What you could build at DA7 5RB: 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 Bostall, Bexley.
82extensions seen within 600 m in the last 10 years
4loft conversions within 600 m in the last 10 years
90extensions 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 Bostall.
Move to a home 20 m² bigger (about £639,000)
Stamp duty on the new home
£21,950
Estate agent on yours 1.2% + VAT
£7,560
Solicitors, buying and selling
£3,000
Survey
£600
Removals
£1,500
Money gone
£34,610
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
−£68,400
Money gone
−£10,900
On these figures, extending loses about £45,510 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.
72, Pembury Road, Da7 5ln
Rear extension
Not needed / lawful
Aug 2026
26/00987/GPDE
12, Westbourne Road, Da7 5lg
Loft or dormer
Refused
Jun 2026
26/00831/LDCP
28, First Avenue, Da7 5sx
Side return or wrap-around
Approved
Jun 2026
26/00803/FUL
59, Abbotts Walk, Da7 5rl
Loft or dormer
Approved
Jun 2026
26/00690/FUL
38, Ashbourne Avenue, Da7 5ns
Loft or dormer
Approved
Jun 2026
26/00683/FUL
141, King Harolds Way, Da7 5rb
Rear extension
Under consideration
–
26/00452/GPDE
41, Madison Crescent, Da7 5sy
Two-storey extension
Approved
May 2026
26/00579/FUL
45, Malvern Avenue, Da7 5le
Loft or dormer
Approved
Apr 2026
26/00405/LDCP
Wilkinson House, Powys Close, Da7 5rs
Other householder work
Approved
May 2026
26/00334/PRIOR
154, Okehampton Crescent, Da16 1db
Garage conversion or garage
Approved
Apr 2026
26/00305/FUL
131, Brixham Road, Da16 1el
Outbuilding or garden room
Approved
Apr 2026
26/00231/LDCP
186, Brampton Road, Da7 4sy
Rear extension
Approved
Mar 2026
26/00272/GPDE
12a, King Harolds Way, Da7 5qu
Side extension
Approved
Jun 2026
26/00130/LDCP
27, Abbotts Walk, Da7 5rl
Rear extension
Not needed / lawful
Mar 2026
26/00149/GPDE
28, Barry Avenue, Da7 5ll
Loft or dormer
Approved
Feb 2026
25/02613/LDCP
28, Barry Avenue, Da7 5ll
Rear extension
Refused
Feb 2026
25/02614/GPDE
12a, King Harolds Way, Da7 5qu
Side extension
Refused
Jan 2026
25/02438/LDCP
43, First Avenue, Da7 5ss
Loft or dormer
Approved
Dec 2025
25/02193/LDCP
43, First Avenue, Da7 5ss
Rear extension
Not needed / lawful
Dec 2025
25/02194/GPDE
72, King Harolds Way, Da7 5qz
Loft or dormer
Approved
Dec 2025
25/02071/LDCP
29, Barry Avenue, Da7 5lj
Loft or dormer
Approved
Nov 2025
25/01993/LDCP
29, Barry Avenue, Da7 5lj
Rear extension
Not needed / lawful
Nov 2025
25/01994/GPDE
17, Abbotts Walk, Da7 5rl
Loft or dormer
Approved
Nov 2025
25/01925/LDCP
45, Abbotts Walk, Da7 5rl
Rear extension
Not needed / lawful
Oct 2025
25/01768/GPDE
24, Abbotts Walk, Da7 5rj
Rear extension
Not needed / lawful
Oct 2025
25/01893/GPDE
24, Abbotts Walk, Da7 5rj
Loft or dormer
Approved
Nov 2025
25/01853/LDCP
22, Longleigh Lane, Da7 5sr
Loft or dormer
Approved
Nov 2025
25/01884/LDCP
131, Brixham Road, Da16 1el
Loft or dormer
Approved
Nov 2025
25/01864/LDCP
47, Malvern Avenue, Da7 5le
Side extension
Approved
Nov 2025
25/01854/LDCE
47, Malvern Avenue, Da7 5le
Side extension
Under consideration
–
25/01854/LDCP
131, Brixham Road, Da16 1el
Two-storey extension
Approved
Oct 2025
25/01778/FUL
69, West Heath Road, Se2 0ru
Two-storey extension
Approved
Oct 2025
25/01766/FUL
6, Powys Close, Da7 5rp
Two-storey extension
Approved
Oct 2025
25/01639/FUL
35, Ashbourne Avenue, Da7 5nt
Side extension
Approved
Sept 2025
25/01609/FUL
23, Oakhurst Avenue, Da7 5jl
Rear extension
Approved
Sept 2025
25/01545/FUL
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.
100% (7)
81% (67)
88%
8 weeks
Basement
–
–
83%
9 weeks
Porch or front extension
–
81% (16)
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.