Redbridge, London
L-shaped dormer drawings in Redbridge
An L-shaped dormer on a Redbridge house turns a cramped roof into two rooms and a landing, and the drawings have to satisfy the Redbridge Local Plan 2015-2030 and the Housing Design Guide SPD before a builder can price it. We draw them as MCIAT chartered architectural technologists, for a fixed quote after a free constraints check, VAT included.
Fixed quote after a free constraints check
- MCIAT chartered
- £2m PI insured
- LABC Partnered
- Fixed fees, VAT included
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How we work on l-shaped dormer drawings
Nine steps from first call to approval.
Enquiry and constraints check
We check the property against conservation areas, listed status, Article 4 directions, tree preservation orders, flood zone and planning history. We choose the right route and send a fixed quote.
Measured survey
We survey the house on one datum: rooms, levels, boundaries, drains, trees and the neighbours' windows that the 45° and 25° tests depend on.
Design options
We model the house in Revit and show you options in 3D and plan, with the planning strategy and the precedents in your street.
Design frozen
You choose an option in writing. Nothing changes after this without your say.
Independent check
A second chartered technologist checks every sheet against the council's validation checklist and the policy. A senior review signs it off before anything is submitted.
Submission
We prepare the forms, certificates, fee and documents and submit through the Planning Portal.
Officer liaison
We answer the planning officer and make any amendments within five working days, at no charge until approval.
Building regulations
Technical drawings are coordinated with the structural engineer's calculations, the drainage and the planning conditions.
Approval and hand-over
Building control approval, then a next-steps pack covering the commencement notice, party wall timing and CIL.
Free redraws until approval. Every drawing set is checked independently, and the checker is never the person who drew it.
Request a fixed quote
How Redbridge policy shapes an L-shaped dormer
Redbridge adopted its local plan in 2,018, and the document that officers reach for on roof alterations is the Housing Design Guide SPD. A dormer that wraps around an outrigger is read against both. The questions are simple to state: does the new volume dominate the original roof, and does it look like part of the house or a box dropped on top?
In Ilford and Wanstead the typical candidate is a Victorian or Edwardian terrace with a rear addition. Further out, around Hainault and Chadwell Heath, the interwar semi is more common, and its roof often has a hipped side that changes the geometry of the L. We survey the house first and draw the roof as it stands, because the right answer for a terrace is rarely right for a semi.
Permitted development is the quickest route when it is open. The national limit on the new roof is 40 m³ (terrace house) / 50 m³ (any other house) additional roof volume, and an L over a deep outrigger can use most of that on its own. We calculate the volume on the model, then tell you whether to reduce the scheme or apply for permission.
Local figures for Redbridge
| Measure | Value | Period | Source |
|---|---|---|---|
| Householder decisions | 991 decisions | 1 July 2025 - 30 June 2026 | assets.publishing.service.gov.uk |
| Householder applications granted | 82.8 % | 1 July 2025 - 30 June 2026 | assets.publishing.service.gov.uk |
| Householder applications decided in time | 94.7 % decided within 8 weeks or an agreed extended period | 1 July 2025 - 30 June 2026 | assets.publishing.service.gov.uk |
| Conservation areas | 16 named conservation areas published by the council | — | planning.data.gov.uk |
| Listed building entries | 134 list entries (Historic England, within the LPA boundary) | — | planning.data.gov.uk |
| Green Belt share of the council area | 34 % of council area covered by green-belt polygons | — | planning.data.gov.uk |
| Mayoral CIL rate (indexed) | 72.73 £/m² (indexed, permissions granted in 2026) | — | london.gov.uk |
| GPDO 2015 Sch 2 Pt 1 Class B, para B.1(d) | 40 m³ (terrace house) / 50 m³ (any other house) additional roof volume | — | legislation.gov.uk |
| Class B, condition B.2(b)(i)-(ii) | Eaves-retention and 0.2 m set-back do not apply where the enlargement joins the original roof to the roof of a rear or side extension | — | legislation.gov.uk |
| Class B, para B.1(f) | Class B roof enlargements are not permitted development on article 2(3) land | — | legislation.gov.uk |
A blank value means the figure has not been published, not that there are none. Check your own address with the council.
Householder applications by street in Redbridge
| Street | Applications | Approved |
|---|---|---|
| Wensleydale Avenue | 37 | 73% |
| Kings Avenue | 33 | 71% |
| Gyllyngdune Gardens | 32 | 39% |
| Malford Grove | 31 | 71% |
| Wanstead Park Avenue | 29 | 89% |
| Broadwalk | 27 | 91% |
| Falmouth Gardens | 27 | 88% |
| Levett Gardens | 27 | 58% |
| Beehive Lane | 25 | 48% |
| Goodmayes Lane | 24 | 71% |
| High View Road | 24 | 83% |
| Woodlands Avenue | 24 | 86% |
| Beattyville Gardens | 23 | 78% |
| Bressey Grove | 23 | 86% |
| Monkhams Avenue | 23 | 86% |
Loft enlargement in section: the permitted development limits
A dormer on the rear slope, with the limits that decide whether it needs planning permission.
