Rear Dormer Loft Conversions · SE20 Anerley
Fixed-fee rear dormer drawings for Penge, Anerley, Crystal Palace Park fringe in the SE20 postcode, drawn by an MCIAT-chartered architectural technologist and submitted to Bromley Council. Bromley controls SE20's conservation areas around Penge; SE20 is one of south-east London's most affordable period markets.
MCIAT chartered drawings for planning, building regs, lofts and extensions — fixed fees 30% below typical London architects. Tell us what you need and we’ll reply the same working day.
A rear dormer is the workhorse loft conversion on SE20's terraces in Anerley — a box across the rear roof slope adding a double bedroom and bathroom while keeping the front roofline intact for the street. Most rear dormers near Penge, Anerley, Crystal Palace Park fringe are Permitted Development, which we confirm with Bromley Council via a Lawful Development Certificate.
London's most popular loft type — the full-width rear dormer. Planning or Permitted Development route assessed for your Anerley property, building regulations, structural steelwork and Party Wall notices, all fixed fee.
Across Penge, Anerley, Crystal Palace Park fringe in SE20, the dominant property is victorian and edwardian terraces and villas around penge and anerley, with mansion blocks and post-war pockets near the crystal palace park. That stock shapes what rear dormer drawings looks like here: the right approach for a period terrace differs from a mansion-block flat or a new-build, and Bromley Council judges each on design quality and neighbour impact. We survey the specific Anerley property, confirm the planning route — Permitted Development, a Lawful Development Certificate, or full planning — and draw a council-ready set tailored to the SE20 streetscape.
Housing stock in SE20: Victorian and Edwardian terraces and villas around Penge and Anerley, with mansion blocks and post-war pockets near the Crystal Palace park.
Within the district: Penge, Anerley, Crystal Palace Park fringe.
Streets we know in SE20: the Alexandra Cottages, the Penge High Street area, Maple Road and the Anerley streets. Each road has its own building line, boundary treatment and precedent that Bromley Council weighs when assessing a rear dormer drawings scheme.
Conservation areas: Alexandra Cottages, Penge High Street, Crystal Palace Park. Inside these, most external work needs full planning and a Heritage Statement.
Getting around SE20: Penge West and Anerley on the Overground, plus Penge East and Kent House rail.
Property values: around £300,000 for a flat and £500,000-£800,000 for a house — a useful gauge of the build value an extension or loft adds in SE20.
Borough character: Largest London borough by area; substantial Green Belt; conservation areas in most town centres; generally permissive elsewhere.
We confirm whether your Anerley rear dormer qualifies for Permitted Development — checking volume limits (40m³ terraced, 50m³ semi/detached), Article 4, conservation area and prior extension history.
If PD applies, we obtain a Lawful Development Certificate for certainty. If not, we submit full planning with Design & Access Statement to Bromley Council.
Full-width flat-roof rear dormer with matching materials, set in from party walls, cheeks clad to match existing roof — the design that Bromley Council approves most readily.
Part B fire escape (protected staircase, fire doors, smoke alarms), Part K staircase, Part L insulation, Part E acoustic separation.
Steel ridge beam, purlin supports, dormer framing, floor joist upgrade — chartered engineer sign-off for Building Control.
Most rear dormers in Anerley's terraced streets trigger Section 6 Party Wall notices. We draft, serve and coordinate the process.
Single planning or building-regs submission.
Planning + building regs + structural.
Listed, conservation or complex sites.
Yes. The Victorian and Edwardian terraces and villas around Maple Road and the Anerley streets suit side-return, rear and loft extensions, much of it within Permitted Development outside the conservation areas, confirmed with a Lawful Development Certificate. We confirm the route and draw to Bromley's checklist.
Alexandra Cottages is a conservation area of distinctive Victorian model-housing with strong uniform character, so external changes there are tightly assessed on materials and form. We design sympathetically and submit a full application with a Heritage Statement where the designation applies.
Usually yes outside the conservation areas — a rear dormer or L-shape within the volume allowance, confirmed by a Lawful Development Certificate. Inside the Alexandra Cottages or Penge High Street designations, roof changes need full planning. We confirm which applies to your road.
With SE20 houses around £500,000-£800,000, Penge offers some of the area's best period-home value, and a side-return or loft adds family space worth well above the build and drawing cost. The Overground link keeps demand strong, and our fixed fee keeps the professional cost predictable.
Our fixed fee for rear dormer drawings in Anerley starts at £1,225 — no hourly billing. With Anerley property at around £300,000 for a flat and £500,000-£800,000 for a house, the professional drawing fee is a small fraction of the value the work adds to SE20's victorian and edwardian terraces and villas around. Bromley Council charges its own statutory application fee on top (currently £258 for a householder planning application, £578 for a full application). We quote the drawings as one fixed price and the free site survey covers every SE20 address.
For a SE20 project across Penge, Anerley, Crystal Palace Park fringe, expect roughly 3–4 weeks from instruction to submission: week 1 the measured survey, weeks 2–3 the drawings and your revisions, then validation and the statutory determination by Bromley Council (8 weeks for a householder application). We carry the Anerley application through every officer query to the decision.
Anerley (SE20) sits primarily in Bromley, so applications are decided by Bromley Council. Article 4 in force in the borough: No. Conservation areas within SE20 include Alexandra Cottages, Penge High Street, Crystal Palace Park, where full planning and a Heritage Statement are required. We confirm the planning route for your exact address before quoting.
