Detached London brick house with garage and driveway, characteristic of Bromley's suburban plots

Bromley · London

Side Return Extension Drawings in Bromley

Fixed-fee, MCIAT-chartered side return 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.

Proposed floor plan

Bromley

London Borough of Bromley — planning at a glance

Council: London Borough of Bromley
Planning portal: View the Bromley planning portal
Housing stock: Large interwar detached and semi-detached houses with generous plots, plus green-belt and edge-of-London properties toward Orpington and Chislehurst.
Typical decision: ~8 weeks for householder applications
Article 4: London Borough of Bromley does not publish its Article 4 directions to the national planning register, so permitted development rights in Bromley can’t be confirmed from open data alone — we check the direction schedule with the council before recommending a route, as part of the fixed fee. Green-belt and conservation controls dominate the borough.
Conservation: Bromley TownChislehurstKestonHayesPark Langley
Local constraints: Green-belt policy restricting scale on outer propertiesGenerous plots that allow larger extensions than inner boroughsConservation control in Chislehurst and Keston

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.

Side Return Extension Drawings for Bromley homes: the package and the process

A side return is a structural drawing as much as a planning one. Removing the original flank wall to open the kitchen into the infill needs a beam and a padstone detail, and the new roof has to be drawn where it meets both the existing rear elevation and the boundary wall.

The boundary is the sensitive line. The drawings set out where the new wall sits relative to it, how the roof drains without discharging next door, and where rooflights fall so the officer can see the room is lit without overlooking. That detail is also what your party wall surveyor will ask for.

The extension only exists where the alley does. Mid-terrace and end-of-terrace houses with a rear outrigger are the classic case; a semi with a flank path is a different scheme with different boundary questions; and a detached house has no side return to infill at all.

Do I need planning permission for a side return extension in London?

Permitted development rights for side extensions are narrower than for rear extensions: they generally cap the extension at a single storey, restrict its width to no more than half the width of the original house, and limit its height. In practice, a full-depth side return running the length of a Victorian or Edwardian terrace usually exceeds one or more of these limits, so most side return projects are drawn and submitted as a full householder planning application.

Conservation area status and Article 4 directions, common across inner London terraces, remove permitted development rights for side extensions entirely in many streets, reinforcing the need for a planning application. We check your property's status before drawing.

What does a side return extension involve?

A side return infills the alley at ground floor level, structurally opening the original flank wall of the kitchen into the new space so the two areas read as one room. Unlike a rear extension, which is bounded on three sides by your own garden, a side return is bounded on one long side by the neighbouring property, which shapes almost every decision in the design, from where the roof glazing sits to how deep the new foundations need to go.

New flank wall built out to align with the rear of the house, following the boundary line
Original external wall between kitchen and alley opened up and supported on a steel or glulam beam
Roof over the new space either glazed in full, glazed in a strip along the boundary for a 'light well' effect, or pitched and tiled to match the main roof
Kitchen re-planned across the combined footprint, often incorporating an island once the room widens

Will I need a Party Wall Agreement for a side return extension?

Almost certainly. Because the new side wall is built on or immediately against the boundary with the neighbouring property, the Party Wall etc. Act 1996 applies, and your neighbour must be formally notified before work starts. We prepare the drawings and dimensions your Party Wall surveyor needs, and time the notice period so it runs alongside, rather than after, your planning application.

Side return project options
Package	What it covers	Typical fee
Side return, planning only	Full householder planning application drawings for the infill	Full Planning pack ~£1,600–£2,400
Side return, planning + Building Regulations	Adds structural calculations, Party Wall drawings and construction detail	Planning + Building Regs pack ~£2,200–£3,850
Side return + rear extension (wraparound)	Combines both extensions into one L-shaped ground floor	see Wraparound Extension Drawings
Measured survey only	A measured existing floor-plan set for your own architect, surveyor or builder	from £450

Sheet from a side return extension drawings package prepared for a Bromley property, drawn to London Borough of Bromley validation standards — A sheet from the side return extension drawings package we submit to London Borough of Bromley.

Local Areas

Side Return Extension Drawings across Bromley

Also in Bromley

Planning Permission Planning Drawings Architectural Drawings Building Regulations Drawings Loft Conversion Drawings Side Return Extension Drawings across London

FAQ

Side Return Extension Drawings in Bromley — FAQs

How much does a side return extension cost to design in London?+

Side return drawings start from £1,400. The final fee depends on whether you commission planning drawings alone or a combined planning and building regulations package with structural calculations, all fixed and agreed upfront.

Can I build a side return under permitted development?+

Rarely for a full-width, full-depth side return. Permitted development for side extensions is limited on width and storeys, and most Victorian and Edwardian terraces sit in conservation areas that remove these rights anyway, so a full planning application is the usual route. We still check your specific property first, since some semi-detached and detached houses outside conservation areas retain more generous side-extension allowances.

When do I need to serve Party Wall notice on my neighbour?+

Before work starts, and ideally once your drawings and structural design are settled, since the notice needs accurate dimensions. We can prepare the supporting drawings alongside your planning application so both processes run in parallel.

Do I need an architect for a side return extension?+

No. DrawingsDirect is an MCIAT-chartered architectural technologist practice, so you get the same council-accepted drawings as an architect, for a fixed fee typically around 30% lower, with structural calculations produced in-house.

How long does a side return extension take to design and approve?+

Drawings are typically ready around 7 days from survey. A householder planning application then has a statutory 8-week determination period, running alongside your Party Wall notice period.

Do I need planning permission for an extension in Bromley?+

Bromley has no borough-wide Article 4 direction affecting typical householder permitted development, so its detached and semi-detached homes often keep fuller rights than inner-London terraces — larger rear and single-storey extensions can qualify. The binding constraints are green-belt policy on outer properties and conservation control in Chislehurst, Keston and Bromley Town. We check both and can confirm permitted development with a Lawful Development Certificate.

Can I build a bigger extension because Bromley plots are larger?+

Often, yes. Bromley's generous interwar plots make substantial rear and double-storey extensions viable where an inner-London terrace could not accommodate them. The limit is usually policy rather than space — green belt restricts scale on outer properties, and conservation areas control design. We design to use the plot fully within those limits, checking permitted-development allowances for detached homes first.

How does green-belt designation affect my Bromley project?+

On green-belt properties toward Orpington, Chislehurst and the borough's edges, extensions are assessed against strict limits on disproportionate additions to the original dwelling. It does not rule out an extension, but scale and siting matter and the case must be evidenced carefully. We confirm whether your property is green belt and design a scheme that stays within policy.

How long does Bromley Council take to decide?+

Bromley determines most householder applications within the statutory eight-week period once validated. As London's largest borough by area, its casework spans suburban semis to green-belt properties, so a complete, correctly scaled submission is the best way to avoid a validation query and keep to that timescale.

How much do planning drawings cost in Bromley?+

We quote a fixed fee upfront, typically around 30% below an architect's charge for the same council-accepted drawings, with free redraws until Bromley approves. Because plots here allow larger schemes, the fee tracks the project's complexity — a single-storey rear differs from a double-storey or a green-belt case — and we confirm it once we understand your plans.

Free Fixed Quote

Get your free Bromley planning assessment

Tell us your Bromley address and ambition — we'll confirm feasibility, local constraints and a fixed fee within one working day.