What you could build at BR1 3DF: the planning rules at this address, what neighbours have built and how big, planning decisions nearby, rough costs and the value an extension adds, and how to get started. In Bromley South, Bromley.
51extensions seen within 600 m in the last 10 years
3loft conversions within 600 m in the last 10 years
97.4extensions per 1,000 homes in the neighbourhood (10 years)
● work seen on energy certificates · ● application approved · ● refused · ● pending or other · ● this postcode
The rules at this address
Houses usually have permitted development rights: some rear extensions (typically up to 3 m deep for a semi or terrace, 4 m detached), loft conversions within volume limits, and porches can go ahead without planning permission. Larger single-storey rear extensions (up to 6 m / 8 m) can use the “prior approval” neighbour scheme.
Not in a conservation area (from council registers).
No Article 4 direction recorded for this postcode.
Listed buildings need listed building consent for most changes, inside and out: check the National Heritage List.
To be certain work is permitted development, apply for a lawful development certificate (about £129 for householders in England). Building regulations apply either way.
Across England and Wales, homes extended by a typical 30 m² and then resold rose about 11.1% more than similar homes nearby over the same years (124,884 resales). How extensions pay off by size, type and region.
Single-storey rear or side extension: about £2,000–£3,000 per m² (London £2,500–£4,000), plus fees and VAT
Loft conversion: about £45,000–£75,000 for a dormer; more for a mansard or hip-to-gable
Two-storey extension: about £1,800–£2,800 per m² of new floor
Garage conversion: about £15,000–£30,000
Basement: about £3,500–£5,000 per m², London mostly
Build costs are rough 2026 ranges from industry guides, not quotes. Get three quotes for your plans.
Move or improve?
The money you don't get back either way, for the same extra space in Bromley South.
Move to a home 20 m² bigger (about £603,000)
Stamp duty on the new home
£20,150
Estate agent on yours 1.2% + VAT
£7,128
Solicitors, buying and selling
£3,000
Survey
£600
Removals
£1,500
Money gone
£32,378
Extend by 20 m²
Building, plus 15% for design, planning and contingency
£57,500
Less what it adds to your home's value 60% of the local price
−£64,800
Money gone
−£7,300
On these figures, extending loses about £39,678 less. Moving also changes the area, the schools and the commute; extending means months of building work and depends on planning.
Building costs vary a lot (a single-storey rear extension is often £2,000–£3,000 per m², more in London). How much space adds depends on the home and street: what extensions added to resale prices. A guide, not advice; nothing you type leaves this page.
Getting started
Look at what neighbours did. Open applications above to see drawings that were approved on similar houses, and who designed them.
Check the route: permitted development (with a lawful development certificate), prior approval for larger rear extensions, or full householder planning permission.
Get a measured survey and a designer: an architect, an architectural technologist or a designer who handles planning drawings.
Apply (householder permission is about £258 in England; councils aim to decide within 8 weeks).
Building regulations through the council's building control or an approved inspector, and party wall notices to neighbours if you build on or near the boundary.
Choose a builder: written quotes, a contract, staged payments, and check their insurance and references.
From energy certificates: an extension where a later certificate shows more floor space, a loft conversion where roof rooms appear. Certificates come with sales, lettings and some building work, so the year is when it was first seen.
Not every extension shows here. We only see building work when a new energy certificate is lodged, which happens when a home is sold, let or newly built. A loft or extension added since then won't appear, even with planning permission and building control sign-off, because those records aren't published as open data outside London. Missing work doesn't mean missing paperwork.
