
House Extension Drawings in North Harrow and Rayners Lane HA2
Fixed-fee, MCIAT-chartered house extension drawings for North Harrow and Rayners Lane (HA2) homeowners — London Borough of Harrow validation and local constraints handled from the start.
HA2 covers North Harrow, Rayners Lane, West Harrow and Roxeth — largely a Metro-land suburb of 1920s and 1930s semis where rear extensions, loft conversions and side infills are the everyday projects. The uniform inter-war house type means Harrow's design expectations for extensions are well understood across most of the district.
Two genuine conservation areas sit inside HA2: Roxeth Hill (designated 1969), a historic village pocket at the foot of Harrow Hill, and Rayners Lane (designated 2002), which protects the Charles Holden station and the Art Deco parades on Alexandra Avenue. We confirm which side of those boundaries a property falls on before advising.


Planning in North Harrow and Rayners Lane (HA2): what to know before you apply
Most inter-war semis in HA2 retain permitted-development rights for rear and loft work, so many projects avoid a full application. The exceptions are the Roxeth Hill and Rayners Lane conservation areas, where roofline, front-elevation and material changes face tighter control and a householder application is usually needed.
Typical North Harrow and Rayners Lane housing stock
Mostly 1920s-30s Metro-land semis and terraces around North Harrow and Rayners Lane, with an older, tighter grain of historic buildings surviving on Roxeth Hill at the foot of the hill.
Streets we regularly draw for in North Harrow and Rayners Lane
Roxeth Hill · West Hill · Alexandra Avenue · Rayners Lane · Imperial Drive
House Extension Drawings for North Harrow and Rayners Lane (HA2) homes: the package and the process
Every house extension drawings we prepare for an North Harrow and Rayners Lane property is drawn to London Borough of Harrow’s validation standards and tuned to the HA2 constraints above. Here is what the drawing package covers and how the process runs from first survey to approval.
A well-drawn extension adds space and value while sailing through the council; a poorly-drawn one triggers objections and refusals. DrawingsDirect draws rear, side-return, wraparound, double-storey and basement extensions for London homes — sized to your borough's tolerances, with daylight and neighbour impact considered before the planners raise them.
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.
| 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 North Harrow and Rayners Lane HA2 — 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 loft conversion in Harrow?+
What does Harrow expect for a rear extension on a 1930s semi?+
Can I extend a home in Harrow on the Hill or Pinner?+
How long does Harrow Council take to decide?+
How much do planning drawings cost in Harrow?+
Get your free North Harrow and Rayners Lane planning assessment
Tell us your North Harrow and Rayners Lane (HA2) address and ambition — we'll confirm feasibility, local constraints and a fixed fee within one working day.