What you could build at CR5 2LB: 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 Coulsdon, Croydon.
26extensions seen within 600 m in the last 10 years
2loft conversions within 600 m in the last 10 years
57extensions 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 Coulsdon.
Move to a home 20 m² bigger (about £610,000)
Stamp duty on the new home
£20,500
Estate agent on yours 1.2% + VAT
£7,344
Solicitors, buying and selling
£3,000
Survey
£600
Removals
£1,500
Money gone
£32,944
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
−£60,000
Money gone
−£2,500
On these figures, extending loses about £35,444 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.
25/04066/HSE
48, Byron Avenue, Cr5 2jr
Two-storey extension
Approved
Apr 2026
26/00487/HSE
96, Coulsdon Road, Cr5 2lb
Side extension
Approved
Mar 2026
25/04054/HSE
38, Coulsdon Rise, Cr5 2sb
Rear extension
Withdrawn
Mar 2026
26/00228/GPDO
36, Coulsdon Road, Cr5 2la
Rear extension
Approved
Mar 2026
25/03684/HSE
6, Ashcroft Rise, Cr5 2ss
Side extension
Approved
Mar 2026
25/04093/HSE
44, Byron Avenue, Cr5 2jr
Two-storey extension
Approved
Nov 2025
25/03150/HSE
32, Coulsdon Rise, Cr5 2sb
Side extension
Approved
Nov 2025
25/03014/HSE
148, Coulsdon Road, Cr5 2le
Other householder work
Approved
Oct 2025
25/02357/HSE
68, Hartley Old Road, Cr8 4hj
Rear extension
Approved
Oct 2025
25/02485/HSE
4, Stoneyfield Road, Cr5 2hj
Rear extension
Approved
Oct 2025
25/02658/HSE
48, Byron Avenue, Cr5 2jr
Rear extension
Approved
Oct 2025
25/02222/HSE
23, Byron Avenue, Cr5 2js
Rear extension
Approved
Sept 2025
25/02266/HSE
62, Coulsdon Rise, Cr5 2sb
Loft or dormer
Approved
Jul 2025
25/01506/HSE
44, Byron Avenue, Cr5 2jr
Rear extension
Approved
Aug 2025
25/00645/HSE
17, Coulsdon Road, Cr5 2lj
Loft or dormer
Approved
Jun 2025
25/01272/HSE
4, Stoneyfield Road, Cr5 2hj
Rear extension
Approved
May 2025
25/00810/HSE
46, Byron Avenue, Cr5 2jr
Porch or front extension
Approved
May 2025
25/00704/HSE
7, Stoneyfield Road, Cr5 2hp
Loft or dormer
Approved
Feb 2025
24/04166/HSE
62, Coulsdon Rise, Cr5 2sb
Basement
Refused
Nov 2024
24/03287/HSE
17, Byron Avenue, Cr5 2js
Two-storey extension
Approved
Oct 2024
24/02677/HSE
44, Byron Avenue, Cr5 2jr
Two-storey extension
Approved
Sept 2024
24/02027/HSE
7, Stoneyfield Road, Cr5 2hp
Loft or dormer
Approved
Oct 2024
24/02261/HSE
44, Byron Avenue, Cr5 2jr
Rear extension
Approved
Jul 2024
24/01894/GPDO
39, Stoneyfield Road, Cr5 2hp
Loft or dormer
Refused
Jul 2024
24/01603/HSE
174, Coulsdon Road, Cr5 2lf
Two-storey extension
Approved
Jul 2024
24/01477/HSE
126, Coulsdon Road, Cr5 2le
Loft or dormer
Approved
Mar 2024
23/04728/HSE
144, Coulsdon Road, Cr5 2le
Loft or dormer
Approved
Nov 2023
23/03275/HSE
25, Coulsdon Court Road, Cr5 2ll
Loft or dormer
Approved
Mar 2024
23/02508/HSE
5, Ashcroft Rise, Cr5 2ss
Rear extension
Approved
Jul 2023
23/02275/GPDO
53, Byron Avenue, Cr5 2js
Two-storey extension
Refused
Jul 2023
23/01777/HSE
51, Coulsdon Rise, Cr5 2sf
Loft or dormer
Approved
Sept 2023
23/01721/HSE
51, Coulsdon Rise, Cr5 2sf
Two-storey extension
Refused
Mar 2023
23/00307/HSE
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.
–
88% (122)
88%
8 weeks
Basement
80% (5)
74% (57)
83%
8 weeks
Porch or front extension
75% (8)
88% (65)
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.