Under consideration
–
25/00846/FULL6
102, Murray Avenue, Br1 3dl
Loft or dormer
Approved
May 2025
25/01144/FULL6
26, Wendover Road, Br2 9jx
Rear extension
Refused
May 2025
25/01075/FULL6
6, Pinewood Road, Br2 9ad
Outbuilding or garden room
Approved
May 2025
25/01283/FULL6
69, Siward Road, Br2 9jy
Rear extension
Not needed / lawful
Feb 2025
25/00101/HHPA
104, Murray Avenue, Br1 3dl
Two-storey extension
Approved
Feb 2025
24/04632/FULL6
72, Widmore Road, Br1 3bd
Windows, doors or cladding
Refused
Jan 2025
24/04582/FULL6
36, Rochester Avenue, Br1 3dw
Rear extension
Refused
Jan 2025
24/04391/FULL6
50, Sparkes Close, Br2 9ge
Rear extension
Approved
Jan 2025
24/04303/FULL6
42, The Chase, Br1 3df
Loft or dormer
Approved
Jan 2025
24/04292/FULL6
3, Pinewood Road, Br2 9ad
Side return or wrap-around
Approved
Jan 2025
24/04205/FULL6
4, Wanstead Road, Br1 3bl
Rear extension
Approved
Nov 2024
24/03651/FULL6
31, Palace View, Br1 3ej
Other householder work
Under consideration
–
24/03279/FULL6
36, Murray Avenue, Br1 3dq
Other householder work
Approved
Nov 2024
24/02947/FULL6
88, Palace View, Br1 3er
Other householder work
Approved
Jul 2024
24/02169/FULL6
38, Rochester Avenue, Br1 3dw
Loft or dormer
Approved
Jul 2024
24/01783/FULL6
79, Murray Avenue, Br1 3dj
Loft or dormer
Approved
May 2024
24/01310/FULL6
110, Murray Avenue, Br1 3dl
Loft or dormer
Approved
May 2024
24/01054/FULL6
13, Queens Road, Br1 3ea
Windows, doors or cladding
Approved
May 2024
24/01013/FULL6
6, Pinewood Road, Br2 9ad
Rear extension
Approved
Apr 2024
24/00801/FULL6
58, Harwood Avenue, Br1 3du
Windows, doors or cladding
Approved
May 2024
24/00708/FULL6
22, South View, Br1 3dp
Rear extension
Approved
Apr 2024
24/00325/FULL6
34, Siward Road, Br2 9jz
Two-storey extension
Approved
Apr 2024
24/00441/FULL6
117, Palace View, Br1 3ep
Rear extension
Not needed / lawful
Feb 2024
24/00242/HHPA
7, Forde Avenue, Br1 3eu
Outbuilding or garden room
Approved
Feb 2024
23/04752/FULL6
30, Forde Avenue, Br1 3ex
Rear extension
Approved
Feb 2024
23/04905/FULL6
21, 1, Hailing Mews, Wendover Road, Br2 9ju
Loft or dormer
Approved
Jan 2024
23/04685/FULL6
72, Widmore Road, Br1 3bd
Loft or dormer
Approved
Jan 2024
23/04564/FULL6
84, Widmore Road, Br1 3bd
Garage conversion or garage
Approved
Jan 2024
23/04457/FULL6
11, Fernwood Close, Br1 3ez
Garage conversion or garage
Approved
Jan 2024
23/04467/FULL6
32, The Chase, Br1 3df
Loft or dormer
Approved
Apr 2024
23/04143/FULL6
82, Palace View, Br1 3er
Side extension
Approved
Oct 2024
23/04263/FULL6
7, Forde Avenue, Br1 3eu
Rear extension
Not needed / lawful
Nov 2023
23/04030/HHPA
42, Forde Avenue, Br1 3ex
Rear extension
Not needed / lawful
Nov 2023
23/03708/HHPA
Householder applications validated since 2023 within 600 m. The council's page has the drawings, the decision notice and who the agent or architect was. Hover a row for the description. Source: GLA Planning London Datahub.
–
85% (123)
88%
8 weeks
Basement
–
77% (26)
83%
9 weeks
Porch or front extension
–
92% (94)
81%
8 weeks
Share of decided applications approved since 2023 (number decided in brackets). Withdrawn applications aren't counted; many are withdrawn when refusal looks likely.