Rear Extension Drawings in Bromley
Fixed-fee, MCIAT-chartered rear extension drawings for Bromley homeowners — London Borough of Bromley validation and local constraints handled from the start.
As London's largest borough by area, Bromley offers the generous interwar detached and semi-detached plots that make substantial rear and double-storey extensions genuinely viable. The housing stock runs from suburban semis around Beckenham, Penge and West Wickham to larger detached homes and edge-of-London properties toward Orpington, Hayes and Chislehurst. The right Bromley application is usually about maximising a large plot within policy rather than squeezing a tight terrace, and the room to build is exactly why so many owners here extend rather than move.
Two constraints shape what is achievable. Green-belt designation across the borough's outer edges restricts the scale of additions on properties toward Orpington and Chislehurst, where extensions are assessed against strict limits on disproportionate additions to the original dwelling. Conservation control in Chislehurst, Keston, Hayes, Park Langley and Bromley Town governs materials and design in those areas. Bromley has no borough-wide Article 4 direction affecting typical householder permitted development, so detached homes here often retain fuller rights than inner-London terraces, which we always check first.
We prepare Bromley planning drawings that use the available plot fully while respecting green-belt and conservation constraints, confirming permitted development limits for detached and semi-detached homes before we draw and evidencing green-belt cases carefully where they apply. Because the plots allow larger schemes, we design to the project rather than a standard template, and we agree a fixed fee up front, typically around 30% below an architect's charge for the same council-accepted drawings, with free redraws until Bromley approves. The council determines most householder applications within the statutory eight-week period once validated, so a complete, correctly scaled, validation-first submission is the best way to hold that timescale.
Planning in Bromley: what to know before you apply
Bromley has no borough-wide Article 4 direction affecting typical householder permitted development; the binding constraints are green-belt policy on outer properties and conservation-area control in Chislehurst, Keston and Bromley Town. Detached homes here often retain fuller permitted development rights than inner-London terraces.
Typical Bromley housing stock
Large interwar detached and semi-detached houses with generous plots, plus green-belt and edge-of-London properties toward Orpington and Chislehurst.
Areas we regularly draw for in Bromley
Bromley · Beckenham · Orpington · Chislehurst · Penge · Hayes · West Wickham
What the numbers say about Bromley planning decisions
These are London Borough of Bromley’s own reported figures, published by government rather than estimated by us. They are what we design against — a borough that refuses one householder application in five needs a different drawing package from one that refuses one in twenty.
Permitted development in Bromley
Larger householder extensions put to London Borough of Bromley under the prior-approval route, and lawful-development certificates decided, over eight quarters.
| Prior approval not requiredWent ahead without a full application | 201 |
|---|---|
| Prior approval granted | 11 |
| Prior approval refused | 23 |
| Granted where a decision was neededFrom 34 determinations | 32% |
| Building upwards, prior approval refused | 5 |
| Certificates of lawful development decided | 1,010 |
Source: Ministry of Housing, Communities and Local Government (PS1 district planning application statistics). Open Government Licence v3.0 Extracted 2026-08-16.
What removes permitted development in Bromley
Live entries on the national planning registers for London Borough of Bromley. Article 4 directions withdraw permitted development rights, so a project inside one needs a full application rather than prior approval. Revoked and expired entries are excluded.
| Article 4 directions in force | 108 |
|---|---|
| Conservation areasPermitted development is already narrower inside one | 69 |
Source: MHCLG Planning Data Platform. Open Government Licence v3.0 Extracted 2026-08-16.
Rear Extension Drawings for Bromley homes: the package and the process
Depth is the number the application turns on, and it has to be measured from the original rear wall of the house rather than from whatever is there now. The drawings carry that dimension, the eaves and ridge heights, the position of any rooflight, and the boundary distances on both sides.
Where the scheme goes beyond the standard allowance and relies on the larger home extension route, the drawings serve a second purpose: they are what the council sends to the neighbours during the consultation. A clear, dimensioned proposed elevation answers the objection about overshadowing before it is made.
Depth is limited by the plot as much as by the rules. A long garden behind a terrace can take the full allowance, while a short one runs out before the rules do — and on a semi or detached house the same depth reads very differently from the boundary.
Do I need planning permission for a rear extension in London?
Many single-storey rear extensions qualify as permitted development, meaning no planning application is needed, provided depth, height and materials stay within set limits. That changes if your property sits in a conservation area or is subject to an Article 4 direction, both of which can remove permitted development rights across a street or borough — in that case a full householder planning application is required regardless of size.
Even where an extension qualifies, most homeowners obtain a Lawful Development Certificate to confirm that status in writing before building — useful for mortgage lenders, buyers and Building Control. We check your property against your borough's constraints before recommending a route.
How deep can a single-storey rear extension go?
Depth is the main constraint on a rear extension, and it depends on your house type and whether you use standard permitted development or the larger home extension scheme.
Permitted development
Standard permitted development allows a single-storey rear extension up to 3 metres deep for terraced and semi-detached houses, or 4 metres for detached houses, generally with eaves height limited to match or stay close to the existing house.
Larger home extension scheme
The prior-approval scheme extends this to 6 metres for terraced and semi-detached houses and 8 metres for detached houses. Your council writes to affected neighbours; if none object within the notification period, approval follows without a full planning application. If an objection is raised, the council assesses the impact on neighbouring light and outlook itself, rather than automatically refusing, so a well-considered design still has a good chance of approval.
Designing the kitchen-diner: rooflights, bi-folds and daylight
Most rear extensions exist to create one open-plan kitchen, dining and living space, so the drawing work focuses on getting light and flow right within the depth you are allowed.
- Structural opening sized for bi-fold or sliding doors across most of the rear elevation
- Rooflights or a roof lantern positioned to light the centre of the room, away from the shadow line of the main house
- Open-plan layout tested against the 45-degree rule, which protects daylight to your neighbours' windows and can limit how close a flank wall or roof comes to the boundary
- Floor build-up and threshold detail coordinated so the new floor meets the existing one without a step
| Route | When it applies | Typical fee |
|---|---|---|
| Permitted development (Lawful Development Certificate) | Depth within 3m (terraced/semi) or 4m (detached), height and materials within PD limits | PD/LDC pack ~£950–£1,450 |
| Larger home extension (prior approval) | Depth up to 6m (terraced/semi) or 8m (detached), with neighbour notification | from £1,100 |
| Full householder planning permission | Extension exceeds PD/larger-home limits, or the property is in a conservation area with an Article 4 direction | Full Planning pack ~£1,600–£2,400 |
| Planning + Building Regulations (structural) | Combined planning and construction-ready pack with structural calculations for the opening and roof | Planning + Building Regs pack ~£2,200–£3,850 |
Rear Extension Drawings across Bromley
Rear Extension Drawings in Bromley — FAQs
How much does a rear extension cost to design in London?+
Do I need an architect for a rear extension?+
How long does it take to get rear extension drawings?+
What is the 45-degree rule?+
Will I need a Party Wall Agreement for a rear extension?+
Do I need planning permission for an extension in Bromley?+
Can I build a bigger extension because Bromley plots are larger?+
How does green-belt designation affect my Bromley project?+
How long does Bromley Council take to decide?+
How much do planning drawings cost in Bromley?+
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