Kitchen extension interior in a Hendon NW4 family home, Barnet

Hendon · NW4 · Barnet

House Extension Drawings in Hendon NW4

Fixed-fee, MCIAT-chartered house extension drawings for Hendon (NW4) homeowners — London Borough of Barnet validation and local constraints handled from the start.

Hendon (NW4) in Barnet ranges from the historic Church End village around St Mary's church to streets of Victorian and interwar houses, and the usual brief is a rear or side extension or a loft conversion to add family space.

The Hendon Church End conservation area protects the medieval church core, its listed buildings and the hilltop views, so if your home sits inside the boundary we check it first and steer massing and materials before deciding between permitted development and a full householder application.

Proposed floor plan

Hendon NW4

Hendon (NW4) — planning at a glance

Council: London Borough of Barnet
Postcode district: NW4
Planning portal: View the Barnet planning portal
Housing stock: A linear historic village around the medieval St Mary's parish church, where over half the buildings are residential, set among Victorian and interwar houses that make up the wider NW4 suburb.
Article 4: No Article 4 direction is confirmed for the Hendon Church End conservation area, so permitted-development rights are not withdrawn — but the designation still controls changes around the historic St Mary's church core and its listed buildings.
Conservation: Hendon Church End Conservation Area
Sample streets: Church Road · Church End · Greyhound Hill · Parson Street
Local constraints: Hendon Church End conservation area (designated 1983) centres on the 13th-century St Mary's church and hilltop views, so additions must protect the low-rise historic settingSeveral buildings in the area are listed or held by neighbouring Middlesex University, tightening control over adjacent worksThe elevated Church End ridge affords long views across the borough, so roof additions are assessed for their impact on the skyline

Planning in Hendon (NW4): what to know before you apply

Across the wider NW4 suburb, rear extensions and loft conversions typically proceed under permitted development or a lawful-development certificate. Inside the Church End conservation area, or near the listed buildings around St Mary's, expect a full householder application with attention to setting and skyline.

Typical Hendon housing stock

A linear historic village around the medieval St Mary's parish church, where over half the buildings are residential, set among Victorian and interwar houses that make up the wider NW4 suburb.

Streets we regularly draw for in Hendon

Church Road · Church End · Greyhound Hill · Parson Street

What NW4 is actually built of

Measured from 377 classified residential buildings in NW4, not from a description of the area.

Hendon NW4 housing mix

Residential building form across the NW4 postcode district, from 377 classified buildings.

Attached on more than one side	30%
Attached on one side	53%
Detached	18%
Median building footprint	83 m²
Addresses per buildingAbove about 2 means flats and maisonettes dominate	2.03
Buildings classified	377

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.

House Extension Drawings for Hendon (NW4) homes: the package and the process

Extension drawings are read for their dimensions. The proposed plan needs depth measured from the original rear wall — not from a previous extension — eaves and ridge heights taken from existing ground level, and the distance to each boundary marked. A site plan showing how much garden remains is what an officer reaches for when the amenity question comes up.

We draw the existing building accurately first, because everything else is measured from it. Where the original footprint has already been added to, that history goes on the drawing: it decides which allowances are still available and it is the first thing an officer checks against the council's own records.

The plot decides the extension type long before taste does. A mid-terrace has depth to work with and an alley if it is lucky; a semi has one clear flank; a detached house can go wide. Reading the building form first is what stops a design being drawn that the plot cannot take.

Which extension types do you draw?

Every London extension is shaped by the plot, the neighbours and the borough's design guidance. We draw them all.

Rear extension

A single-storey rear extension is often permitted development within depth limits — ideal for an open-plan kitchen-diner.

Side-return

Fills the alley beside a Victorian terrace, widening the ground floor without losing garden.

Wraparound

Combines a rear and side-return extension for a transformative ground floor, usually needing planning permission.

Double-storey

Adds space above and below, subject to tighter scale and neighbour-impact scrutiny.

Basement

Creates space downward where footprint is limited, with structural and party-wall care.

Do I need planning permission for a house extension in London?

Single-storey rear extensions within permitted development limits (up to 6m for terraced/semi-detached homes under the larger-home scheme, subject to neighbour consultation) may not need a full application. Wraparounds, double-storeys and anything in a conservation area usually do. We assess your plot and recommend the right route before drawing. The current depth, height and eaves limits are set out in full in the guide to planning permission for a rear extension, and where you would rather one practice ran the design, the application and the building-regulations stage together, Architectural Drawings covers that full scope.

