BOROUGH · PROJECT

Loft conversion in Greenwich

Planning permission, real costs and what actually gets approved

Do you need planning permission for a loft conversion in Greenwich?

Routine on the terraces and semis of Charlton, Eltham and Plumstead under permitted development outside conservation areas. Inside a conservation area, dormers are scrutinised through a full application. Building regulations always apply.

Routine on the terraces and semis of Charlton, Eltham and Plumstead under PD; the conservation areas scrutinise dormers.

Rear dormers are a standard space-adder on unconstrained stock. In conservation areas and Article 4 streets, rear-facing, well set-back dormers have a better record than box forms or front alterations. Listed roofs in the historic core may need listed building consent as well as planning.

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 loft conversions fall under. See the full householder approval-rate league table →
ROUTE

The planning route — PD or permission?

Permitted development (GPDO Class B) allows roof enlargements up to 40m³ on terraced houses and 50m³ on semis and detached — enough for a substantial rear dormer — provided nothing projects beyond the roof plane of the principal elevation, materials are similar, and dormers sit back from the eaves. Class B is excluded in conservation areas.

In conservation areas the route is a full application, and roof form decides it: rear mansards with traditional slate and proportioned dormers have a strong record on Victorian terraces; box dormers and front-facing alterations are the classic refusals. Article 4 directions (Muswell Hill is the local example) pull roof works into planning control even where conservation policy alone might not.

Whatever the route, building regulations approval is always required — fire escape, stair geometry and floor structure — and a Lawful Development Certificate is cheap insurance on PD schemes.

LIMITS

Permitted development limits — loft conversion

Roof volume added — terraced houseUp to 40m³
Roof volume added — semi-detached or detachedUp to 50m³
Principal (street-facing) roof planeNo extension beyond it
DormersSet back from the eaves; materials similar
Conservation areasClass B excluded — full permission
FlatsAlways need permission
Building regulationsAlways required, whatever the planning route

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 loft conversion cost in Greenwich?

Cost per m² (low — rooflight conversion)£3,000
Cost per m² (expected — rear dormer)£3,700
Cost per m² (high — mansard, conservation spec)£4,500+
Typical project (20–28m² with bathroom)£86,000 – £180,000
Professional fees, surveys, party wall (add)8–15% of build

Mansards in conservation areas sit at the top of the range — natural slate, lead detailing and officer negotiation all cost. Ranges calibrated from real project data; VAT excluded.

TIME

Realistic timeline

Design and drawings4–6 weeks
PD route (Lawful Development Certificate)4–8 weeks
Full application (conservation areas)8–12 weeks (8-week statutory target)
Party wall award4–8 weeks (parallel)
Build10–14 weeks
WATCH

What catches people out in Greenwich

Headroom and stair position still filter schemes early. Front-facing and oversized box dormers are classic refusals on protected streets.

DISTRICTS

Postcode districts in Greenwich

FAQ

Loft conversion in Greenwich, asked straight

01

Do I need planning permission for a loft conversion in Greenwich?

Outside conservation areas, many house rear-dormer lofts proceed under permitted development within volume limits. Inside a conservation area, or on listed buildings, expect a full application and any required listed building consent.
02

How much does a loft conversion cost?

Budget £3,000–£4,500+ per m², or £86,000–£180,000 for a typical 20–28m² conversion with a bathroom, before VAT and fees.
03

What designs get approved in conservation areas?

Rear-facing dormers that leave the street-facing roof plane alone. Box dormers and front alterations are classic refusals.
04

Is building regulations approval required?

Always — fire escape, stair geometry and floor structure are controlled either way.
05

Can I convert a loft in the historic core?

Only with the right consents — listed building consent is often required as well as planning where listing applies. Confirm before design.
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