton runs 28 conservation areas across SW16 and its neighbours, which is why mansard roof extensions priced for Croydon are re-checked against Merton policy whenever the Croydon address sits on that edge.
• Lambeth — adjoining Croydon, with 64 conservation areas centred on SE1. A mansard roof extension on the far side of the Croydon line is determined by Lambeth Council, so the Croydon quote for mansard roof extensions is checked against Lambeth guidance before it is issued.
• Bromley — adjoining Croydon, with 48 conservation areas centred on BR1. A mansard roof extension on the far side of the Croydon line is determined by Bromley Council, so the Croydon quote for mansard roof extensions is checked against Bromley guidance before it is issued.

Sources for this Croydon 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.