What you could build at TW11 8AN: 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 Teddington North, Richmond upon Thames.
83extensions seen within 600 m in the last 10 years
5loft conversions within 600 m in the last 10 years
106extensions 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.
In the The Grove conservation area: permitted development is narrower (for example no side extensions or roof cladding), and demolition and works to trees need consent.
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 Teddington North.
Move to a home 20 m² bigger (about £988,000)
Stamp duty on the new home
£42,550
Estate agent on yours 1.2% + VAT
£11,880
Solicitors, buying and selling
£3,000
Survey
£600
Removals
£1,500
Money gone
£59,530
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
−£97,800
Money gone
−£40,300
On these figures, extending loses about £99,830 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.
17, Michelham Gardens, Tw1 4sd
Rear extension
Under consideration
–
PA26/2476
18, Cambridge Crescent, Tw11 8dy
Other householder work
Under consideration
–
PA26/1980
6, Birch Close, Tw11 8bj
Two-storey extension
Approved
Oct 2026
PA26/1823
33, Cambridge Road, Tw11 8dt
Other householder work
Under consideration
–
PA26/1408
39, Arlington Road, Tw11 8nl
Side return or wrap-around
Under consideration
–
PA26/1412
146, Waldegrave Road, Tw11 8na
Rear extension
Under consideration
–
PA26/1337
42, Twickenham Road, Tw11 8aw
Other householder work
Under consideration
–
PA26/0868
The Coach House, Vicarage Road, Tw11 8ez
Loft or dormer
Under consideration
–
PA26/0703
14, Grove Gardens, Tw11 8ap
Rear extension
Approved
Apr 2026
PA26/0679
4, Twickenham Road, Tw11 8ag
Two-storey extension
Approved
Apr 2026
PA26/0526
71, Elmfield Avenue, Tw11 8bx
Porch or front extension
Approved
Mar 2026
PA26/0611
3, Arlington Road, Tw11 8nl
Side return or wrap-around
Approved
Mar 2026
PA26/0398
66, Cambridge Road, Tw11 8dn
Outbuilding or garden room
Approved
Feb 2026
PA26/0096
32, Watts Lane, Tw11 8hq
Rear extension
Approved
Mar 2026
PA25/4564
17, Michelham Gardens, Tw1 4sd
Rear extension
Approved
Feb 2026
PA25/4449
26, Arlington Road, Tw11 8nj
Rear extension
Approved
Feb 2026
PA25/4385
4, Blenheim Place, Tw11 8nz
Rear extension
Approved
Jan 2026
PA25/4343
37, Cambridge Road, Tw11 8dt
Loft or dormer
Approved
Jan 2026
PA25/3854
15, Grove Terrace, Tw11 8au
Rear extension
Approved
Mar 2026
PA25/4054
11, Watts Lane, Tw11 8hq
Windows, doors or cladding
Approved
Dec 2025
PA25/3572
20, Teddington Park, Tw11 8da
Loft or dormer
Other
Dec 2025
PA25/3502
77, Strawberry Vale, Tw1 4sj
Loft or dormer
Other
Dec 2025
PA25/3359
12, Grove Terrace, Tw11 8au
Rear extension
Approved
Oct 2025
PA25/3222
6, Hawkesley Close, Tw1 4tr
Basement
Other
Nov 2025
PA25/3296
8, Birch Close, Tw11 8bj
Side return or wrap-around
Approved
Sept 2025
PA25/2843
27, Clive Road, Tw1 4sq
Loft or dormer
Approved
Sept 2025
PA25/2588
5, Wades Lane, Tw11 8hf
Rear extension
Approved
Sept 2025
PA25/2530
48, Teddington Park Road, Tw11 8nd
Windows, doors or cladding
Approved
Aug 2025
PA25/2324
71, Elmfield Avenue, Tw11 8bx
Side extension
Approved
Aug 2025
PA25/2120
79, Elmfield Avenue, Tw11 8bx
Rear extension
Approved
Aug 2025
PA25/1866
31, Elmfield Avenue, Tw11 8bu
Outbuilding or garden room
Approved
Jul 2025
PA25/1430
36, Cambridge Road, Tw11 8dn
Rear extension
Approved
Oct 2025
PA25/1464
75, Twickenham Road, Tw11 8al
Loft or dormer
Approved
Jul 2025
PA25/1623
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%
8 weeks
Basement
–
–
83%
9 weeks
Porch or front extension
–
–
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.