BOROUGH · PROJECT

Garden room in Greenwich

Planning permission, real costs and what actually gets approved

Do you need planning permission for a garden room in Greenwich?

Generous gardens in Eltham, Charlton and Blackheath often suit Class E garden rooms under permitted development when height, coverage and incidental-use limits are met. Conservation-area designation and listed curtilage are the constraints. Keep the use incidental.

Generous gardens in Eltham, Charlton and Blackheath suit garden rooms under PD; conservation-area designation and height and incidental-use limits are the constraints.

Deeper suburban plots clear the 50% coverage rule more easily than short yards, provided the 2.5m boundary-height limit is respected. Near heritage cores, design sensitivity rises even when Class E still applies at the rear. Flats never had outbuilding rights.

CHECK

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 garden rooms fall under. See the full householder approval-rate league table →
ROUTE

The planning route — PD or permission?

Permitted development (GPDO Class E) allows outbuildings for purposes incidental to the house: maximum 2.5m height within 2m of a boundary (4m for dual-pitched roofs further in), no more than half the garden covered, nothing forward of the principal elevation, and no sleeping accommodation. Within conservation areas Class E still applies at the rear, but outbuildings at the side are excluded.

The 'incidental use' test matters: an office or gym qualifies; a self-contained annexe or rentable unit does not and needs full permission. Listed buildings lose Class E entirely — any outbuilding in the curtilage of a listed house needs an application. Where you intend to run a business with visitors or convert to sleeping space later, take the planning route up front.

LIMITS

Permitted development limits — garden room

Maximum height within 2m of a boundary2.5m
Maximum height further from a boundary4m for a dual-pitched roof
Garden coverage (all outbuildings and extensions together)No more than half the garden
PositionNothing forward of the principal elevation
UseIncidental to the house — no sleeping accommodation
Conservation areasRear only — outbuildings at the side excluded
Listed buildingsClass E lost entirely — application required

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 garden room cost in Greenwich?

Cost per m² (low — prefabricated)£2,200
Cost per m² (expected — insulated, serviced)£3,000
Cost per m² (high — architect-designed, plumbed)£3,800+
Typical project (9–16m²)£25,000 – £60,000
Groundworks, power run, network (often quoted separately)£3,000 – £12,000

The honest budget includes the invisible half: foundations, armoured power run, data, and drainage if plumbed. Ranges from real project data; VAT excluded.

TIME

Realistic timeline

Design / specification2–6 weeks
Lawful Development Certificate (optional, recommended)4–8 weeks
Full application (listed curtilage, non-incidental use)8–12 weeks (8-week statutory target)
Groundworks and build2–8 weeks
WATCH

What catches people out in Greenwich

Roof height within 2m of a boundary and cumulative garden coverage are the usual Class E failures. Listed curtilage removes the route entirely.

DISTRICTS

Postcode districts in Greenwich

FAQ

Garden room in Greenwich, asked straight

01

Do I need planning permission for a garden room in Greenwich?

Often not for a rear incidental outbuilding within Class E limits on a house. Conservation areas, listed curtilage, flats and sleeping use need careful checking.
02

How much does a garden room cost?

£25,000–£60,000 for most insulated, powered 9–16m² rooms, plus £3,000–£12,000 for groundworks and services.
03

Do larger gardens help?

They help with the 50% coverage rule, but height limits and incidental use still apply.
04

Can I sleep in it?

Not under permitted development.
05

Should I get a Lawful Development Certificate?

Yes on permitted-development schemes — useful when you sell.
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