What you could build at UB1 1BN: 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 Southall West, Ealing.
76extensions seen within 600 m in the last 10 years
2loft conversions within 600 m in the last 10 years
84.8extensions 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 (126,300 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 Southall West.
Move to a home 20 m² bigger (about £613,000)
Stamp duty on the new home
£20,650
Estate agent on yours 1.2% + VAT
£7,344
Solicitors, buying and selling
£3,000
Survey
£600
Removals
£1,500
Money gone
£33,094
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
−£61,800
Money gone
−£4,300
On these figures, extending loses about £37,394 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.
125, Woodlands Road, Ub1 1ej
Rear extension
Not needed / lawful
Dec 2025
254255PALHE
104, Oswald Road, Ub1 1hp
Two-storey extension
Approved
Dec 2025
254173HH
112, St Josephs Drive, Ub1 1rw
Two-storey extension
Approved
Jan 2026
253590HH
46, Randolph Road, Ub1 1bn
Other householder work
Refused
Sept 2025
252644HH
3, Abbotts Road, Ub1 1hs
Side return or wrap-around
Approved
Jun 2025
250437HH
77, The Broadway, Ub1 1la
Other householder work
Approved
Feb 2025
244837PACBSD
77, The Broadway, Ub1 1la
Other householder work
Refused
Sept 2024
242828PACBSD
151, Queens Road, Ub2 5ba
Rear extension
Not needed / lawful
Aug 2024
242717PALHE
50, Grange Road, Ub1 1by
Rear extension
Not needed / lawful
Jul 2024
242306PALHE
73, Park Avenue, Ub1 3aj
Outbuilding or garden room
Approved
Jul 2024
242173HH
48, Grange Road, Ub1 1by
Rear extension
Refused
May 2024
241497PALHE
8, Lewis Road, Ub1 1bt
Rear extension
Not needed / lawful
Apr 2024
241201PALHE
73, Park Avenue, Ub1 3aj
Two-storey extension
Approved
May 2024
241015HH
41, Park Avenue, Ub1 3aj
Other householder work
Refused
May 2024
240469HH
73, Park Avenue, Ub1 3aj
Rear extension
Not needed / lawful
Apr 2024
240933PALHE
9, Grange Road, Ub1 1by
Rear extension
Approved
Apr 2024
240858HH
17, Avenue Road, Ub1 3bl
Rear extension
Approved
Apr 2024
240546HH
17, Avenue Road, Ub1 3bl
Side return or wrap-around
Approved
Mar 2024
240474HH
26, Kingston Road, Ub2 4ap
Rear extension
Approved
Feb 2024
240064HH
53, Townsend Road, Ub1 1hb
Side return or wrap-around
Approved
Feb 2024
232965HH
129, Woodlands Road, Ub1 1ej
Rear extension
Approved
Feb 2024
234874HH
45, Randolph Road, Ub1 1bl
Outbuilding or garden room
Refused
Feb 2024
234484HH
18, Villiers Road, Ub1 3bp
Loft or dormer
Approved
Nov 2023
234071HH
13, Hanson Gardens, Ub1 1bp
Outbuilding or garden room
Approved
Nov 2023
233998HH
72a, South Road, Ub1 1rd
Other householder work
Withdrawn
Nov 2023
233552PATER
51, Townsend Road, Ub1 1hb
Side return or wrap-around
Refused
Sept 2023
231798PALHE
39, Beaconsfield Road, Ub1 1bs
Two-storey extension
Approved
Dec 2023
233503HH
49, First And Second Floors, The Broadway, Ub1 1jy
Other householder work
Approved
Mar 2024
233350PACBSD
29, Villiers Road, Ub1 3bs
Rear extension
Approved
Nov 2023
232861HH
2, Lewis Road, Ub1 1bt
Rear extension
Not needed / lawful
Aug 2023
233050PALHE
8, Lewis Road, Ub1 1bt
Rear extension
Refused
Jul 2023
232146PALHE
29, The Broadway, Ub1 1jy
Other householder work
Refused
Aug 2023
231868PACBSD
39, Beaconsfield Road, Ub1 1bs
Two-storey extension
Approved
Jul 2023
231994HH
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% (76)
88%
8 weeks
Basement
–
81% (52)
83%
10 weeks
Porch or front extension
–
80% (64)
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.