What you could build at UB1 3JB: 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 Park, Ealing.
64extensions seen within 600 m in the last 10 years
6loft conversions within 600 m in the last 10 years
79.5extensions 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 Southall Park.
Move to a home 20 m² bigger (about £665,000)
Stamp duty on the new home
£23,250
Estate agent on yours 1.2% + VAT
£7,848
Solicitors, buying and selling
£3,000
Survey
£600
Removals
£1,500
Money gone
£36,198
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
−£72,000
Money gone
−£14,500
On these figures, extending loses about £50,698 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.
149, Lady Margaret Road, Ub1 2ps
Outbuilding or garden room
Refused
Aug 2026
262283HH
4, Mount Avenue, Ub1 2lh
Rear extension
Not needed / lawful
Jul 2026
262197PALHE
152, Dormers Wells Lane, Ub1 3jb
Loft or dormer
Refused
Jul 2026
262091HH
141, Lady Margaret Road, Ub1 2ps
Other householder work
Approved
Aug 2026
261888HH
27, St Peters Road, Ub1 2tl
Rear extension
Approved
Jul 2026
262006HH
27, Dormers Wells Lane, Ub1 3hx
Side return or wrap-around
Approved
Jul 2026
261946HH
23, Waxlow Crescent, Ub1 2st
Loft or dormer
Approved
Aug 2026
261652HH
17, Manaton Crescent, Ub1 2sy
Outbuilding or garden room
Approved
Jun 2026
261600HH
49, Waxlow Crescent, Ub1 2st
Rear extension
Refused
May 2026
261371PALHE
147, Lady Margaret Road, Ub1 2ps
Rear extension
Not needed / lawful
Apr 2026
261057PALHE
23, Waxlow Crescent, Ub1 2st
Rear extension
Not needed / lawful
Apr 2026
260947PALHE
122, Kings Avenue, Ub6 9dd
Rear extension
Not needed / lawful
Apr 2026
260992PALHE
4, Mount Avenue, Ub1 2lh
Rear extension
Refused
Apr 2026
260699HH
8, Palgrave Avenue, Ub1 2lx
Outbuilding or garden room
Approved
May 2026
260668HH
27, Carlyle Avenue, Ub1 2ln
Loft or dormer
Approved
Apr 2026
260573HH
27, St Peters Road, Ub1 2tl
Rear extension
Refused
Mar 2026
260574PALHE
51, Telford Road, Ub1 3jg
Two-storey extension
Approved
May 2026
260178HH
138, Dormers Wells Lane, Ub1 3jb
Rear extension
Not needed / lawful
Jan 2026
254749PALHE
51, Darwin Drive, Ub1 3jy
Rear extension
Approved
Jan 2026
253584HH
44, Carlyle Avenue, Ub1 2lw
Loft or dormer
Not needed / lawful
Jan 2026
254304CPL
7, Milford Road, Ub1 3qq
Outbuilding or garden room
Refused
Dec 2025
254535HH
7, Milford Road, Ub1 3qq
Outbuilding or garden room
Approved
Jan 2026
254405HH
63, Palgrave Avenue, Ub1 2ly
Rear extension
Not needed / lawful
Dec 2025
254249PALHE
63, Palgrave Avenue, Ub1 2ly
Rear extension
Approved
Dec 2025
254238HH
6, Longridge Lane, Ub1 3jh
Loft or dormer
Refused
Jan 2026
253889HH
15, Edison Drive, Ub1 3js
Rear extension
Approved
Dec 2025
253239HH
105, North Road, Ub1 2jw
Rear extension
Approved
Nov 2025
253514HH
6, Longridge Lane, Ub1 3jh
Rear extension
Refused
Mar 2026
253689HH
6, Palgrave Avenue, Ub1 2lx
Outbuilding or garden room
Approved
Dec 2025
253532HH
19, Burns Avenue, Ub1 2lp
Two-storey extension
Approved
Jan 2026
253389HH
17, Shelley Crescent, Ub1 2lg
Rear extension
Approved
Oct 2025
253311PALHE
4, Edison Drive, Ub1 3js
Rear extension
Not needed / lawful
Sept 2025
253156PALHE
7, Dormers Avenue, Ub1 2sp
Loft or dormer
Approved
Nov 2025
253044HH
6, Longridge Lane, Ub1 3jh
Loft or dormer
Withdrawn
Oct 2025
253061HH
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.