- A · Extra roof volume allowed
- 40 m³ (terrace house) / 50 m³ (any other house) additional roof volume
- B · Set-back from the eaves
- Original eaves maintained; enlargement set at least 0.2 m from the eaves measured up the roof slope, so far as practicable (not required for hip-to-gable or roofs joining a rear/side extension)
- C · Height limit
- No part higher than the highest part of the existing roof
Redbridge figures that matter for a dormer
The council decided 991 householder applications in the latest published year and granted 82.8 per cent. Of those, 94.7 per cent were decided within eight weeks or an agreed extension. A planning route for a dormer is therefore a realistic plan, though these are borough-wide records and say nothing certain about one address.
Constraints are the other half. The council publishes 16 conservation areas, and Historic England lists 134 buildings within the borough boundary. Inside a conservation area the national position is: Class B roof enlargements are not permitted development on article 2(3) land. A dormer there always needs an application.
Roughly a third of Redbridge is green belt: the figure is 34 per cent of the borough. Roof extensions add no footprint, so the green-belt size test matters less for a dormer than for a rear extension, but we still check the boundary so nothing surprises you later.
Where the L meets the outrigger
The detail that decides whether an L-shaped dormer looks right is the junction. The general rule on set-backs is relaxed here: Eaves-retention and 0.2 m set-back do not apply where the enlargement joins the original roof to the roof of a rear or side extension. That lets the dormer run flush across the roofs without a stepped edge.
Redbridge terraces often have an outrigger with a shallow lean-to roof, and its eaves height sets the floor level of the new back room. We draw a section through the junction showing the steel, the insulation build-up and the gutter line, so the builder is not guessing at the valley.
Height is capped by the existing roof: No part higher than the highest part of the existing roof. The proposed elevation shows the dormer ridge below the original, which also helps the officer see that the scheme is subordinate.
Neighbours, stairs and fire on a Redbridge job
Most Redbridge terraces and semis share a roof structure with next door, so a party wall notice is normal. The rule is: Party structure notice at least 2 months before work. Get the notice out early and the programme holds. Our party wall notices service prepares it alongside the drawings.
The stair is the next squeeze. Where full headroom cannot be reached the regulations allow: Loft conversions where 2.0 m cannot be achieved: 1.9 m at the centre of the stair, 1.8 m at the side (half width). We test the stair position in section before the layout is fixed, because moving a stair late is expensive.
Once the loft is a second upper storey, fire protection follows. For the new storey the guidance asks: New storey above 4.5 m by loft conversion: protect the full escape route with fire-resisting doors (min E 20) and partitions (min REI 30). Those details go into your building regulations drawings.
Cost, levy and what you receive
There is no list price for an L-shaped dormer, because the roof and the junction vary so much from house to house. You get a fixed quote once we have checked the address, with VAT included, and if the council asks for changes we redraw at no charge until approval.
A dormer adds floor area, and floor area can attract the Mayoral levy. Redbridge sits in band 2, at £72.73 per square metre this year. We confirm whether a charge applies to your design in the next-steps pack.
You receive existing and proposed plans, elevations, a roof plan and sections, all from one Revit model, and we show you the design options in 3D before the drawings are finished. A second chartered technologist checks every sheet before it is issued.
Related drawings and neighbouring boroughs
If the L is more than your house needs, compare a plain dormer loft conversion in Redbridge, or look at the wider loft conversion drawings in Redbridge. A rear extension below can share the same set: see rear extension drawings in Redbridge.
Our overview of architectural drawings in Redbridge covers the borough as a whole. Across the border we also draw L-shaped dormers in Waltham Forest, in Newham and in Barking and Dagenham, and the service guide is L-shaped dormer drawings.
What you receive
Related pages
Other services in Redbridge
Questions
Can I build an L-shaped dormer in Redbridge without planning permission?
Sometimes. The roof volume limit is 40 m³ (terrace house) / 50 m³ (any other house) additional roof volume, and it does not apply in a conservation area: Class B roof enlargements are not permitted development on article 2(3) land. We check your address first.
How many householder applications does Redbridge grant?
In the latest figures the council granted 82.8 per cent of 991 householder decisions. That is a borough average, not a prediction for your house.
Does an L-shaped dormer need a party wall notice?
On a terrace or semi, usually. Party structure notice at least 2 months before work.
Do the usual set-back rules apply where the dormer joins the outrigger?
Eaves-retention and 0.2 m set-back do not apply where the enlargement joins the original roof to the roof of a rear or side extension.
Sources and dates
- assets.publishing.service.gov.uk, retrieved
- planning.data.gov.uk, retrieved
- planning.data.gov.uk, retrieved
- planning.data.gov.uk, retrieved
- london.gov.uk, retrieved
- legislation.gov.uk, retrieved
- redbridge.gov.uk, retrieved
- redbridge.gov.uk, retrieved
- legislation.gov.uk, retrieved
- gov.uk, retrieved
- gov.uk, retrieved
- london.gov.uk, retrieved
- Contains public sector information licensed under the Open Government Licence v3.0.
- Contains OS data © Crown copyright and database right 2026.
- Contains HM Land Registry data © Crown copyright and database right 2026. This data is licensed under the Open Government Licence v3.0.
- Contains Historic England data © Historic England 2026. Contains Ordnance Survey data © Crown copyright and database right 2026.
Tell us about your property.
We check the constraints, then send a fixed fee. Messages before 3pm get a reply the same working day.