What you could build at NW11 8NP: 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 Golders Green South, Barnet.
112extensions seen within 600 m in the last 10 years
13loft conversions within 600 m in the last 10 years
80.3extensions 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).
Article 4 direction (Article 4 Small Houses in Multiple Occupation (HMO) Area 1): some rights normally allowed have been removed here. Check what it covers with the council before relying on permitted development.
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 Golders Green South.
Move to a home 20 m² bigger (about £1,443,000)
Stamp duty on the new home
£88,050
Estate agent on yours 1.2% + VAT
£18,504
Solicitors, buying and selling
£3,000
Survey
£600
Removals
£1,500
Money gone
£111,654
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
−£94,800
Money gone
−£37,300
On these figures, extending loses about £148,954 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.
Two-storey extension
Approved
Jul 2026
26/2057/HSE
91, Crewys Road, Nw2 2au
Loft or dormer
Refused
Jul 2026
26/2039/HSE
45, West Heath Drive, Nw11 7qg
Rear extension
Approved
Jul 2026
26/1979/HSE
55, Nant Road, Nw2 2al
Loft or dormer
Approved
Jul 2026
26/1857/HSE
40, Crewys Road, Nw2 2aa
Outbuilding or garden room
Approved
Jul 2026
26/1723/HSE
31, Hodford Road, Nw11 8nl
Loft or dormer
Refused
Jun 2026
26/1565/HSE
56, Basing Hill, Nw11 8th
Loft or dormer
Approved
Jun 2026
26/1642/HSE
56, Dunstan Road, Nw11 8ad
Other householder work
Approved
Jun 2026
26/1591/HSE
400a, Finchley Road, Nw2 2hr
Other householder work
Refused
Jun 2026
26/1390/PNV
31, Hodford Road, Nw11 8nl
Loft or dormer
Approved
Jul 2026
26/1100/HSE
61, Basing Hill, Nw11 8tg
Rear extension
Not needed / lawful
Apr 2026
26/0991/PNH
19, West Heath Gardens, Nw3 7tr
Loft or dormer
Approved
May 2026
26/0936/HSE
45, West Heath Drive, Nw11 7qg
Rear extension
Refused
Apr 2026
26/0825/PNH
56, Dunstan Road, Nw11 8ad
Loft or dormer
Refused
Apr 2026
26/0716/HSE
94, Cloister Road, Nw2 2np
Loft or dormer
Approved
Mar 2026
26/0575/HSE
118, Granville Road, Nw2 2fa
Loft or dormer
Approved
Apr 2026
26/0450/HSE
28, West Heath Drive, Nw11 7qh
Outbuilding or garden room
Approved
Mar 2026
26/0366/HSE
150, Granville Road, Nw2 2ld
Two-storey extension
Approved
Mar 2026
26/0163/HSE
55, Nant Road, Nw2 2al
Two-storey extension
Approved
Feb 2026
25/5184/HSE
10, West Heath Avenue, Nw11 7ql
Other householder work
Approved
Mar 2026
25/5126/HSE
18, Helenslea Avenue, Nw11 8nd
Loft or dormer
Approved
Feb 2026
25/5014/HSE
6, Westover Hill, Nw3 7uh
Windows, doors or cladding
Approved
Jan 2026
25/4849/HSE
28, St Albans Lane, Nw11 7qe
Other householder work
Approved
Feb 2026
25/4753/PNS
26, Dunstan Road, Nw11 8aa
Side return or wrap-around
Approved
Dec 2025
25/4661/HSE
805, Finchley Road, Nw11 8dp
Other householder work
Approved
Dec 2025
25/4522/HSE
27, West Heath Gardens, Nw3 7tr
Porch or front extension
Approved
Jan 2026
25/4617/HSE
117, Granville Road, Nw2 2er
Rear extension
Refused
Jan 2026
25/4549/HSE
54, Hodford Road, Nw11 8nj
Rear extension
Approved
Jan 2026
25/4506/HSE
15c, Wycombe Gardens, Nw11 8an
Two-storey extension
Approved
Jan 2026
25/4243/HSE
231, West Heath Road, Nw3 7ub
Outbuilding or garden room
Approved
Jan 2026
25/4001/HSE
30, West Heath Gardens, Nw3 7tr
Basement
Approved
Nov 2025
25/3868/HSE
94, Cloister Road, Nw2 2np
Two-storey extension
Approved
Nov 2025
25/3820/HSE
94, Cloister Road, Nw2 2np
Rear extension
Not needed / lawful
Oct 2025
25/3823/PNH
150, Granville Road, Nw2 2ld
Two-storey extension
Refused
Oct 2025
25/3482/HSE
30, West Heath Drive, Nw11 7qh
Two-storey extension
Approved
Oct 2025
25/3473/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.
–
94% (157)
88%
8 weeks
Basement
77% (13)
82% (92)
83%
8 weeks
Porch or front extension
100% (6)
86% (131)
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.