What you could build at SE25 6DW: 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 Thornton Heath North East, Croydon.
74extensions seen within 600 m in the last 10 years
3loft conversions within 600 m in the last 10 years
104.8extensions 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 Thornton Heath North East.
Move to a home 20 m² bigger (about £586,000)
Stamp duty on the new home
£19,300
Estate agent on yours 1.2% + VAT
£6,912
Solicitors, buying and selling
£3,000
Survey
£600
Removals
£1,500
Money gone
£31,312
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
−£63,600
Money gone
−£6,100
On these figures, extending loses about £37,412 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.
Rear extension
Approved
Jun 2026
26/01093/HSE
79, Auckland Rise, Se19 2dy
Outbuilding or garden room
Approved
Jun 2026
26/00878/HSE
The Chimes, Upper Beulah Hill, Se19 3lg
Loft or dormer
Approved
Jun 2026
26/00474/HSE
13, Howberry Road, Cr7 8hz
Loft or dormer
Refused
Mar 2026
26/00258/HSE
25, Grange Gardens, Se25 6dl
Rear extension
Approved
Mar 2026
26/00170/HSE
124, Moffat Road, Cr7 8pw
Rear extension
Approved
Mar 2026
25/04081/HSE
24, Wharncliffe Gardens, Se25 6dq
Loft or dormer
Approved
Mar 2026
25/02643/HSE
334, Grange Road, Se19 3dq
Rear extension
Approved
Mar 2026
25/03779/HSE
165, South Norwood Hill, Se25 6de
Loft or dormer
Approved
Feb 2026
25/03386/HSE
19, Annsworthy Crescent, Grange Road, Se25 6tf
Two-storey extension
Approved
Apr 2026
25/03328/HSE
25, Grange Avenue, Se25 6dw
Rear extension
Approved
Oct 2025
25/02447/HSE
8, Beulah Hill, Se19 3ls
Other householder work
Approved
Aug 2025
25/01952/HSE
1, Wharncliffe Gardens, Se25 6dg
Loft or dormer
Approved
Jul 2025
25/01676/HSE
246, South Norwood Hill, Se25 6ba
Rear extension
Approved
Jun 2025
25/00806/HSE
Amstel, High View Close, Se19 2ds
Two-storey extension
Approved
Jun 2025
25/01079/HSE
1, Wharncliffe Gardens, Se25 6dg
Loft or dormer
Refused
Apr 2025
25/00736/HSE
95, Livingstone Road, Cr7 8jy
Rear extension
Refused
Apr 2025
25/00139/HSE
49, Auckland Road, Se19 2dr
Rear extension
Approved
Mar 2025
25/00256/GPDO
46, Auckland Road, Se19 2dj
Other householder work
Approved
Feb 2025
24/03689/HSE
4, Auckland Close, Se19 2da
Rear extension
Approved
Mar 2025
24/04330/HSE
24, Auckland Road, Se19 2dj
Loft or dormer
Approved
Mar 2025
24/04321/HSE
129, Burlington Road, Cr7 8pj
Side return or wrap-around
Refused
Jan 2025
24/03773/HSE
124, Moffat Road, Cr7 8pw
Rear extension
Approved
Nov 2024
24/03308/GPDO
43, Falkland Park Avenue, Se25 6sq
Other householder work
Approved
Aug 2024
24/02222/HSE
7, Upton Road, Cr7 8pr
Two-storey extension
Approved
Aug 2024
24/02048/HSE
160, Burlington Road, Cr7 8ph
Loft or dormer
Approved
Aug 2024
24/01938/HSE
21, Kingslyn Crescent, Se19 3dg
Loft or dormer
Refused
Aug 2024
24/02138/HSE
5, Falkland Park Avenue, Se25 6sq
Rear extension
Approved
Apr 2024
24/00771/HSE
43, Falkland Park Avenue, Se25 6sq
Other householder work
Refused
May 2024
24/00740/HSE
15, Kingslyn Crescent, Se19 3dg
Loft or dormer
Approved
May 2024
24/00652/HSE
160, Burlington Road, Cr7 8ph
Rear extension
Approved
Apr 2024
24/00507/HSE
95, Livingstone Road, Cr7 8jy
Rear extension
Approved
Mar 2024
24/00409/GPDO
10, Auckland Close, Se19 2da
Other householder work
Approved
Jan 2024
23/04308/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.