House Extension Drawings in Harlesden NW10
Fixed-fee, MCIAT-chartered house extension drawings for Harlesden (NW10) homeowners — London Borough of Brent validation and local constraints handled from the start.
Harlesden (NW10) is a dense Victorian terraced neighbourhood built around the High Street and the landmark Jubilee Clock, with a high share of houses already converted to flats. That mix means the work here spans rear and side-return extensions, loft conversions and the drawings that go with flat-conversion and change-of-use schemes.
The Harlesden conservation area covers the historic core around the High Street, so frontage changes, dormers and materials there face tighter control than on the surrounding streets. We check where a Harlesden property sits relative to that boundary, and whether it is in single-family or flatted use, before recommending a route and preparing the application to Brent's standards.
Planning in Harlesden (NW10): what to know before you apply
NW10 has no published householder Article 4 direction in Harlesden affecting typical extensions, so many terraces retain permitted development rights — but the Harlesden conservation area around the High Street is the exception, and the high level of existing flat conversions means amenity and layout are scrutinised closely.
Typical Harlesden housing stock
Dense Victorian terraces radiating from the High Street and the Jubilee Clock, a large share already converted to flats, alongside pockets of later infill — a mix that makes both extensions and conversion-related work common.
Streets we regularly draw for in Harlesden
Tubbs Road · Craven Road · Winchelsea Road · Crownhill Road
What NW10 is actually built of
Measured from 424 classified residential buildings in NW10, not from a description of the area.
Harlesden NW10 housing mix
Residential building form across the NW10 postcode district, from 424 classified buildings.
| Attached on more than one side | 63% |
|---|---|
| Attached on one side | 33% |
| Detached | 4% |
| Median building footprint | 68 m² |
| Addresses per buildingAbove about 2 means flats and maisonettes dominate | 1.8 |
| Buildings classified | 424 |
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 Harlesden (NW10) 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.
| 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 |
House Extension Drawings in Harlesden NW10 — FAQs
How far can I extend without planning permission in London?+
Do extension drawings include structural calculations?+
How long do extension drawings take?+
Will my rear extension need a party wall agreement?+
Can I extend a house in a conservation area?+
Do I need planning permission for a side-return extension in Brent?+
What does Brent's borough-wide HMO Article 4 direction affect?+
Is a hip-to-gable loft conversion allowed on my Brent semi?+
How long does Brent Council take to decide?+
How much do planning drawings cost in Brent?+
Get your free Harlesden planning assessment
Tell us your Harlesden (NW10) address and ambition — we'll confirm feasibility, local constraints and a fixed fee within one working day.