What you could build at W5 5PZ: 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 St Mary's, Ealing.
146extensions seen within 600 m in the last 10 years
18loft conversions within 600 m in the last 10 years
125.8extensions 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
Mostly flats at this postcode. Flats have no permitted development rights, so almost any extension or loft conversion needs planning permission, and the freeholder's consent under the lease.
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 St Mary's.
Move to a home 20 m² bigger (about £931,000)
Stamp duty on the new home
£36,850
Estate agent on yours 1.2% + VAT
£11,088
Solicitors, buying and selling
£3,000
Survey
£600
Removals
£1,500
Money gone
£53,038
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
−£96,600
Money gone
−£39,100
On these figures, extending loses about £92,138 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.
262339HH
127, The Grove, W5 3sl
Rear extension
Refused
Aug 2026
262363HH
21, The Common, W5 3jb
Loft or dormer
Approved
Aug 2026
262310HH
15, Elm Avenue, W5 3xa
Loft or dormer
Approved
Jul 2026
261814HH
5, Lammas Park Gardens, W5 5hz
Rear extension
Approved
Jul 2026
261769HH
65, The Park, W5 5np
Porch or front extension
Refused
Jun 2026
261608HH
66, The Park, W5 5np
Porch or front extension
Refused
Jun 2026
261707HH
124, The Grove, W5 3sh
Side extension
Approved
Jul 2026
261673HH
22, Queen Annes Gardens, W5 5qd
Rear extension
Approved
Jun 2026
261667HH
19, The Common, W5 3tr
Rear extension
Approved
Aug 2026
261138HH
3, St Matthews Road, W5 3jt
Loft or dormer
Under consideration
–
261339HH
83, Warwick Road, W5 5qe
Loft or dormer
Refused
Jun 2026
261154HH
1, Victoria Terrace, Ealing Green, W5 5qs
Other householder work
Approved
May 2026
260903HH
44, The Grove, W5 5lh
Loft or dormer
Approved
May 2026
260238HH
1, Marlborough Road, W5 5ny
Loft or dormer
Approved
Mar 2026
260074HH
2, St Matthews Road, W5 3jt
Windows, doors or cladding
Approved
Jan 2026
253677HH
19, Delamere Road, W5 3jl
Loft or dormer
Approved
Nov 2025
253727HH
58, Cedar Grove, W5 4ar
Side return or wrap-around
Approved
Nov 2025
253668HH
35, Queen Annes Gardens, W5 5qd
Two-storey extension
Approved
Jan 2026
253241HH
21, Sunnyside Road, W5 5ht
Loft or dormer
Approved
Oct 2025
253068HH
5, Richmond Road, W5 5ns
Rear extension
Approved
Sept 2025
252858HH
7, Elgar Avenue, W5 3ju
Side extension
Approved
Sept 2025
252796HH
14, Church Gardens, W5 4hh
Rear extension
Approved
Sept 2025
252760HH
20, Kenilworth Road, W5 3uh
Loft or dormer
Approved
Aug 2025
252675HH
22, Grove Road, W5 5ds
Windows, doors or cladding
Withdrawn
Sept 2025
252609HH
30, Lammas Park Road, W5 5jb
Loft or dormer
Approved
Nov 2025
252548HH
7, St Marys Place, W5 5ha
Loft or dormer
Approved
Sept 2025
252371HH
1a, St Marys Road, W5 5ra
Rear extension
Approved
Nov 2025
252492HH
6, Willow Road, W5 4pd
Two-storey extension
Withdrawn
Sept 2025
252173HH
6, Willow Road, W5 4pd
Two-storey extension
Approved
Sept 2025
252174HH
3, Lammas Park Road, W5 5jd
Basement
Approved
Sept 2025
252103HH
8, The Park, W5 5ne
Loft or dormer
Approved
Oct 2025
252247HH
30, Ash Grove, W5 4ax
Rear extension
Not needed / lawful
Jul 2025
252085PALHE
57, Disraeli Road, W5 5hs
Rear extension
Approved
Jul 2025
252062HH
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
60% (5)
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.