What you could build at SW16 4RP: 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 Norbury East, Croydon.
61extensions seen within 600 m in the last 10 years
4loft conversions within 600 m in the last 10 years
77.5extensions 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 Norbury East.
Move to a home 20 m² bigger (about £565,000)
Stamp duty on the new home
£18,250
Estate agent on yours 1.2% + VAT
£6,912
Solicitors, buying and selling
£3,000
Survey
£600
Removals
£1,500
Money gone
£30,262
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
−£51,000
Money gone
£6,500
On these figures, extending loses about £23,762 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
Jul 2026
26/01858/GPDO
77, Warwick Road, Cr7 7nn
Outbuilding or garden room
Approved
Aug 2026
26/01849/HSE
108, Norbury Avenue, Cr7 8af
Rear extension
Approved
Aug 2026
26/01854/GPDO
120, Warwick Road, Cr7 7ng
Rear extension
Approved
Jul 2026
26/01454/HSE
18, Norbury Court Road, Sw16 4ht
Two-storey extension
Refused
Jul 2026
26/00529/HSE
22, St Stephen'S Crescent, Cr7 7np
Rear extension
Approved
Jun 2026
26/01332/GPDO
21, Kilmartin Avenue, Sw16 4re
Loft or dormer
Approved
Jun 2026
26/01318/LE
86, Kilmartin Avenue, Sw16 4qz
Rear extension
Approved
Jun 2026
26/01214/GPDO
34, Ederline Avenue, Sw16 4sa
Rear extension
Approved
May 2026
26/00919/HSE
1a, Pollards Hill East, Sw16 4ux
Outbuilding or garden room
Approved
May 2026
26/00375/HSE
77, Warwick Road, Cr7 7nn
Loft or dormer
Approved
May 2026
26/00452/HSE
67, Norbury Avenue, Cr7 8al
Rear extension
Approved
May 2026
26/00764/HSE
211, Norbury Avenue, Cr7 8ab
Rear extension
Approved
Mar 2026
26/00395/GPDO
82, Totton Road, Cr7 7qr
Rear extension
Approved
Mar 2026
26/00107/GPDO
38, Ederline Avenue, Sw16 4sa
Rear extension
Approved
May 2026
26/00232/GPDO
67, Norbury Avenue, Cr7 8al
Rear extension
Approved
Feb 2026
26/00137/GPDO
211, Norbury Avenue, Cr7 8ab
Rear extension
Approved
Feb 2026
26/00131/GPDO
171, Norbury Avenue, Cr7 8ap
Rear extension
Approved
Jan 2026
25/04023/GPDO
58, Ederline Avenue, Sw16 4sa
Rear extension
Approved
Jan 2026
25/03862/GPDO
76, Norbury Crescent, Sw16 4la
Rear extension
Approved
Feb 2026
25/03859/HSE
10, Westminster Avenue, Cr7 8br
Rear extension
Approved
Nov 2025
25/03336/GPDO
106, Strathyre Avenue, Sw16 4rq
Rear extension
Approved
Dec 2025
25/03081/HSE
249, Norbury Avenue, Sw16 3rn
Rear extension
Approved
Oct 2025
25/02401/HSE
38, Ederline Avenue, Sw16 4sa
Rear extension
Refused
Nov 2025
25/02561/HSE
225, Norbury Avenue, Cr7 8ab
Rear extension
Approved
Oct 2025
25/02919/GPDO
16, Palmer'S Road, Sw16 4sj
Side return or wrap-around
Approved
Oct 2025
25/02773/HSE
246, Norbury Avenue, Sw16 3rn
Loft or dormer
Approved
Sept 2025
25/02337/HSE
41, Kensington Avenue, Cr7 8bt
Porch or front extension
Approved
Aug 2025
25/02142/HSE
54, Buckingham Avenue, Cr7 8as
Rear extension
Approved
Nov 2025
25/01972/HSE
56, Craignish Avenue, Sw16 4rw
Outbuilding or garden room
Refused
Nov 2025
25/02036/HSE
46, Craignish Avenue, Sw16 4rw
Garage conversion or garage
Approved
Jul 2025
25/01879/HSE
225, Norbury Avenue, Cr7 8ab
Rear extension
Approved
Jul 2025
25/01642/GPDO
19, Braemar Avenue, Cr7 7rj
Loft or dormer
Approved
Jun 2025
25/01322/HSE
183, Norbury Avenue, Cr7 8ap
Rear extension
Approved
May 2025
25/01218/GPDO
83, Melrose Avenue, Sw16 4ru
Rear extension
Approved
May 2025
25/01229/GPDO
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.