Double-storey extension drawings in Redbridge from £905
Ilford, Wanstead, Woodford and Barkingside: upstairs gets 3 metres and half the house width at most, while downstairs follows the single-storey depths.
£905 £755 drawings + £150 survey (£905 total), no VAT to add
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The short answer
Redbridge’s Housing Design SPD, adopted in September 2019, treats the ground floor of a two-storey extension by the single-storey depths, 3.5 metres on a terrace or semi and 4.5 on a detached house. The first-floor part should generally be no deeper than 3 metres and no more than half the width of the original rear elevation, inside the 45 degree rule, with eaves no higher than the house’s. Our fee is £755 drawings + £150 survey (£905 total), no VAT to add; the council’s fee is separate.
Double-storey extension drawings
from £905
- Drawings
- £755
- Measured survey
- £150
- Total you pay
- £905
- VAT
- None to add
- A measured survey of both floors at the back and the nearest habitable windows next door, ground and first floor
- The 45 degree rule drawn in plan and in elevation, as the SPD describes it
- A first-floor block sized to half the original rear elevation and 3 metres deep
- A roof that matches the original and eaves no higher than the house’s own
- Plans to the April 2024 validation list, and the route that fits submitted for you
£755 drawings + £150 survey (£905 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 Redbridge double-storey extension runs
Rule check
We set the 3 metre and half-width limits and the 45 degree lines against your neighbours.
Survey
We measure both floors, the eaves and the neighbours’ nearest windows.
Design
You choose what goes upstairs and where, with the route written down.
Draw and submit
We prepare the pack to the validation list and submit it.
Ground floor longer, first floor shorter
Section 3.3 of the SPD says the ground-floor part of a two-storey extension follows the same depth principles as a single-storey one. The first-floor element should generally be kept to a maximum of 3 metres and must also have regard to the 45 degree rule. It should generally be no more than half the width of the original rear elevation, so it stays proportionate and subordinate. Its eaves should not be higher than the eaves of the house, and the roof should match the original roof design.
For example, an Ilford semi with a 3.5 metre kitchen can add a first-floor bedroom 3 metres deep over half the back wall. Wrap-around extensions around an older rear projection need low eaves, kept to 2.4 metres above ground.
The 45 degree rule in plan and elevation
The SPD explains the rule in two views. In plan, lines are drawn at 45 degrees from the centre of the nearest habitable-room window, ground or first floor, of the adjoining property and the footprint of the first-floor extension should fit inside that area. In elevation, lines are drawn upwards from the centre of the nearest ground-floor habitable window and the elevation of the extension should fit inside as well.
Permitted development allows more than one storey only up to 3 metres and not within 7 metres of the rear boundary, so most of these are householder applications. Redbridge has 16 conservation areas, including the Aldersbrook and Lake House Article 4 direction of 28 October 2020, and we check your address first.
Validation and CIL
Redbridge’s April 2024 validation list asks for a roof plan on all but change-of-use applications, a fire statement where a roof is changed, and a design and access statement from 100 square metres of new floor space in a conservation area.
Redbridge CIL is £125.56 a square metre for permissions granted in 2026, on 100 square metres or more of new floor space, so most double-storey extensions on a house are outside it. Mayoral CIL is in band 2.
Double-storey extensions in Redbridge in numbers
680 of 706
Householder decisions by Redbridge Council 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 m
Depth the first-floor part of a two-storey rear extension should generally not exceed.
Half width
The first-floor part should generally be no more than half the width of the original rear elevation.
45°
Lines drawn from the centre of the nearest habitable window next door, in plan and in elevation, within which the extension should fit.
Host eaves
The eaves of the extension should not be higher than the eaves of the host property.
Sep 2019
Date Redbridge adopted its Housing Design SPD.
16
Conservation areas in Redbridge, according to the council’s own page.
April 2024
Date of Redbridge’s current Local and National Planning Application Requirement List.
£125.56
Redbridge CIL per square metre for permissions granted in 2026: a flat £70 with indexation.
£72.73
Mayoral CIL per square metre for permissions granted in 2026 in Redbridge, which is in band 2 (£60 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 double-storey extensions in Redbridge
How deep can the first floor be?
Generally no more than 3 metres, inside the 45 degree rule, and no more than half the width of the original rear elevation.
Can the kitchen below go further?
Yes, to the single-storey depths: 3.5 metres on a terrace or semi, 4.5 on a detached house, and no further than the neighbours.
Must the roof match?
The roof should match the original house’s roof design, and the extension’s eaves should not be higher than the original.
Do I pay CIL on a double-storey extension?
Not normally. CIL arises from 100 square metres of new floor space or a new dwelling.
See what your Redbridge house can take upstairs
Send the address and a photo of the back. We reply with the route and a fixed fee, from £755 drawings + £150 survey (£905 total).