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Free 2026 London Planning ReportHouse Extension Drawings in Isleworth TW7

Rear kitchen extension for a Victorian villa in Isleworth, Hounslow (TW7)
Isleworth · TW7 · Hounslow

House Extension Drawings in Isleworth TW7

Fixed-fee, MCIAT-chartered house extension drawings for Isleworth (TW7) homeowners — London Borough of Hounslow validation and local constraints handled from the start.

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TW7 covers Isleworth, from the Georgian riverside huddle of Old Isleworth around the church to the leafier Victorian villa streets of Spring Grove, and most homeowners here are weighing a rear or side-return kitchen extension or a loft conversion to add space without leaving a settled address.

Because the Isleworth Riverside and Spring Grove conservation areas both sit inside the outcode, the first step is a boundary check: a scheme that is permitted development on an unprotected street can need a full householder application once you are inside the conservation area, especially for anything affecting a front or riverside elevation.

Rear kitchen extension for a Victorian villa in Isleworth, Hounslow (TW7)
Isometric illustration of a Isleworth TW7 home house extension drawings design
Proposed floor plan
Isleworth TW7

Planning in Isleworth (TW7): what to know before you apply

Most rear extensions and loft conversions outside the conservation areas proceed under permitted development, subject to size and eaves limits. Inside Isleworth Riverside or Spring Grove, or on any listed building, expect a full householder application and, for listed properties, separate listed building consent.

Typical Isleworth housing stock

The Old Isleworth riverside keeps Georgian and early-Victorian terraces and cottages around the church and Church Street, while Spring Grove and the wider TW7 streets run to substantial Victorian and Edwardian semi-detached and detached villas.

Streets we regularly draw for in Isleworth

Church Street · Lower Square · Mill Plat · North Street

House Extension Drawings for Isleworth (TW7) homes: the package and the process

Every house extension drawings we prepare for an Isleworth property is drawn to London Borough of Hounslow’s validation standards and tuned to the TW7 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.

Typical London extension drawing packages
ExtensionTypical routePackageFee from
Single-storey rearPermitted development / householderPlanning + building regs£1,100
Side-returnHouseholder planningPlanning + building regs + structural£1,600
WraparoundHouseholder planningFull package + structural£2,200
Double-storeyHouseholder planningFull package + structural£2,400
FAQ

House Extension Drawings in Isleworth TW7 — 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 an extension in Hounslow?+
It depends on the area. The interwar semis of Osterley, Hounslow and Feltham often retain permitted development rights for rear extensions and lofts, while the Chiswick terraces and Bedford Park sit within conservation areas where those rights are removed. We check your address against the designations first and can confirm permitted development with a Lawful Development Certificate.
What extra control applies in Bedford Park?+
Bedford Park is one of West London's most tightly controlled conservation areas, with detailed control over materials, rooflines, windows and front elevations. A standard permitted-development dormer or cladding change usually won't apply; instead we design to the area's Arts-and-Crafts character and prepare a full householder application with the elevations and materials the council expects.
Does Heathrow or the river affect my Hounslow project?+
They can. Toward the west of the borough, aircraft-noise considerations near Heathrow may influence habitable-room and glazing design, and along the Thames at Strand-on-the-Green and Isleworth the flood zone must be addressed. We evidence these considerations within the application where they apply so the council can validate and approve without repeated revisions.
How long does Hounslow Council take to decide?+
Hounslow determines most householder applications within the statutory eight-week period once validated; Bedford Park, conservation and riverside cases can involve additional consultation. We prepare submissions to the council's validation checklist to avoid the drawing queries that cause most delays.
How much do planning drawings cost in Hounslow?+
We agree a fixed fee before starting, typically around 30% below an architect's fee for the same council-accepted drawings, with free redraws until Hounslow approves. A suburban Osterley extension and a Bedford Park application differ in the evidence required, so we quote once we understand your address and project rather than by the hour.
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