What you could build at N9 8DY: 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 Ponders End South, Enfield.
52extensions seen within 600 m in the last 10 years
3loft conversions within 600 m in the last 10 years
90.6extensions 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.
Not in a conservation area (from council registers).
Article 4 direction (Borough wide): 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 Ponders End South.
Move to a home 20 m² bigger (about £559,000)
Stamp duty on the new home
£17,950
Estate agent on yours 1.2% + VAT
£6,480
Solicitors, buying and selling
£3,000
Survey
£600
Removals
£1,500
Money gone
£29,530
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
−£65,400
Money gone
−£7,900
On these figures, extending loses about £37,430 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.
20, St Alphege Road, N9 8bx
Rear extension
Refused
Sept 2026
26/03569/PRH
148, Nightingale Road, N9 8pt
Rear extension
Not needed / lawful
Sept 2026
26/03281/PRH
38, Nightingale Road, N9 8ar
Rear extension
Not needed / lawful
Aug 2026
26/03142/PRH
528, Hertford Road, N9 8ae
Rear extension
Not needed / lawful
Aug 2026
26/02950/PRH
164, Cuckoo Hall Lane, N9 8du
Rear extension
Not needed / lawful
Jul 2026
26/02530/PRH
2, Oaklands Avenue, N9 7lh
Loft or dormer
Approved
Jul 2026
26/02306/HOU
2, Cuckoo Hall Lane, N9 8dj
Rear extension
Withdrawn
Jun 2026
26/02228/PRH
61, Shirley Grove, N9 8es
Rear extension
Approved
Jul 2026
26/02180/PRH
48, Cambourne Avenue, N9 8qg
Rear extension
Not needed / lawful
Jun 2026
26/01891/PRH
17, Wellstead Avenue, N9 8qa
Side return or wrap-around
Refused
Jun 2026
26/01287/HOU
2, Cuckoo Hall Lane, N9 8dj
Rear extension
Approved
Jun 2026
26/01813/PRH
164, Cuckoo Hall Lane, N9 8du
Other householder work
Approved
Jun 2026
26/01666/HOU
447, Hertford Road, N9 7dh
Rear extension
Not needed / lawful
May 2026
26/01576/PRH
80, Nightingale Road, N9 8pu
Rear extension
Not needed / lawful
May 2026
26/01256/PRH
22, Rydal Way, En3 4pq
Rear extension
Approved
Apr 2026
26/00756/HOU
24, Shirley Grove, N9 8ep
Loft or dormer
Approved
Apr 2026
26/00052/HOU
20, St Alphege Road, N9 8bx
Rear extension
Not needed / lawful
Mar 2026
26/00413/PRH
287a, Galliard Road, N9 7ds
Garage conversion or garage
Refused
Jan 2026
25/03720/HOU
17, Wellstead Avenue, N9 8qa
Side return or wrap-around
Refused
Feb 2026
25/03602/HOU
80, Mottingham Road, N9 8ed
Loft or dormer
Approved
Jan 2026
25/03583/HOU
178, Nightingale Road, N9 8pt
Two-storey extension
Approved
Nov 2025
25/03169/HOU
105, Tudor Road, N9 8pa
Rear extension
Not needed / lawful
Oct 2025
25/03272/PRH
188, Galliard Road, N9 7dj
Rear extension
Not needed / lawful
Oct 2025
25/03247/PRH
178, Nightingale Road, N9 8pt
Rear extension
Not needed / lawful
Oct 2025
25/03168/PRH
17, Wellstead Avenue, N9 8qa
Rear extension
Approved
Oct 2025
25/02779/HOU
7, Scarborough Road, N9 8at
Rear extension
Not needed / lawful
Oct 2025
25/02850/PRH
20, Warren Close, N9 8qe
Porch or front extension
Approved
Aug 2025
25/02312/HOU
15, Byron Terrace, Hertford Road, N9 7dg
Rear extension
Not needed / lawful
Aug 2025
25/02277/PRH
20, Warren Close, N9 8qe
Rear extension
Approved
Jul 2025
25/01978/PRH
70, Cambourne Avenue, N9 8qg
Rear extension
Approved
Jul 2025
25/01881/PRH
129, Cuckoo Hall Lane, N9 8ds
Two-storey extension
Approved
Jun 2025
25/01521/HOU
66, Shirley Grove, N9 8ep
Rear extension
Approved
Jun 2025
25/01329/HOU
28, Rydal Way, En3 4pq
Rear extension
Not needed / lawful
May 2025
25/01339/PRH
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% (116)
88%
7 weeks
Basement
–
53% (17)
83%
8 weeks
Porch or front extension
–
88% (74)
81%
7 weeks
Share of decided applications approved since 2023 (number decided in brackets). Withdrawn applications aren't counted; many are withdrawn when refusal looks likely.