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Improving at N20 8AN

What you could build at N20 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 Totteridge & Barnet Gate, Barnet.

9extensions seen within 600 m in the last 10 years

0loft conversions within 600 m in the last 10 years

78%of 40 householder applications nearby approved (since 2023)

123extensions 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 Totteridge conservation area: permitted development is narrower (for example no side extensions or roof cladding), and demolition and works to trees need consent.
Article 4 direction (Article 4 Small Houses in Multiple Occupation (HMO) Area 1): 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.

What neighbours have built

Home	Work	Seen	Space added	Floor area	Rooms	Distance
20, Oaklands Road	Extension	2026	+52 m²	226 m² → 278 m²	–	321 m
21, Harmsworth Way	Extension	2025	+90 m²	280 m² → 370 m²	11 → 10	395 m
47, Pine Grove	Extension	2024	+128 m²	253 m² → 381 m²	–	359 m
Woodlands, Pine Grove	Extension	2024	+404 m²	594 m² → 998 m²	–	362 m
17, Totteridge Village	Extension	2022	+82 m²	322 m² → 404 m²	5 → 9	367 m
Spindlewood, 62, Totteridge Village	Extension	2020	+89 m²	181 m² → 270 m²	6 → 7	277 m

Planning applications nearby

Address	Work	Outcome	Decided	Drawings and agent
19, Priory Close, N20 8bb	Side return or wrap-around	Under consideration	–	26/3537/HSE
28, Revelstroke, Totteridge Village, N20 8jn	Windows, doors or cladding	Under consideration	–	26/3422/HSE
18, Priory Close, N20 8bb	Other householder work	Under consideration	–	26/3059/HSE
Birchwood, Barnet Lane, N20 8ap	Outbuilding or garden room	Under consideration	–	26/2986/HSE
15, Totteridge Village, N20 8pn	Other householder work	Refused	Sept 2026	26/2682/HSE
25, Wildwood, Totteridge Village, N20 8pn	Side return or wrap-around	Approved	Sept 2026	26/2603/HSE

How often householder applications are approved

Work	Totteridge & Barnet Gate	Barnet	London	Typical decision time
All householder applications	74% (307)	76% (5649)	80%	8 weeks
Loft or dormer	82% (131)	81% (1882)	81%	8 weeks
Rear extension	69% (52)	66% (1643)	79%	8 weeks
Two-storey extension	67% (36)	74% (662)	72%	8 weeks
Other householder work	60% (30)	65% (389)	70%	8 weeks
Side return or wrap-around	–	85% (148)	88%	8 weeks
Windows, doors or cladding	75% (12)	95% (317)	90%	8 weeks
Outbuilding or garden room	60% (15)	81% (108)	79%	8 weeks
Side extension	100% (6)	94% (120)	86%	8 weeks

Cost and the value it adds

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 Totteridge & Barnet Gate.

Your home is worthExtra space you need (m²)Homes here sell for, per m²Building cost per m²Share of that an extension adds (%)

Move to a home 20 m² bigger (about £1,270,000)

Stamp duty on the new home	£70,750
Estate agent on yours 1.2% + VAT	£16,056
Solicitors, buying and selling	£3,000
Survey	£600
Removals	£1,500
Money gone	£91,906

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	−£93,000
Money gone	−£35,500

On these figures, extending loses about £127,406 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.

Find help: RIBA Find an Architect ↗ · CIAT architectural technologists ↗ · TrustMark tradespeople ↗ · Federation of Master Builders ↗ · Planning Portal guides ↗

General guidance, not planning or legal advice. Fees and rules as checked in October 2026; confirm with the council.

Energy certificates: MHCLG (OGL). Planning applications: GLA Planning London Datahub. Conservation areas and Article 4: planning.data.gov.uk (OGL).

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Improving at N20 8AN

The rules at this address

What neighbours have built

Planning applications nearby

How often householder applications are approved

Cost and the value it adds

Move or improve?

Getting started

Go deeper

Improving at N20 8AN

N20 8AN is on The Pastures

The rules at this address

What neighbours have built

Planning applications nearby

How often householder applications are approved

Cost and the value it adds

Move or improve?

Getting started

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N20 8AN is on The Pastures