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Free 2026 London Planning ReportWraparound Extension Drawings in Isleworth TW7

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

Wraparound Extension Drawings in Isleworth TW7

Fixed-fee, MCIAT-chartered wraparound 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 wraparound 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

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

Every wraparound 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 wraparound extension is what happens when a rear extension and a side return are designed together rather than as two separate projects: the new build wraps around the back corner of the house, turning a galley kitchen and a small rear room into one continuous kitchen, dining and living space running the full width of the plot. It is the most ambitious single-storey option most London terraces and semi-detached houses have, and because it reshapes almost the entire ground floor, it needs careful structural and drainage planning as well as a confident planning application.

DrawingsDirect draws wraparound extensions for full planning and building regulations, with structural calculations for the L-shaped frame and any drainage diversion produced in-house by our MCIAT-chartered team, on a fixed fee. If your project is a single-storey rear addition or a side infill on its own, see our Rear Extension and Side Return Extension pages; if you also want a second storey, see Double Storey Extension Drawings.

What makes a wraparound extension different from a rear or side return alone?

A rear extension adds depth at the back of the house; a side return adds width down the alley; a wraparound does both at once, so the new floor area turns the corner of the original building rather than sitting against just one wall. The result is typically the largest open-plan space a single-storey extension can deliver, but it also means more of the original external wall is removed and more of the roof is new, which raises the structural and drainage stakes compared with either extension on its own. Homeowners who start out planning a rear extension or a side return alone often move to a wraparound once they see how little extra it costs to combine the two, since much of the groundwork, roof structure and glazing is shared between them rather than duplicated.

Do wraparound extensions need full planning permission in London?

Almost always, yes. Permitted development allowances are calculated on combined additions to the original house, and a wraparound's depth plus width together generally exceed the volume and footprint limits that apply to a rear extension or side extension considered separately. A Lawful Development Certificate route is rarely viable for a genuine wraparound.

Conservation area status and Article 4 directions, common across the terraced streets where wraparound extensions are most popular, remove permitted development rights further still, so we design every wraparound on the assumption it will go through full householder planning.

Wraparound extension planning routes
RouteWhat it coversTypical fee
Full planning permissionRequired for almost all wraparound extensions given the combined footprintFull Planning pack ~£1,600–£2,400
Planning + Building Regulations (structural)Combined pack including structural calculations for the L-shaped frame and drainage diversionPlanning + Building Regs pack ~£2,200–£3,850
Rear extension alone (comparison)Smaller single-storey addition, may qualify for permitted developmentsee Rear Extension Drawings, from £1,100
Side return alone (comparison)Widens the kitchen only, keeps garden depth unchangedsee Side Return Extension Drawings, from £1,400
FAQ

Wraparound Extension Drawings in Isleworth TW7 — FAQs

How much does a wraparound extension cost to design in London?+
Wraparound extension drawings start from £2,200, covering full planning permission and structural design for the combined frame. Adding building regulations and construction detail brings the package to the Planning + Building Regs band, up to around £3,850, fixed and agreed upfront.
Does a wraparound extension always need planning permission?+
In almost every case, yes. The combined depth and width of a rear and side return together generally exceed permitted development limits, so we design wraparound projects on the assumption a full householder planning application is needed.
Do I need an architect for a wraparound extension?+
No. DrawingsDirect is an MCIAT-chartered architectural technologist practice, producing the same council-accepted drawings and structural coordination as an architect, for a fixed fee typically around 30% lower, with one team responsible for both the rear and side return elements rather than two separately briefed designers.
Will I need a Party Wall Agreement for a wraparound extension?+
Usually, because the side return element of a wraparound typically builds against or close to the boundary with the neighbouring property. We prepare the drawings your Party Wall surveyor needs alongside the planning application, timed so the notice period runs in parallel with the council's determination rather than adding to your overall timescale.
How long does it take to get wraparound extension drawings?+
Drawings are typically ready around 7 days from survey. A householder planning application then has a statutory 8-week determination period once submitted.
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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