Almost always. Any structural work behind rear dormer drawings in Anerley — new openings, steel beams, loft floors, foundations — needs Building Regulations approval covering structure (Part A), fire escape (Part B) and insulation (Part L), submitted to Bromley Council Building Control or an approved inspector. On SE20's typically terraced and semi-detached stock, a Party Wall notice to adjoining neighbours is normally required before the steelwork. We coordinate both as part of the Complete package.
In value terms, yes. With Anerley (SE20) property at around £300,000 for a flat and £500,000-£800,000 for a house, a well-designed extension or loft typically returns more than it costs in added floor area and sale value, while our fixed drawing fee from £1,225 keeps the professional cost predictable. The bigger risk is an unapproved or non-compliant scheme — which is why council-ready drawings and a clean Building Control sign-off matter on SE20 homes.
From £840.
From £840.
From £1,225.
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From £995.
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Pick a slot that suits you. No obligation and no sales pressure — just straight answers on your planning route, fixed fee and timescale.
Every SE20 postcode district we draw in, the stock that dominates it and the authority that validates a rear dormer there. SE20 fees below are the statutory England rates for 2026, not rear dormer estimates.
| Postcode | Area | Dominant stock | What it means for a rear dormer |
|---|---|---|---|
| SE20 | Anerley / Penge | Victorian and Edwardian terraces | A rear dormer in Anerley / Penge may land with Bromley Council or Croydon Council — SE20 crosses the boundary, and the SE20 policies map decides it street by street. |
| SE20 | Penge | Victorian and Edwardian terraces | Penge sits inside SE20; rear dormer proposals here are determined by Bromley Council. |
| BR1 | Bromley / Bickley | Victorian terraces, Edwardian villas, post-war flats | Adjoining district to SE20, also inside Bromley for rear dormer purposes. |
| BR2 | Hayes / Keston | Victorian terraces, Edwardian villas, post-war flats | Adjoining district to SE20, also inside Bromley for rear dormer purposes. |
| BR3 | Beckenham | Edwardian villas, 1930s semi-detached | Adjoining district to SE20, also inside Bromley for rear dormer purposes. |
| SE19 | Upper Norwood / Crystal Palace | Victorian villas, Edwardian terraces | Adjoining district to SE20, also inside Croydon for rear dormer purposes. |
| SE25 | South Norwood / Selhurst | Victorian terraces | Adjoining district to SE20, also inside Croydon for rear dormer purposes. |
| CR0 | Croydon / Addiscombe / Shirley | Edwardian terraces, post-war flats | Adjoining district to SE20, also inside Croydon for rear dormer purposes. |
| CR2 | South Croydon | mixed stock | Adjoining district to SE20, also inside Croydon for rear dormer purposes. |
Roof pitch, wall build-up and plot depth change every few SE20 streets, and each one changes what a rear dormer can achieve at that address.
SE20 (Anerley / Penge) conservation designations: there are 48 across Bromley Council, Beckenham, Keston, Bickley among them. Designation costs a SE20 (Anerley / Penge) owner the permitted-development route: a rear dormer then needs a £258 householder application over 8 weeks, in place of the £120 prior approval route that takes 6 weeks. Chislehurst is the SE20 (Anerley / Penge) designation that most often changes a rear dormer design.
No blanket Article 4 over SE20 (Anerley / Penge): Bromley Council has not withdrawn permitted development across SE20 (Anerley / Penge), so a rear dormer outside a SE20 (Anerley / Penge) conservation area usually keeps it. The £129 Lawful Development Certificate is still the document a SE20 owner wants on file.
What SE20 (Anerley / Penge) is built from: Large 1930s detached and semi-detached in Chislehurst and Bickley; Edwardian in Beckenham; Victorian in Bromley town; Metropolitan Green Belt covers significant rural-fringe land. Largest London borough by area; substantial Green Belt; conservation areas in most town centres; generally permissive elsewhere. That mix decides the rear dormer route in SE20 (Anerley / Penge) more than the postcode does. Our fixed fee for rear dormers in SE20 (Anerley / Penge) starts at £1,225, against £1,750 for the Complete package that carries a SE20 (Anerley / Penge) scheme through Bromley Council planning and building regulations together.
SE20 (Anerley / Penge) conservation designations: there are 24 across Croydon Council, Old Coulsdon, Purley, Shirley Park among them. Designation costs a SE20 (Anerley / Penge) owner the permitted-development route: a rear dormer then needs a £258 householder application over 8 weeks, in place of the £120 prior approval route that takes 6 weeks. Crystal Palace is the SE20 (Anerley / Penge) designation that most often changes a rear dormer design.
No blanket Article 4 over SE20 (Anerley / Penge): Croydon Council has not withdrawn permitted development across SE20 (Anerley / Penge), so a rear dormer outside a SE20 (Anerley / Penge) conservation area usually keeps it. The £129 Lawful Development Certificate is still the document a SE20 owner wants on file.
What SE20 (Anerley / Penge) is built from: Victorian villas in Upper Norwood and Crystal Palace; Edwardian terraces in Thornton Heath and Selhurst; 1930s semi-detached in Purley and Coulsdon; post-war in Croydon central. Large, mixed-density outer borough; permissive in outer areas; heritage controls in conservation pockets; major regeneration in central Croydon. That mix decides the rear dormer route in SE20 (Anerley / Penge) more than the postcode does. Our fixed fee for rear dormers in SE20 (Anerley / Penge) starts at £1,225, against £1,750 for the Complete package that carries a SE20 (Anerley / Penge) scheme through Croydon Council planning and building regulations together.
Sources for this SE20 rear dormer page: borough policies maps and conservation-area registers (2025–26), Royal Mail postcode district boundaries, the Town and Country Planning (Fees for Applications) (England) Regulations, the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended, and the Party Wall etc. Act 1996.
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