Basement conversion drawings for a Victorian villa in Hampstead NW3, London Borough of Camden

Hampstead · NW3 · Camden

Rear Extension Drawings in Hampstead NW3

Fixed-fee, MCIAT-chartered rear extension drawings for Hampstead (NW3) homeowners — London Borough of Camden validation and local constraints handled from the start.

Hampstead (NW3) is, in permitted-development terms, close to a special case. Three conservation areas cover the district — Hampstead, Belsize and Fitzjohns/Netherhall — and Camden has attached a non-immediate Article 4 direction to each of them, on top of the borough-wide Basements direction. The practical effect is that very little in NW3 proceeds under permitted development.

That reshapes what a project looks like here. Basement works need a full application under the Basements direction; the non-immediate Article 4 directions across Hampstead (excluding Frognal Way), Belsize and Fitzjohns/Netherhall strip further rights inside those conservation areas; the village core carries a very high concentration of listed buildings needing listed building consent alongside planning; and because so many of the large Fitzjohns Avenue and Belsize Park villas were long ago converted into flats, a large share of NW3 work is flat alteration — where permitted development rights do not exist in the first place. We establish the designation, listing and tenure position for an NW3 address before drawing to Camden's guidance.

Proposed floor plan

Hampstead NW3

Hampstead (NW3) — planning at a glance

Council: London Borough of Camden
Postcode district: NW3
Planning portal: View the Camden planning portal
Housing stock: Georgian houses in the old village core, substantial Victorian red-brick villas along Fitzjohns Avenue and Netherhall Gardens, and large Victorian semi-detached and terraced houses through Belsize Park, much of it converted to flats.
Article 4: BasementsBelsize Conservation Area (various properties)Belsize Conservation Area Non-immediate Article 4Fitzjohns/Netherhall Conservation Area Non-immediate Article 4Hampstead Conservation Area (excl. Frognal Way) Non-immediate Article 4
Conservation: BelsizeFitzjohns NetherhallHampstead
Sample streets: Hampstead High Street · Fitzjohns Avenue · Netherhall Gardens · Belsize Park Gardens
Local constraints: Camden's Basements Article 4 direction removing permitted development rights for basement works across the districtNon-immediate Article 4 directions across all three conservation areas — Hampstead (excluding Frognal Way), Belsize and Fitzjohns/Netherhall — removing further permitted development rightsA very high concentration of listed buildings in the village core, where listed building consent is needed alongside planningExtensive conversion of the large villas into flats, so many projects are flat alterations with no permitted development rights at all

Planning in Hampstead (NW3): what to know before you apply

NW3 is one of the most heavily restricted districts in London for householder work. Camden's Basements Article 4 direction removes permitted development rights for basement schemes, and non-immediate Article 4 directions apply across all three conservation areas — Hampstead (excluding Frognal Way), Belsize and Fitzjohns/Netherhall — removing further rights inside them. The village core has a very high concentration of listed buildings requiring listed building consent, and the widespread conversion of the large villas into flats means many NW3 projects have no permitted development rights regardless of designation. Assume a full application in NW3.

Typical Hampstead housing stock

Georgian houses in the old village core, substantial Victorian red-brick villas along Fitzjohns Avenue and Netherhall Gardens, and large Victorian semi-detached and terraced houses through Belsize Park, much of it converted to flats.

Streets we regularly draw for in Hampstead

Hampstead High Street · Fitzjohns Avenue · Netherhall Gardens · Belsize Park Gardens

Rear Extension Drawings for Hampstead (NW3) homes: the package and the process

Every rear extension drawings we prepare for an Hampstead property is drawn to London Borough of Camden’s validation standards and tuned to the NW3 constraints above. Here is what the drawing package covers and how the process runs from first survey to approval.

A single-storey rear extension is the most common way London homeowners add space, usually taking the form of an open-plan kitchen-diner that opens onto the garden through bi-fold or sliding doors, with rooflights or a roof lantern bringing daylight deep into the plan. Because depth and height are tightly controlled by permitted development rules and by the 45-degree rule that protects neighbouring windows, the design work sits as much in checking what the council will allow as in drawing what you want.

DrawingsDirect draws rear extensions for permitted development, the larger home extension prior-approval scheme and full householder planning, with structural calculations for the opening and roof produced in-house by our MCIAT-chartered team. If your project also involves widening the kitchen sideways or adding a second storey, see our Side Return, Wraparound and Double Storey Extension pages — many London rear extensions grow into one of those during design.

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.

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

Also in Hampstead NW3

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

FAQ

Rear Extension Drawings in Hampstead NW3 — 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 rear extension in Camden?+

Frequently, yes. Much of Camden sits within a conservation area or is listed, and near-borough-wide conservation coverage removes permitted development for many external works. On unlisted homes outside a conservation area a rear extension may still qualify, but in Hampstead, Belsize Park and Primrose Hill a full application is usually needed. We confirm the exact constraints for your address before drawing.

What is a Basement Impact Assessment and will I need one in Camden?+

Camden operates one of the most rigorous basement policies in London. Schemes involving a basement or lower-ground extension generally require a Basement Impact Assessment addressing structural stability, drainage and groundwater. If you are considering below-ground space we flag the requirement early and coordinate the assessment so the application is complete when it is submitted.

Can I make changes to a listed building in Camden?+

Often, but listed-building consent is usually required alongside — or instead of — planning permission, and internal as well as external changes can be controlled. Camden has a high density of listed buildings in Hampstead, Bloomsbury and Fitzrovia. We screen listing status for your address first and prepare the heritage-led drawings and justification the council expects.

How long does Camden take to decide an application?+

Camden determines most householder applications within the statutory eight-week period once validated; basement, conservation and listed-building cases can involve additional consultation. We prepare Camden submissions to the council's validation and design standards to avoid the drawing queries that cause most delays.

How much do planning drawings cost in Camden?+

We agree a fixed fee before we start, typically around 30% below an architect's fee for the same council-accepted drawings, with free redraws until Camden approves. A conservation-area rear extension, a basement and a listed-building scheme differ in the evidence required, so we quote once we have seen your project rather than by the hour.

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