What you could build at TW11 9AH: 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 Central, Richmond upon Thames.
123extensions seen within 600 m in the last 10 years
17loft conversions within 600 m in the last 10 years
105.3extensions 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
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 Teddington Central.
Move to a home 20 m² bigger (about £1,055,000)
Stamp duty on the new home
£49,250
Estate agent on yours 1.2% + VAT
£12,672
Solicitors, buying and selling
£3,000
Survey
£600
Removals
£1,500
Money gone
£67,022
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
−£105,000
Money gone
−£47,500
On these figures, extending loses about £114,522 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.
–
PA26/0617
34, Bolton Gardens, Tw11 9ay
Basement
Under consideration
–
PA26/1820
157, Park Road, Tw11 0bp
Rear extension
Under consideration
–
PA26/2920
157a, Fairfax Road, Tw11 9bu
Garage conversion or garage
Under consideration
–
PA26/2470
88, Sandy Lane, Tw11 0df
Loft or dormer
Under consideration
–
PA26/2865
23, Cambridge Crescent, Tw11 8dx
Other householder work
Approved
Oct 2026
PA26/0871
5, Teddington Park, Tw11 8db
Rear extension
Approved
Sept 2026
PA26/2540
17, Victoria Road, Tw11 0bb
Side return or wrap-around
Under consideration
–
PA26/2634
79a, High Street, Tw11 8hg
Other householder work
Approved
Sept 2026
PA26/2722
81a, High Street, Tw11 8hg
Other householder work
Approved
Sept 2026
PA26/2723
10, Avenue Gardens, Tw11 0bh
Rear extension
Approved
Aug 2026
PA26/2502
18, Cambridge Crescent, Tw11 8dy
Other householder work
Under consideration
–
PA26/1980
20, Kingsmead Close, Tw11 9ep
Two-storey extension
Under consideration
–
PA26/2317
4, Vicarage Road, Tw11 8ez
Other householder work
Refused
Aug 2026
PA26/2237
157a, Fairfax Road, Tw11 9bu
Other householder work
Approved
Sept 2026
PA26/2086
57, Kingston Lane, Tw11 9hn
Garage conversion or garage
Approved
Sept 2026
PA26/2090
15, Walpole Crescent, Tw11 8ph
Side return or wrap-around
Approved
Jul 2026
PA26/2071
1, Trinder Mews, Tw11 8hy
Loft or dormer
Other
Aug 2026
PA26/1974
2, Kingston Lane, Tw11 9hw
Side extension
Approved
Jun 2026
PA26/1812
6, Birch Close, Tw11 8bj
Two-storey extension
Approved
Oct 2026
PA26/1823
34, Bolton Gardens, Tw11 9ay
Rear extension
Under consideration
–
PA26/1513
33, Cambridge Road, Tw11 8dt
Other householder work
Under consideration
–
PA26/1408
12, Bridgeman Road, Tw11 9ah
Side return or wrap-around
Under consideration
–
PA26/1235
45, Park Road, Tw11 0au
Rear extension
Under consideration
–
PA26/1182
34, Langham Road, Tw11 9hq
Rear extension
Under consideration
–
PA26/1186
16, Park Road, Tw11 0ag
Outbuilding or garden room
Under consideration
–
PA26/1144
54, Clarence Road, Tw11 0bw
Windows, doors or cladding
Approved
May 2026
PA26/1007
24, Gomer Gardens, Tw11 9at
Loft or dormer
Under consideration
–
PA26/1039
22, Gomer Gardens, Tw11 9at
Loft or dormer
Under consideration
–
PA26/1041
48, Clarence Road, Tw11 0bw
Other householder work
Approved
Apr 2026
PA26/0673
36, Bridgeman Road, Tw11 9ah
Rear extension
Other
Apr 2026
PA26/0750
The Coach House, Vicarage Road, Tw11 8ez
Loft or dormer
Under consideration
–
PA26/0703
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
29, Cedar Road, Tw11 9an
Loft or dormer
Approved
Mar 2026
PA26/0404
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.