What you could build at N2 0PS: 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 Hampstead Garden Suburb, Barnet.
108extensions seen within 600 m in the last 10 years
11loft conversions within 600 m in the last 10 years
105.2extensions 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.
In the Hampstead Garden Suburb conservation area: permitted development is narrower (for example no side extensions or roof cladding), and demolition and works to trees need consent.
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 Hampstead Garden Suburb.
Move to a home 20 m² bigger (about £1,682,000)
Stamp duty on the new home
£115,590
Estate agent on yours 1.2% + VAT
£21,600
Solicitors, buying and selling
£3,000
Survey
£600
Removals
£1,500
Money gone
£142,290
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
−£109,200
Money gone
−£51,700
On these figures, extending loses about £193,990 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.
86, Brim Hill, N2 0ey
Loft or dormer
Under consideration
–
26/2607/HSE
44, Gurney Drive, N2 0de
Windows, doors or cladding
Approved
Sept 2026
26/2599/HSE
30, Summerlee Avenue, N2 9qp
Rear extension
Not needed / lawful
Jul 2026
26/2299/PNH
36, Huntingdon Road, N2 9du
Loft or dormer
Approved
Jul 2026
26/2184/HSE
30, Summerlee Avenue, N2 9qp
Rear extension
Refused
Jun 2026
26/1799/PNH
55, Summerlee Avenue, N2 9qj
Loft or dormer
Approved
Jun 2026
26/1649/HSE
94, 96, Great North Road, N2 0nl
Other householder work
Approved
May 2026
26/1122/PNV
55, Summerlee Avenue, N2 9qj
Rear extension
Approved
May 2026
26/1048/HSE
8, Aylmer Road, N2 0bx
Rear extension
Not needed / lawful
Apr 2026
26/0930/PNH
54, Huntingdon Road, N2 9du
Loft or dormer
Approved
Apr 2026
26/0821/HSE
10, Winnington Road, N2 0ub
Side extension
Approved
Apr 2026
26/0681/HSE
30, Summerlee Avenue, N2 9qp
Loft or dormer
Withdrawn
Mar 2026
26/0307/HSE
1, Summerlee Gardens, N2 9qn
Loft or dormer
Approved
Feb 2026
26/0028/HSE
24, Cherry Tree Road, N2 9ql
Basement
Approved
Feb 2026
25/5204/HSE
88, Brim Hill, N2 0ey
Rear extension
Refused
Feb 2026
25/5144/HSE
44, Gurney Drive, N2 0de
Loft or dormer
Approved
Feb 2026
25/5124/HSE
4, Trinity Avenue, N2 0lx
Two-storey extension
Approved
Jan 2026
25/4983/HSE
42, Vivian Way, N2 0hz
Loft or dormer
Approved
Feb 2026
25/4650/HSE
13, Leicester Road, N2 9dy
Loft or dormer
Approved
Feb 2026
25/4575/HSE
58, Bancroft Avenue, N2 0as
Rear extension
Approved
Dec 2025
25/4479/HSE
22, Deansway, N2 0jf
Loft or dormer
Approved
Dec 2025
25/4191/HSE
75, Brim Hill, N2 0ez
Loft or dormer
Approved
Dec 2025
25/3723/HSE
49, Baronsmere Road, N2 9qg
Rear extension
Approved
Dec 2025
25/4030/HSE
5, Park Road, N2 8ex
Loft or dormer
Approved
Nov 2025
25/3956/HSE
143, Abbots Gardens, N2 0jj
Two-storey extension
Approved
Oct 2025
25/3785/HSE
7, Howard Walk, N2 0hb
Windows, doors or cladding
Approved
Nov 2025
25/3707/HSE
47, Lincoln Road, N2 9dj
Loft or dormer
Approved
Sept 2025
25/3401/HSE
13, Talbot Avenue, N2 0ls
Rear extension
Approved
Oct 2025
25/3403/HSE
20, Cornwood Close, N2 0hp
Windows, doors or cladding
Approved
Aug 2025
25/2380/HSE
8, Netherfield, The Bishops Avenue, N2 0an
Basement
Approved
Nov 2025
25/2385/HSE
28, Lincoln Road, N2 9dl
Loft or dormer
Approved
Aug 2025
25/2293/HSE
45, Brim Hill, N2 0ha
Loft or dormer
Approved
Jun 2025
25/1943/HSE
50, Brim Hill, N2 0hq
Windows, doors or cladding
Approved
Jun 2025
25/1671/HSE
37, Gurney Drive, N2 0df
Garage conversion or garage
Approved
Jun 2025
25/1666/HSE
143, Abbots Gardens, N2 0jj
Loft or dormer
Refused
May 2025
25/1317/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.
85% (13)
94% (157)
88%
8 weeks
Basement
80% (5)
82% (92)
83%
8 weeks
Porch or front extension
–
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.