What you could build at BR6 9NJ: 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 Orpington South, Bromley.
46extensions seen within 600 m in the last 10 years
3loft conversions within 600 m in the last 10 years
108.9extensions 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 Orpington South.
Move to a home 20 m² bigger (about £686,000)
Stamp duty on the new home
£24,300
Estate agent on yours 1.2% + VAT
£8,136
Solicitors, buying and selling
£3,000
Survey
£600
Removals
£1,500
Money gone
£37,536
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
−£72,600
Money gone
−£15,100
On these figures, extending loses about £52,636 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.
May 2025
25/00989/FULL6
14, Borkwood Park, Br6 9ld
Rear extension
Not needed / lawful
Apr 2025
25/01174/HHPA
5, Fairview Drive, Br6 9nx
Rear extension
Approved
May 2025
25/01076/FULL6
4, Melrose Crescent, Br6 9nt
Rear extension
Approved
May 2025
25/00775/FULL6
8, Gleeson Drive, Br6 9lj
Loft or dormer
Approved
May 2025
25/00786/FULL6
8, Gleeson Drive, Br6 9lj
Rear extension
Approved
May 2025
25/00787/FULL6
12, Conifer Close, Br6 9qd
Other householder work
Approved
May 2025
25/00717/FULL6
8, Haywood Rise, Br6 9lt
Two-storey extension
Approved
May 2025
25/00656/FULL6
31, North Drive, Br6 9pg
Loft or dormer
Approved
Apr 2025
25/00522/FULL6
14, Kent Close, Br6 7hd
Loft or dormer
Approved
Mar 2025
25/00049/FULL6
7, Warren Avenue, Br6 6hx
Rear extension
Approved
Jan 2025
24/04557/FULL6
8, Haywood Rise, Br6 9lt
Two-storey extension
Refused
Jan 2025
24/04518/FULL6
15, Green Farm Close, Br6 6dj
Two-storey extension
Approved
Jan 2025
24/04380/FULL6
16, Fairview Drive, Br6 9nx
Rear extension
Approved
Jan 2025
24/04290/FULL6
60, Hilborough Way, Br6 7en
Garage conversion or garage
Approved
Jan 2025
24/04253/FULL6
60, Hilborough Way, Br6 7en
Other householder work
Approved
Jan 2025
24/04256/FULL6
30, Ashbourne Rise, Br6 9pz
Porch or front extension
Approved
Jan 2025
24/04223/FULL6
4, Freesia Close, Br6 6nb
Porch or front extension
Approved
Dec 2024
24/03995/FULL6
16, Melrose Crescent, Br6 9nt
Rear extension
Approved
Nov 2024
24/03527/FULL6
13, Melrose Crescent, Br6 9nt
Garage conversion or garage
Approved
Oct 2024
24/03114/FULL6
34, Cleave Avenue, Br6 7hb
Rear extension
Approved
Aug 2024
24/02486/FULL6
46, Southlands Avenue, Br6 9nf
Rear extension
Not needed / lawful
Jul 2024
24/02352/HHPA
13, Oleander Close, Br6 7tq
Loft or dormer
Approved
Aug 2024
24/02022/FULL6
19, Gleeson Drive, Br6 9lj
Side return or wrap-around
Approved
Jul 2024
24/02142/FULL6
30, Gleeson Drive, Br6 9lj
Outbuilding or garden room
Refused
Jul 2024
24/01266/FULL6
19, Ashley Gardens, Br6 9nh
Two-storey extension
Approved
Jun 2024
24/01597/FULL6
6, Borkwood Park, Br6 9ld
Two-storey extension
Approved
May 2024
24/00964/FULL6
3, Conifer Close, Br6 9qd
Other householder work
Approved
Apr 2024
24/00730/FULL6
16, Oakleigh Gardens, Br6 9pl
Two-storey extension
Approved
Apr 2024
24/00713/FULL6
39, Pinewood Drive, Br6 9nj
Loft or dormer
Approved
May 2024
24/00444/FULL6
3, Borkwood Park, Br6 9ld
Rear extension
Approved
Feb 2024
24/00051/FULL6
6, Warren Avenue, Br6 6hx
Windows, doors or cladding
Approved
Feb 2024
23/04785/FULL6
41, Pinewood Drive, Br6 9nj
Other householder work
Approved
Feb 2024
23/04746/FULL6
17, Darwin Close, Br6 7ep
Loft or dormer
Approved
Jan 2024
23/04672/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.
100% (11)
85% (123)
88%
8 weeks
Basement
–
77% (26)
83%
9 weeks
Porch or front extension
86% (7)
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.