Kitchen rear extension in a Victorian terrace in Penge SE20, London Borough of Bromley

Penge · SE20 · Bromley

Side Return Extension Drawings in Penge SE20

Fixed-fee, MCIAT-chartered side return extension drawings for Penge (SE20) homeowners — London Borough of Bromley validation and local constraints handled from the start.

Penge (SE20) in Bromley is a compact Victorian neighbourhood between its High Street and Crystal Palace Park, with a conservation area centred on the High Street and its notable listed almshouses. Rear and loft projects on the Victorian terraces are the mainstay, worked around those local controls.

The Penge High Street conservation area protects the historic centre, including the listed almshouses, and the tight Victorian terrace plots on many streets shape how far a rear extension can practically go. We check a Penge address against the conservation area and the terrace context before drawing to Bromley's residential guidance.

Proposed floor plan

Penge SE20

Penge (SE20) — planning at a glance

Council: London Borough of Bromley
Postcode district: SE20
Planning portal: View the Bromley planning portal
Housing stock: Victorian terraces and villas on the streets between Penge High Street and Crystal Palace Park, including the listed almshouses on the High Street, with later interwar and post-war housing toward Anerley.
Article 4: London Borough of Bromley does not publish its Article 4 directions to the national planning register, so permitted development rights in Penge (SE20) 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. The Penge High Street conservation area, with its listed almshouses, is the defining local control.
Conservation: Penge High Street
Sample streets: Penge High Street · Maple Road · Croydon Road · Anerley Road
Local constraints: Penge High Street conservation area, which includes the listed Watermen's and King William IV Naval almshousesTight Victorian terrace plots limiting extension depth on parts of the districtThe setting of Crystal Palace Park to the north, with mature trees under Tree Preservation Orders

Planning in Penge (SE20): what to know before you apply

SE20 has no householder Article 4 direction, so many Penge terraces retain permitted development rights for rear and loft projects — but the Penge High Street conservation area, with its listed almshouses, closely controls the historic centre, and the tight Victorian terrace plots limit extension depth on several streets. The nearby Crystal Palace Park setting adds tree and townscape considerations.

Typical Penge housing stock

Victorian terraces and villas on the streets between Penge High Street and Crystal Palace Park, including the listed almshouses on the High Street, with later interwar and post-war housing toward Anerley.

Streets we regularly draw for in Penge

Penge High Street · Maple Road · Croydon Road · Anerley Road

What SE20 is actually built of

Measured from 192 classified residential buildings in SE20, not from a description of the area.

Penge SE20 housing mix

Residential building form across the SE20 postcode district, from 192 classified buildings.

Attached on more than one side	55%
Attached on one side	38%
Detached	7%
Median building footprint	58 m²
Addresses per buildingAbove about 2 means flats and maisonettes dominate	1.99
Buildings classified	192

Source: Ordnance Survey National Geographic Database (derived statistics). Contains OS data © Crown copyright and database right 2026. Contains Royal Mail data © Royal Mail copyright and database right 2026. Extracted 2026-08-17.

Side Return Extension Drawings for Penge (SE20) 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 drawn for a Penge property in SE20, showing the existing and proposed arrangement at scale — A sheet from the side return extension drawings package we submit to London Borough of Bromley for Penge (SE20) properties.

Also in Penge SE20

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

FAQ

Side Return Extension Drawings in Penge SE20 — 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.

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