What you could build at SE25 4NF: 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 South Norwood Park, Croydon.
76extensions seen within 600 m in the last 10 years
12loft conversions within 600 m in the last 10 years
107.5extensions 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 South Norwood Park.
Move to a home 20 m² bigger (about £597,000)
Stamp duty on the new home
£19,850
Estate agent on yours 1.2% + VAT
£6,984
Solicitors, buying and selling
£3,000
Survey
£600
Removals
£1,500
Money gone
£31,934
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
−£67,200
Money gone
−£9,700
On these figures, extending loses about £41,634 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.
19, Sunny Bank, Se25 4tq
Rear extension
Approved
Mar 2026
25/03605/HSE
78, Harrington Road, Se25 4ly
Rear extension
Approved
Nov 2025
25/02709/HSE
138, Harrington Road, Se25 4nb
Loft or dormer
Approved
Nov 2025
25/02228/HSE
87, Sandown Road, Se25 4xd
Rear extension
Approved
Aug 2025
25/01590/HSE
78, Chartham Road, Se25 4hp
Loft or dormer
Approved
Jun 2025
25/00976/HSE
93, Sandown Road, Se25 4xd
Loft or dormer
Refused
May 2025
25/00792/HSE
24, Sheringham Road, Se20 7yj
Rear extension
Approved
May 2025
25/00834/FULL6
39, Wheathill Road, Se20 7xq
Loft or dormer
Approved
Mar 2025
25/00086/FULL6
43, Witham Road, Se20 7yb
Other householder work
Refused
Mar 2025
25/00047/FULL6
57, Watcombe Road, Se25 4xa
Rear extension
Approved
Feb 2025
24/03787/HSE
19, Sunny Bank, Se25 4tq
Rear extension
Refused
Dec 2024
24/03707/GPDO
13, Sheringham Road, Se20 7yh
Rear extension
Approved
Dec 2024
24/03990/FULL6
11, Witham Road, Se20 7ya
Rear extension
Approved
Sept 2024
24/02985/FULL6
15, Westgate Road, Se25 4na
Side return or wrap-around
Approved
Sept 2024
24/01493/HSE
31, Sheringham Road, Se20 7yh
Rear extension
Approved
Jun 2024
24/01711/FULL6
4, Westgate Road, Se25 4lz
Loft or dormer
Approved
Jul 2024
24/01198/HSE
105, Marlow Road, Se20 7xw
Other householder work
Approved
May 2024
24/01299/FULL6
19, Lincoln Road, Se25 4hg
Rear extension
Approved
May 2024
24/01145/GPDO
8, Brooklyn Avenue, Se25 4nl
Loft or dormer
Refused
Aug 2024
24/01090/HSE
21, Cromer Road, Se25 4hh
Two-storey extension
Approved
May 2024
24/00990/HSE
27, Harrington Road, Se25 4lu
Rear extension
Approved
May 2024
24/00972/HSE
120, Marlow Road, Se20 7xa
Rear extension
Approved
May 2024
24/00842/FULL6
38, Wheathill Road, Se20 7xh
Rear extension
Approved
Apr 2024
24/00722/FULL6
130, Harrington Road, Se25 4nb
Side return or wrap-around
Approved
Apr 2024
24/00702/HSE
151, Albert Road, Se25 4js
Side return or wrap-around
Approved
Mar 2024
24/00329/HSE
128, Harrington Road, Se25 4nb
Side return or wrap-around
Approved
Jan 2024
23/04614/HSE
25, Sheringham Road, Se20 7yh
Rear extension
Approved
Jan 2024
23/04308/FULL6
78, Harrington Road, Se25 4ly
Side return or wrap-around
Approved
Dec 2023
23/04156/HSE
38, Cambridge Road, Se20 7xl
Other householder work
Refused
May 2024
23/03790/FULL6
73, Witham Road, Se20 7yb
Rear extension
Approved
Nov 2023
23/03388/FULL6
15, Notson Road, Se25 4jz
Loft or dormer
Approved
Sept 2023
23/02749/HSE
132, Marlow Road, Se20 7xg
Rear extension
Approved
Aug 2023
23/02243/FULL6
68, Chartham Road, Se25 4hp
Rear extension
Approved
Aug 2023
23/02371/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
–
74% (57)
83%
8 weeks
Porch or front extension
–
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.