House Extension Drawings in Bromley

Where in Bromley does a house extension actually get determined?

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

Which Bromley neighbourhoods suit a house extension best?

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

• Beckenham (BR3) — Edwardian villas, 1930s semi-detached defines Beckenham, where edwardian villas, 1930s semi-detached set what a house extension can do. Edwardian plots here are wider across BR3. Any Beckenham house extension is validated by Bromley Council, with Beckenham Junction the usual Beckenham reference point on the site plan.
• Chislehurst (BR7) — Large 1930s detached, conservation defines Chislehurst, where 1930s detached, edwardian villas set what a house extension can do. Edwardian plots here are wider across BR7. Any Chislehurst house extension is validated by Bromley Council, with Chislehurst Caves the usual Chislehurst reference point on the site plan.
• Bickley (BR1) — a house extension in Bickley starts from 1930s detached, edwardian villas, and Bickley reads as 1930s detached, conservation. Edwardian plots here are wider in BR1. Bromley Council assesses Bickley house extensions against its own Bickley character guidance, and the location plan we draw for Bickley references Bickley station.
• Orpington (BR5, BR6) — 1930s semi-detached, post-war defines Orpington, where 1930s semi-detached set what a house extension can do. 1930s semis here have the deepest rear gardens in the area across BR5. Any Orpington house extension is validated by Bromley Council, with Orpington High Street the usual Orpington reference point on the site plan.
• Petts Wood (BR5) — a house extension in Petts Wood starts from 1930s semi-detached, and Petts Wood reads as 1930s semi-detached, garden suburb. 1930s semis here have the deepest rear gardens in the area in BR5. Bromley Council assesses Petts Wood house extensions against its own Petts Wood character guidance, and the location plan we draw for Petts Wood references Petts Wood station.
• West Wickham (BR4) — 1930s semi-detached defines West Wickham, where 1930s semi-detached set what a house extension can do. 1930s semis here have the deepest rear gardens in the area across BR4. Any West Wickham house extension is validated by Bromley Council, with West Wickham station the usual West Wickham reference point on the site plan.
• Biggin Hill (TN16) — house extension work in Biggin Hill means 1930s semi-detached. Biggin Hill is 1930s semi-detached, rural fringe. 1930s semis here have the deepest rear gardens in the area throughout TN16. Bromley Council decides the Biggin Hill application, and Biggin Hill Airport anchors the Biggin Hill location plan.

Does Bromley planning policy restrict a house extension?

How designation changes a Bromley house extension: Bromley Council maintains 48 conservation areas, including Bromley Town, Chislehurst, Beckenham. Inside any of them a Bromley house extension cannot rely on permitted development, and the route becomes a £548 householder application determined in 8 weeks rather than a £249 prior approval in 6 weeks. Bromley Town sets the tone for Bromley casework.

Bromley permitted development status: there is no borough-wide direction from Bromley Council, so a house extension at a SE20 address is normally still permitted development. We certify that with a £274 Lawful Development Certificate rather than leaving a Bromley sale to argue it later.

The building fabric around Bromley: Large 1930s detached and semi-detached in Chislehurst and Bickley; Edwardian in Beckenham; Victorian in Bromley town; Metropolitan Green Belt covers significant rural-fringe land. Largest London borough by area; substantial Green Belt; conservation areas in most town centres; generally permissive elsewhere. A house extension in Bromley 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 Bromley Council.

Who decides a house extension on the edge of Bromley?

• Lewisham — the Lewisham boundary runs against Bromley, so a house extension a street from Bromley is decided by Lewisham Council instead. Lewisham runs 30 conservation areas across SE3 and its neighbours, which is why house extensions priced for Bromley are re-checked against Lewisham policy whenever the Bromley address sits on that edge.
• Greenwich — adjoining Bromley, with 20 conservation areas centred on SE3. A house extension on the far side of the Bromley line is determined by Greenwich Council, so the Bromley quote for house extensions is checked against Greenwich guidance before it is issued.
• Bexley — adjoining Bromley, with 16 conservation areas centred on DA1. A house extension on the far side of the Bromley line is determined by Bexley Council, so the Bromley quote for house extensions is checked against Bexley guidance before it is issued.
• Croydon — cross the Bromley boundary and Croydon Council takes the house extension instead, applying 24 conservation areas of its own around CR0. We re-price house extensions at the Bromley edge because Croydon policy and Bromley policy rarely align on house extension depth.

Sources for this Bromley house 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.