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Greenwich · Loft conversion · Checked 30 Oct 2026

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

Short answer

Often not. A rear dormer adding no more than 40 m³ of roof volume on a terraced house, or 50 m³ on a semi-detached or detached house, set back from the eaves and below the ridge, is normally permitted development; front dormers, larger volumes and any loft to a flat need planning permission. In a conservation area roof extensions always need planning permission. Greenwich has conservation areas and Article 4 directions that remove some permitted development rights, so we check the address on Greenwich's constraints map before advising a route.

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Loft conversions in Greenwich depend on the house. Typical homes here: Georgian and early Victorian terraces and villas in West Greenwich, Blackheath and Greenwich town centre; Victorian terraces in Charlton, Plumstead, Westcombe Park and Woolwich. Designations to check first: Conservation areas; Article 4 directions; Thames flood risk. Applications are decided by Royal Borough of Greenwich and the Royal Greenwich Local Plan: Core Strategy with Detailed Policies (2014).

The permitted development rules for loft conversions

A loft conversion with a rear dormer is permitted development on a house if the added roof volume is no more than 40 m³ on a terraced house or 50 m³ on a semi-detached or detached house, the dormer sits at least 200 mm back from the eaves and no higher than the ridge, there is no dormer on the roof slope facing the road, materials are similar in appearance, and side windows are obscure-glazed.

Flats and maisonettes have no permitted development rights, so a loft to a top-floor flat always needs planning permission. Full-width box dormers that reach the ridge, and hip-to-gable conversions on semis whose volume exceeds 50 m³, also fall outside the allowance.

What changes in Greenwich

Roof extensions are not permitted development in a conservation area, so a dormer or hip-to-gable there needs a householder planning application designed to the area's appraisal.

The local constraints that most often decide the route in Greenwich are listed below, taken from our Greenwich area page. Each one is a reason to confirm the address on Greenwich's constraints map before relying on permitted development.

  • Conservation areas. Royal Greenwich has numerous conservation areas, including West Greenwich, Blackheath, Blackheath Park, Westcombe Park, Charlton Village, Eltham Palace, the Progress Estate and Woolwich Common. Source
  • Article 4 directions. Several conservation areas, notably the Progress Estate in Eltham and parts of Blackheath, have Article 4 directions removing permitted development for external alterations, so most changes need planning permission. Source
  • Thames flood risk. The riverside from Greenwich Peninsula through Charlton, Woolwich and Thamesmead lies in Flood Zones 2 and 3 behind the Thames Barrier and river defences. Source
  • Metropolitan Open Land and Royal Parks. Blackheath, Greenwich Park, Woolwich Common, Oxleas Wood and Shooters Hill are Metropolitan Open Land or Royal Park. Source
  • Listed buildings. Greenwich town centre, Blackheath and Eltham contain a high concentration of listed buildings. Source

What Greenwich planning officers look for

Common refusal reasons are rear extensions that breach the 45-degree line or exceed the neighbour's depth, roof extensions in conservation areas that break the roofline of a terrace, front dormers, and alterations to Span houses or the Progress Estate that depart from the original detailing. The council offers a paid pre-application service, which we recommend in the World Heritage Site buffer zone and Blackheath. Decisions often run past 8 weeks; allow 10–14 weeks.

Fees and timelines

Greenwich decides a householder application or a Lawful Development Certificate within 8 weeks of validation. The council fee is £528 for a householder application and £264 for a Lawful Development Certificate (England, from 1 April 2025; verify before applying).

Our own fee is fixed once quoted. The quote tool gives an indicative figure in minutes and a written quote follows within 24 hours.

Primary sources

02Questions

Loft conversions in Greenwich: common questions

How is the 40 m³ or 50 m³ measured?

It is the volume added beyond the original roof slope, including any earlier roof extensions, not the floor area of the new room. We calculate it on the drawings and include the calculation in the Lawful Development Certificate application.

Can I have a front dormer?

Not under permitted development: nothing may extend beyond the plane of the roof slope facing a highway. Front rooflights are fine. A front dormer needs planning permission and most councils refuse them unless the street already has them.

Do I need Building Regulations approval as well?

Yes, always. Permitted development and planning permission concern what you may build; Building Regulations govern how it is built, including the new floor structure, the stair, fire escape and insulation. We prepare that package after the planning route is confirmed.

How long does Greenwich take to decide?

The statutory period is 8 weeks from validation for both a householder application and a Lawful Development Certificate, and 42 days for a larger home extension prior approval. Decisions often run past 8 weeks; allow 10–14 weeks.

03Examples

Example projects that face these questions

Proposed loft floor plan for an L-shaped rear dormer loft conversion on a Victorian terrace in HackneyExample project
Loft conversionStoke Newington, Hackney

Loft Conversion in Stoke Newington, Hackney

L-shaped rear dormer loft conversion to a two-storey Victorian terrace, adding a double bedroom and en-suite within the 40 m³ permitted development allowance.

Typical route: Permitted development, proved with a Lawful Development Certificate

Proposed loft floor plan for a hip-to-gable and rear dormer conversion to an Edwardian semi in TwickenhamExample project
Loft conversionTwickenham, Richmond

Loft Conversion in Twickenham, Richmond upon Thames

Hip-to-gable roof extension with a rear dormer to an Edwardian semi-detached house in a Twickenham conservation area, creating a master bedroom and bathroom in the roof.

Typical route: Householder planning application in an Article 4 conservation area

Next step

Planning a loft conversion in Greenwich?

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