What you could build at BR3 6QJ: 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 Beckenham East & Kelsey Park, Bromley.
50extensions seen within 600 m in the last 10 years
3loft conversions within 600 m in the last 10 years
64.1extensions 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
Mostly flats at this postcode. Flats have no permitted development rights, so almost any extension or loft conversion needs planning permission, and the freeholder's consent under the lease.
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 Beckenham East & Kelsey Park.
Move to a home 20 m² bigger (about £587,000)
Stamp duty on the new home
£19,350
Estate agent on yours 1.2% + VAT
£6,768
Solicitors, buying and selling
£3,000
Survey
£600
Removals
£1,500
Money gone
£31,218
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
−£70,200
Money gone
−£12,700
On these figures, extending loses about £43,918 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.
1, Elwill Way, Br3 3ab
Loft or dormer
Approved
Mar 2025
25/00176/FULL6
55, Kenwood Drive, Br3 6qy
Loft or dormer
Approved
Mar 2025
24/04806/FULL6
106, Bromley Road, Br3 5np
Windows, doors or cladding
Approved
Feb 2025
24/04429/FULL6
1, Ashdown Close, Br3 6tj
Garage conversion or garage
Approved
Dec 2024
24/04167/FULL6
34, Stanley Avenue, Br3 6px
Loft or dormer
Approved
Dec 2024
24/04140/FULL6
74, Manor Way, Br3 3lr
Two-storey extension
Approved
Feb 2025
24/03749/FULL6
35, Hayes Way, Br3 6rj
Windows, doors or cladding
Approved
Nov 2024
24/03624/FULL6
9, Wickham Way, Br3 3aa
Loft or dormer
Refused
Oct 2024
24/02893/FULL6
1, Quinton Close, Br3 6rf
Rear extension
Approved
Jan 2025
24/02734/FULL6
46, Manor Way, Br3 3lj
Windows, doors or cladding
Approved
Jun 2024
24/01403/FULL6
2c, Ridge House, Kemerton Road, Br3 6nj
Loft or dormer
Approved
May 2024
24/00841/FULL6
22, Stanley Avenue, Br3 6px
Basement
Approved
May 2024
24/00819/FULL6
82, Manor Way, Br3 3lr
Loft or dormer
Approved
May 2024
24/00690/FULL6
84, Manor Way, Br3 3lr
Loft or dormer
Refused
Apr 2024
24/00698/FULL6
9, Wickham Way, Br3 3aa
Loft or dormer
Refused
Apr 2024
24/00633/FULL6
36, Crescent Road, Br3 6ne
Other householder work
Approved
Apr 2024
24/00538/FULL6
88, Wickham Road, Br3 6qh
Outbuilding or garden room
Approved
Apr 2024
24/00426/FULL6
20, Crescent Road, Br3 6ne
Other householder work
Approved
Apr 2024
24/00216/FULL6
32, Wickham Road, Br3 5jt
Other householder work
Approved
Mar 2024
24/00087/FULL6
33, Wickham Way, Br3 3ae
Loft or dormer
Approved
Mar 2024
24/00027/FULL6
9, Manor Grove, Br3 5lb
Loft or dormer
Approved
Feb 2024
23/04619/FULL6
38, Overbury Avenue, Br3 6py
Loft or dormer
Refused
Feb 2024
23/04543/FULL6
7, Oakhill Road, Br3 6ng
Two-storey extension
Refused
Jan 2024
23/03879/FULL6
29, Hayes Lane, Br3 6qs
Side return or wrap-around
Approved
Oct 2023
23/03352/FULL6
67, Manor Way, Br3 3ln
Loft or dormer
Refused
Nov 2023
23/02989/FULL6
3, Stanley Avenue, Br3 6pu
Loft or dormer
Approved
Sept 2023
23/02713/FULL6
12, Kepplestone Mews, Br3 6ax
Loft or dormer
Approved
Sept 2023
23/02683/FULL6
34, Overbury Avenue, Br3 6py
Outbuilding or garden room
Approved
Aug 2023
23/02419/FULL6
84, Manor Way, Br3 3lr
Two-storey extension
Approved
Aug 2023
23/02350/FULL6
49, Vine Cottage, Chancery Lane, Br3 6nr
Windows, doors or cladding
Approved
Aug 2023
23/01720/FULL6
8, Spinney Close, Br3 3xa
Loft or dormer
Approved
Jun 2023
23/01592/FULL6
90, Overbury Avenue, Br3 6py
Loft or dormer
Approved
Jul 2023
23/01578/FULL6
54, Wickham Road, Br3 6lt
Rear extension
Approved
Jun 2023
23/01368/FULL6
13, Stanley Avenue, Br3 6pu
Rear extension
Approved
Jun 2023
23/01027/FULL6
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.
80% (5)
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.