Loft conversion bedroom with skylights in a 1930s Coulsdon CR5 semi, Croydon

Coulsdon · CR5 · Croydon

Rear Extension Drawings in Coulsdon CR5

Fixed-fee, MCIAT-chartered rear extension drawings for Coulsdon (CR5) homeowners — Croydon Council validation and local constraints handled from the start.

Coulsdon CR5, and Old Coulsdon in particular, pairs an historic village core around Bradmore Green with streets of interwar 1930s semis, where rear and side extensions and loft conversions are the common ways families extend.

The Bradmore Green Conservation Area removes several permitted development rights near the green, so even though Croydon has no Article 4 directions, we check whether a property falls inside that boundary before choosing permitted development over a full application.

Proposed floor plan

Coulsdon CR5

Coulsdon (CR5) — planning at a glance

Council: Croydon Council
Postcode district: CR5
Planning portal: View the Croydon planning portal
Housing stock: The heart of Old Coulsdon around Bradmore Green and Grange Park keeps an older village character, wrapped by the interwar and 1930s semi-detached houses that make up much of the wider CR5 stock, most with side and rear scope for extension.
Article 4: Croydon operates no current Article 4 directions, so permitted development rights are retained across Coulsdon CR5 except where a property sits inside a conservation area, which removes several rights on its own.
Conservation: Bradmore Green Conservation Area
Sample streets: Coulsdon Road · Bradmore Way · Canons Hill · Fairdene Road
Local constraints: Bradmore Green Conservation Area protects the open green and its surrounding buildings, so alterations facing the green are assessed for character impactInside the conservation area most external alterations need full planning from Croydon rather than proceeding as permitted developmentThe mix of an historic village core with interwar semis means extension scale and roof form are judged against differing established patterns street by street

Planning in Coulsdon (CR5): what to know before you apply

Coulsdon homes outside the conservation area often retain permitted development for rear extensions and lofts, while those inside Bradmore Green usually need full householder applications to Croydon. Croydon runs no Article 4 directions. We confirm the boundary and roof form before advising a route.

Typical Coulsdon housing stock

The heart of Old Coulsdon around Bradmore Green and Grange Park keeps an older village character, wrapped by the interwar and 1930s semi-detached houses that make up much of the wider CR5 stock, most with side and rear scope for extension.

Streets we regularly draw for in Coulsdon

Coulsdon Road · Bradmore Way · Canons Hill · Fairdene Road

What CR5 is actually built of

Measured from 336 classified residential buildings in CR5, not from a description of the area.

Coulsdon CR5 housing mix

Residential building form across the CR5 postcode district, from 336 classified buildings.

Attached on more than one side	23%
Attached on one side	44%
Detached	33%
Median building footprint	81 m²
Addresses per buildingAbove about 2 means flats and maisonettes dominate	1.12
Buildings classified	336

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.

Rear Extension Drawings for Coulsdon (CR5) 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

Rear extension routes at a glance
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

Sheet from a rear extension drawings package drawn for a Coulsdon property in CR5, showing the existing and proposed arrangement at scale — A sheet from the rear extension drawings package we submit to Croydon Council for Coulsdon (CR5) properties.

Also in Coulsdon CR5

Planning Permission Planning Drawings Architectural Drawings Building Regulations Drawings Loft Conversion Drawings Rear Extension Drawings across Croydon Rear Extension Drawings across London

FAQ

Rear Extension Drawings in Coulsdon CR5 — FAQs

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

Rear extension drawings start from £1,100, with the final fee set by the route your extension takes — permitted development, prior approval or full planning — and whether you need building regulations and structural calculations bundled in. The fee is fixed and agreed upfront.

Do I need an architect for a rear extension?+

No. DrawingsDirect is an MCIAT-chartered architectural technologist practice, producing the same council-accepted drawings as an architect for a fixed fee typically around 30% lower.

How long does it take to get rear extension drawings?+

Drawings are typically ready around 7 days from survey. Once submitted, councils have a statutory 8-week period to determine a standard householder planning application.

What is the 45-degree rule?+

It is a daylight test many London councils apply to check that a rear extension does not block too much light to a neighbour's nearest window, measured as a line drawn at 45 degrees from that window. We check it before submission, not after a refusal.

Will I need a Party Wall Agreement for a rear extension?+

Only if your foundations or new walls sit on or near the boundary with a neighbouring property. A straightforward rear extension set within your own plot often does not trigger the Party Wall etc. Act 1996, unlike a Side Return or Wraparound extension, which usually does.

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

It depends where in the borough you are. The interwar semis and detached homes of Purley, Sanderstead and Coulsdon often keep fuller permitted development rights than inner-London terraces, so larger rear and single-storey extensions can qualify. Conservation areas such as Addiscombe and South Norwood, and HMO Article 4 wards, restrict this. We check your address first and can confirm permitted development with a Lawful Development Certificate.

Can I build a larger extension on a Purley or Sanderstead plot?+

Often, yes. Croydon's generous suburban plots make substantial rear and double-storey extensions viable where a tight terrace could not accommodate them. The limit is usually design and amenity policy rather than space. We design to use the plot fully within permitted-development allowances or a well-evidenced full application, checking the limits for detached and semi-detached homes first.

What do Croydon's HMO Article 4 directions mean for me?+

In designated wards, an Article 4 direction removes permitted development for change of use to an HMO (C3 to C4), so a conversion to a house in multiple occupation needs a full application there. It doesn't affect a standard family extension, but if you are considering an HMO we confirm whether the direction covers your address and use before advising on a route.

How long does Croydon Council take to decide?+

Croydon determines most householder applications within the statutory eight-week period once validated. As a large borough spanning terraces to suburban plots, a complete, correctly scaled submission is the best way to avoid a validation query — we prepare Croydon drawings to the council's checklist to keep the application on track.

How much do planning drawings cost in Croydon?+

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

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