Rear extension drawings in Greenwich from £625
Blackheath, Charlton, Eltham and Woolwich: Royal Greenwich’s Urban Design Guide names 3.6 metres as the typical rear projection.
£625 £475 drawings + £150 survey (£625 total), no VAT to add
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The short answer
Greenwich’s Urban Design Guide SPD, adopted on 18 October 2023, says a 3.6 metre projection from the rear is typically considered appropriate, and that more can be considered where neighbours are not harmed. The roof should generally sit 300 millimetres below the first-floor window sill, ceilings should be 2.5 metres, and no part may oversail the boundary. Our fee is £475 drawings + £150 survey (£625 total), no VAT to add; the council’s fee is separate.
Rear extension drawings
from £625
- Drawings
- £475
- Measured survey
- £150
- Total you pay
- £625
- VAT
- None to add
- A measured survey of the back of the house, including any stepped rear walls and the first-floor sills
- A projection check against the 3.6 metre figure and the neighbours’ rear walls
- A roof height set 300 millimetres below the first-floor sill where the house allows it
- A check of your address against Greenwich’s Article 4 and conservation area controls
- Plans to the June 2025 validation list, and the route that fits submitted for you
£475 drawings + £150 survey (£625 total). A starting fee: we confirm one fixed figure after checking your address. The council’s own fee, where there is one, is paid to the council.
Get my fixed feeHow a Greenwich rear extension runs
Rear wall check
We find the original rear wall or walls, since each stepped wall can be extended on its own terms.
Survey
We measure the back, the sills above and the neighbours’ rear walls.
Design
You choose projection and roof, with the route and risk of each written down.
Draw and submit
We prepare the pack to the validation list and submit it, then answer the case officer.
What principle I.3.3 says
The Urban Design Guide replaced Greenwich’s older residential extensions guidance. Principle I.3.3 requires rear extensions to respond to the scale of the existing building and the size of the garden. A 3.6 metre projection from the rear is typically considered appropriate in Royal Greenwich; projections beyond that can be considered for certain house types where neighbourly amenity is not compromised, which the guide links to the borough’s dense nineteenth-century streets.
Where the original rear wall is stepped, each stepped wall counts as a rear wall of the original house, so the limits apply to each wall being extended as long as the stepped appearance is kept. For example, a Charlton terrace with an outrigger can be extended 3.6 metres from the outrigger and 3.6 metres from the main back wall, rather than measured from one line.
Roof, boundary and balcony rules
The guide says the roof of an extension should generally be 300 millimetres below the first-floor window sill, though it recognises this cannot always be achieved, and the floor-to-ceiling height should be at least 2.5 metres. A flat roof is generally preferred and a green or biodiversity roof helps reduce bulk. No part of an extension may exceed or oversail a boundary line, which is why parapet walls are common on party walls. The council generally does not support terraces or balconies above the flat roof of an extension.
Class A permitted development gives 3 or 4 metres, or 6 and 8 with prior approval, but the guide notes that rights have been removed for rear extensions in certain conservation areas. In Greenwich Article 4 areas, re-roofing and replacing windows and doors may also need permission. We check your road.
What Greenwich asks for, and CIL
The June 2025 validation list asks for a fire statement or a reasonable exception statement on householder applications, prefers drawings no larger than A3, returns plans marked “do not scale”, and suspends an invalid application for 28 days before withdrawing it.
Greenwich adopted its CIL charging schedule on 24 July 2024, in force from 26 July 2024, and asks for a CIL form from 100 square metres of net additional floor area, so a typical extension is outside it. Mayoral CIL is in band 3.
Rear extensions in Greenwich in numbers
469 of 495
Householder decisions by the Royal Borough of Greenwich between July 2025 and June 2026 (prior approvals left out) that were made inside 8 weeks.
Source: MHCLG live table PS2, district planning application statistics, July 2025 to June 2026 (GOV.UK)
3.6 m
Rear projection the Urban Design Guide says is typically considered appropriate in Royal Greenwich.
300 mm
Distance the roof of a single-storey rear extension should generally sit below the first-floor window sill.
2.5 m
Minimum floor-to-ceiling height the guide gives for a rear extension.
18 Oct 2023
Date Greenwich adopted the Urban Design Guide SPD.
3 m / 4 m
Deepest single-storey extension permitted development allows; 6 and 8 metres through prior approval.
Source: GPDO 2015, Schedule 2, Part 1, Class A: enlargement of a dwellinghouse (legislation.gov.uk)
Re-roofing
In Greenwich Article 4 areas, planning permission may be needed for replacing windows and doors and for re-roofing.
Source: Areas with extra planning restrictions, Article 4 directions (Royal Borough of Greenwich)
28 days
Time an invalid application is suspended before Greenwich withdraws it.
Source: Local Validation Requirements List, June 2025 (Royal Borough of Greenwich)
24 Jul 2024
Date Greenwich adopted its current CIL charging schedule, in force from 26 July 2024.
Source: Community Infrastructure Levy (Royal Borough of Greenwich)
£30.30
Mayoral CIL per square metre for permissions granted in 2026 in Greenwich, which is in band 3 (£25 when set in 2019). It applies only where CIL is due at all.
Source: Mayoral CIL: Annual CIL Rate Summary 2026 (London.gov.uk)
Questions about rear extensions in Greenwich
How deep can I go in Greenwich?
The council’s guide treats 3.6 metres as typical. More can be considered if neighbours are not harmed, and permitted development with prior approval can allow more.
My house has an outrigger. Where do I measure from?
From each original rear wall. The guide says stepped walls are each treated as a rear wall of the original house.
Can I have a roof terrace on the extension?
Generally not. The council does not support terraces or balconies above the flat roof of an extension.
Do I pay CIL on a kitchen extension?
Not normally. The council asks for a CIL form from 100 square metres of net additional floor area.
See how far your Greenwich house can go
Send the address and a photo of the back. We reply with the route and a fixed fee, from £475 drawings + £150 survey (£625 total).