New Cross · SE14 · Lewisham

Rear Extension Drawings in New Cross SE14

Fixed-fee, MCIAT-chartered rear extension drawings for New Cross (SE14) homeowners — London Borough of Lewisham validation and local constraints handled from the start.

New Cross (SE14) climbs from the busy New Cross Road up into the Victorian streets of Telegraph Hill and the terraces behind Hatcham, and our work here is mostly rear extensions, side returns and loft conversions on that period housing.

Both the Telegraph Hill and Hatcham conservation areas carry Article 4 directions, so several normally-permitted changes need consent, and we check the boundary and the direction before advising on a permitted-development or full householder route.

Proposed floor plan

New Cross SE14

New Cross (SE14) — planning at a glance

Council: London Borough of Lewisham
Postcode district: SE14
Planning portal: View the Lewisham planning portal
Housing stock: Telegraph Hill is a largely residential grid of steep Victorian streets and villas above New Cross, while Hatcham combines commercial frontages on New Cross Road with Victorian terraces behind, plus later flats and student housing.
Article 4: Lewisham has Article 4 directions for both the Telegraph Hill and Hatcham conservation areas in SE14, removing some permitted-development rights so certain external alterations need planning permission.
Conservation: Telegraph Hill Conservation AreaHatcham Conservation Area
Sample streets: Pepys Road · Jerningham Road · Kitto Road · Erlanger Road
Local constraints: Article 4 directions in the Telegraph Hill and Hatcham conservation areas restrict permitted-development changes to elevations.Steep hillside streets and consistent Victorian building lines constrain extension height and massing.Original sash windows, front garden walls and roofscape are protected features on the Telegraph Hill stock.

Planning in New Cross (SE14): what to know before you apply

Inside the Telegraph Hill or Hatcham conservation areas the Article 4 directions mean front-facing and roof changes usually need planning permission. We confirm the designation for your street and prepare drawings to Lewisham standards.

Typical New Cross housing stock

Telegraph Hill is a largely residential grid of steep Victorian streets and villas above New Cross, while Hatcham combines commercial frontages on New Cross Road with Victorian terraces behind, plus later flats and student housing.

Streets we regularly draw for in New Cross

Pepys Road · Jerningham Road · Kitto Road · Erlanger Road

What SE14 is actually built of

Measured from 196 classified residential buildings in SE14, not from a description of the area.

New Cross SE14 housing mix

Residential building form across the SE14 postcode district, from 196 classified buildings.

Attached on more than one side	71%
Attached on one side	27%
Detached	2%
Median building footprint	63 m²
Addresses per buildingAbove about 2 means flats and maisonettes dominate	2.19
Buildings classified	196

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 New Cross (SE14) 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 New Cross property in SE14, showing the existing and proposed arrangement at scale — A sheet from the rear extension drawings package we submit to London Borough of Lewisham for New Cross (SE14) properties.

Also in New Cross SE14

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

FAQ

Rear Extension Drawings in New Cross SE14 — 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 a side-return extension in Lewisham?+

On the Victorian and Edwardian terraces of Brockley, Forest Hill and Hither Green a single-storey side-return or rear extension can fall within permitted development, so a full application isn't always needed. Conservation areas such as Blackheath, Brockley and Telegraph Hill restrict this. We check your street's designation first and can confirm permitted development with a Lawful Development Certificate where it qualifies.

What does Lewisham's borough-wide HMO Article 4 direction affect?+

Lewisham applies a borough-wide Article 4 direction removing permitted development rights for change of use to an HMO (C3 to C4), so a conversion to a house in multiple occupation needs a full application anywhere in the borough. It doesn't affect a standard family extension or loft, but we confirm whether it applies to your intended use before advising on a route.

Can I convert the loft on my Lewisham terrace?+

Usually, yes. The terraces of Brockley, Forest Hill and Hither Green suit hip-to-gable and dormer loft conversions, which frequently qualify as permitted development within the volume limits. Outside the conservation areas this is often the quickest route. We confirm eligibility against those limits and any designation, then produce the planning and building-regulations drawings.

How long does Lewisham Council take to decide?+

Lewisham determines most householder applications within the statutory eight-week period once validated; conservation cases can attract additional consultation. The dense terraced streets are party-wall-sensitive, so the commonest delay is a drawing query — we prepare submissions to the council's validation checklist to keep them moving.

How much do planning drawings cost in Lewisham?+

We agree a fixed fee before starting, usually around 30% below an architect's fee for the same council-accepted drawings, with free redraws until Lewisham approves. A side-return, a loft and a conservation-area scheme differ in complexity, so we quote once we understand your street and project rather than charging by the hour.

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