What you could build at TW1 3LS: 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 Twickenham Town, Richmond upon Thames.
94extensions seen within 600 m in the last 10 years
11loft conversions within 600 m in the last 10 years
121.1extensions 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 (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 Twickenham Town.
Move to a home 20 m² bigger (about £883,000)
Stamp duty on the new home
£34,150
Estate agent on yours 1.2% + VAT
£10,224
Solicitors, buying and selling
£3,000
Survey
£600
Removals
£1,500
Money gone
£49,474
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
−£103,800
Money gone
−£46,300
On these figures, extending loses about £95,774 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.
137, Richmond Road, Tw1 3at
Outbuilding or garden room
Other
Oct 2026
PA26/2798
116, Amyand Park Road, Tw1 3hp
Basement
Other
Sept 2026
PA26/2825
23, Copthall Gardens, Tw1 4hh
Loft or dormer
Other
Sept 2026
PA26/2570
25, Lebanon Park, Tw1 3df
Loft or dormer
Approved
Sept 2026
PA26/1729
3, Strand House, The Embankment, Tw1 3du
Other householder work
Approved
Sept 2026
PA26/2468
54, Richmond Road, Tw1 3be
Other householder work
Approved
Sept 2026
PA26/2209
57, Hartington Road, Tw1 3el
Side extension
Under consideration
–
PA26/2580
2, Latham Close, Tw1 1bp
Loft or dormer
Approved
Sept 2026
PA26/2291
20, Church Street, Tw1 3nj
Other householder work
Refused
Aug 2026
PA26/2290
5, The Embankment, Tw1 3du
Windows, doors or cladding
Approved
Aug 2026
PA26/1981
10, Marble Hill Close, Tw1 3ay
Rear extension
Approved
Jul 2026
PA26/2177
3, Strafford Road, Tw1 3ad
Loft or dormer
Approved
Sept 2026
PA26/1479
36 40, Holly House, Heath Road, Tw1 4bz
Other householder work
Refused
Jul 2026
PA26/1747
19, Copthall Gardens, Tw1 4hh
Rear extension
Under consideration
–
PA26/1624
17, Canham House, 17 Heath Road, Tw1 4aw
Loft or dormer
Under consideration
–
PA26/1529
59, Sherland Road, Tw1 4hb
Side return or wrap-around
Under consideration
–
PA26/1376
57, Sherland Road, Tw1 4hb
Side return or wrap-around
Under consideration
–
PA26/1452
49, Copthall Gardens, Tw1 4hh
Rear extension
Under consideration
–
PA26/1061
Coniston, Riverside, Tw1 3dj
Loft or dormer
Under consideration
–
PA26/0869
28, Poulett Gardens, Tw1 4qr
Loft or dormer
Under consideration
–
PA26/0731
16, Cornwall Road, Tw1 3ls
Other householder work
Approved
Apr 2026
PA26/0650
46, Cole Park Road, Tw1 1hs
Loft or dormer
Approved
Apr 2026
PA26/0623
14, Station Yard, Tw1 4lj
Rear extension
Approved
Apr 2026
PA26/0511
8, Cole Park Road, Tw1 1hw
Windows, doors or cladding
Approved
Apr 2026
PA26/0451
185, Amyand Park Road, Tw1 3hn
Loft or dormer
Approved
Mar 2026
PA26/0464
Jacobs Ladder, Eel Pie Island, Tw1 3dy
Other householder work
Approved
Mar 2026
PA26/0179
13, Lancaster Place, Tw1 1hr
Loft or dormer
Approved
Apr 2026
PA26/0049
51, Copthall Gardens, Tw1 4hh
Rear extension
Approved
Mar 2026
PA25/4575
55, Lebanon Park, Tw1 3dh
Garage conversion or garage
Approved
Mar 2026
PA25/4554
13, Bell Lane, Tw1 3nu
Loft or dormer
Approved
Feb 2026
PA25/3920
4, Marble Hill Gardens, Tw1 3ax
Rear extension
Approved
Dec 2025
PA25/3148
26, Amyand Park Road, Tw1 3he
Loft or dormer
Approved
Jan 2026
PA25/4140
23 - 25, King Street, Tw1 3sd
Other householder work
Approved
Dec 2025
PA25/4153
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
80% (5)
–
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.