How do you maximise the footprint the council will approve?

We know each borough's depth, height and daylight standards, so we design to the edge of what will be approved rather than guessing — and we check the 45-degree neighbour daylight rule and any rear building line before submission. Where a plot is tight we test a permitted-development scheme against a slightly larger householder application and show you the trade-off in space, cost and timescale, so the drawn scheme is the one that actually maximises value rather than just floor area.

Typical London extension drawing packages
Extension	Typical route	Package	Fee from
Single-storey rear	Permitted development / householder	Planning + building regs	£1,100
Side-return	Householder planning	Planning + building regs + structural	£1,600
Wraparound	Householder planning	Full package + structural	£2,200
Double-storey	Householder planning	Full package + structural	£2,400

Sheet from a house extension drawings package drawn for a Hendon property in NW4, showing the existing and proposed arrangement at scale — A sheet from the house extension drawings package we submit to London Borough of Barnet for Hendon (NW4) properties.

Also in Hendon NW4

Planning Permission Planning Drawings Architectural Drawings Building Regulations Drawings Loft Conversion Drawings House Extension Drawings across Barnet House Extension Drawings across London

FAQ

House Extension Drawings in Hendon NW4 — FAQs

How far can I extend without planning permission in London?+

Under permitted development, single-storey rear extensions can reach 3m (terraced/semi) or 4m (detached), or up to 6–8m under the prior-approval larger-home scheme — but conservation areas and Article 4 directions can remove these rights. We check your property first.

Do extension drawings include structural calculations?+

Our full package includes structural drawings and calculations coordinated in-house, so your builder can price and build without waiting on an engineer.

How long do extension drawings take?+

Typically about 7 days from survey to a full drawing set delivered to your online portal.

Will my rear extension need a party wall agreement?+

If you build up to or on a shared boundary, excavate near a neighbour's foundations, or cut into a party wall for a steel, the Party Wall etc. Act 1996 usually applies. Our drawings show the works clearly so a party wall surveyor — or your neighbour — can see exactly what is proposed, which keeps that process quick.

Can I extend a house in a conservation area?+

Yes, but conservation areas and Article 4 directions commonly remove permitted development for rear and side extensions, so the work needs a full householder application designed to the council's heritage guidance. We confirm your property's designation before recommending a route.

Do I need planning permission for a loft or extension in Barnet?+

Across Finchley, Edgware and Hendon, Barnet's 1930s semis usually keep permitted development rights for rear extensions and hip-to-gable or dormer lofts, so a full application isn't always needed. The major exception is Hampstead Garden Suburb, where an Article 4 direction removes almost all permitted development rights. We check your address first and confirm permitted development with a Lawful Development Certificate where it applies.

What is different about building in Hampstead Garden Suburb?+

The Suburb has one of the most far-reaching Article 4 directions in London: almost all external alterations need planning permission, and the Hampstead Garden Suburb Trust must also consent to changes in parallel with the council. We handle both tracks — a carefully evidenced planning application to Barnet and the Trust's design requirements — since approval there depends on respecting the Arts-and-Crafts character precisely.

Is a hip-to-gable loft conversion allowed on my Barnet semi?+

Usually, yes. The borough's abundant interwar semis are well suited to hip-to-gable and dormer conversions, which frequently qualify as permitted development on semi-detached homes within the volume limits. Outside conservation areas and the Suburb, this is often the quickest route. We confirm eligibility, then produce the planning and building-regulations drawings.

How long does Barnet take to decide an application?+

Barnet determines most householder applications within the statutory eight-week period once validated; Suburb and conservation cases can involve additional consultation. We prepare Barnet submissions to the validation checklist, with the elevations and materials detail the council expects, to avoid the drawing queries that are the usual cause of delay.

How much do Barnet planning drawings cost?+

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 Barnet approves. A straightforward Finchley loft and a Hampstead Garden Suburb application differ in the evidence required, so we quote once we have seen the project and know which route applies.

Free Fixed Quote

Get your free Hendon planning assessment

Tell us your Hendon (NW4) address and ambition — we'll confirm feasibility, local constraints and a fixed fee within one working day.