BOROUGH · PROJECT

Side return extension in Greenwich

Planning permission, real costs and what actually gets approved

Do you need planning permission for a side return extension in Greenwich?

Workable on the Victorian terraces of Greenwich, Charlton and the Lewisham-border streets; conservation designation decides permitted development versus a full application. Side extensions have no permitted-development route inside a conservation area.

Workable on the Victorian terraces of Greenwich, Charlton and the Lewisham-border streets; conservation designation decides PD versus a full application.

Where continuous terrace stock survives outside the tightest heritage cores, side returns are a familiar project judged on boundary wall height, neighbour daylight and roof junction detail. Near the historic town and World Heritage setting, design control is more exacting and listed building consent may apply as well as planning.

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What actually applies in Greenwich

Conservation areas in Greenwich

Real · planning.data.gov.uk

14 designated areas are recorded in the official dataset for this borough without published names. The area report still checks an address against their real boundaries — see the council's own conservation-area and Article 4 pages for the named schedules.

Source: planning.data.gov.uk · Open Government Licence · 14 recorded.

Article 4 directions in Greenwich

Real · planning.data.gov.uk

No Article 4 geometry for Greenwich appears in the national planning.data.gov.uk dataset, but the Royal Borough operates householder Article 4 directions in a number of its conservation areas — among them the Ashburnham Triangle, West Greenwich, East Greenwich, the Rectory Field, the Shrewsbury Park Estate and the Progress Estate — removing permitted development rights so that visible external alterations need planning permission. The Residential Extensions, Basements and Conversions Guidance SPD sets the design rules. Check the council's Article 4 pages for the position at a specific address.

Source: planning.data.gov.uk · Open Government Licence. Checked at address level by the area report.

Average house price
£459,985
Annual change
-2.6%

Prices: HM Land Registry UK House Price Index, December 2025 · Open Government Licence.

How often Greenwich grants householder applications: 77.6% of householder applications decided were granted (502 of 647) over 2025 Q2 to 2026 Q1 — rank 3 of 33 for lowest grant rate. London average: 85.6%. Householder applications are the class most side return extensions fall under. See the full householder approval-rate league table →
ROUTE

The planning route — PD or permission?

Under permitted development, side extensions (GPDO Class A) must be single storey, no more than 4m high and no wider than half the original house — but side extensions are excluded from PD entirely in conservation areas. Wrap-around schemes combining side and rear elements usually exceed PD limits and need full permission everywhere.

In practice, most London side returns proceed by full householder application. The good news is the precedent base: on streets of identical terraces, a consented side return three doors down is the strongest evidence your scheme can cite. Officers focus on the boundary wall height, neighbour daylight and the junction with the host roof.

LIMITS

Permitted development limits — side return extension

StoreysSingle storey only
Maximum height4m
Maximum widthNo wider than half the original house
Conservation areasSide extensions excluded from PD entirely
Wrap-around (side + rear combined)Usually exceeds PD — full permission

Limits summarise the General Permitted Development Order (Schedule 2, Part 1) as it applies in London. In Greenwich, a conservation area, Article 4 direction or listed status changes the route — the panels above show what is designated, and the address check confirms what applies at your property.

COST

How much does a side return extension cost in Greenwich?

Cost per m² (low)£3,200
Cost per m² (expected)£4,000
Cost per m² (high — wrap-around, conservation spec)£4,800+
Typical project (9–15m² incl. structural opening)£45,000 – £110,000
Professional fees, surveys, party wall (add)10–18% of build

Side returns price higher per m² than plain rear extensions because steelwork, underpinning the party wall and roof glazing are spread over fewer metres. Indicative ranges from real project data; VAT excluded.

TIME

Realistic timeline

Design and drawings4–8 weeks
Planning decision8–12 weeks (8-week statutory target)
Party wall award (boundary wall works)6–10 weeks (parallel)
Build3–4 months
WATCH

What catches people out in Greenwich

Party wall procedure on the shared flank is unavoidable. Do not design a contemporary wrap-around for listed stock without specialist heritage advice.

DISTRICTS

Postcode districts in Greenwich

FAQ

Side return extension in Greenwich, asked straight

01

Is a side return permitted development in Greenwich?

Only in limited cases outside conservation areas. Inside a conservation area, side extensions have no permitted-development route. Most genuine schemes proceed by full application.
02

How much does a side return cost?

Expect £3,200–£4,800+ per m² — typically £45,000–£110,000 for a 9–15m² infill including structural opening, before VAT and fees.
03

What do officers focus on?

Boundary wall height, daylight to the neighbour, roof junction detail and materials — with extra heritage scrutiny near the historic core.
04

Will I need a party wall agreement?

Almost certainly when building against or astride a shared boundary wall.
05

Does a neighbour's consent help?

Yes — matching consented depth on the same terrace is strong evidence for a full application.
CHECK

What applies at your address?

Borough-level rules only narrow it down. Enter a Greenwich postcode for the live constraint check — conservation area, Article 4 and sold-price comparables, cited to source.

Need it in writing for one address? A planning permission report for a Greenwich property — from £59, or surveyor-reviewed from £295.

Planning Permission Checker provides planning and cost intelligence for early feasibility only. It is not legal, planning, valuation, architectural, structural, or surveying advice. All estimates are indicative and must be verified by qualified professionals before purchase, design, planning submission, or construction.

Cost estimates are indicative only — not a quotation. Final price depends on survey, specification, structure, access, party wall matters, VAT, professional fees, and contractor availability.

Planning outcomes are not guaranteed. Local planning authorities make final decisions.

Check an address