Loft Conversion Drawings in Isleworth | From £1,225

No Article 4 Direction covers Hounslow, which keeps the Isleworth permitted-development route open on unlisted houses. What defines Isleworth is that it is Georgian and Victorian terraces, and design decisions here answer to that rather than to a pattern book. Inside the Old Isleworth boundary — one of 30 such designations in Hounslow — a Isleworth scheme normally goes straight to a full Hounslow Council application rather than relying on permitted development. The Isleworth boundary position decides how much can be done under permitted development.

That mapping of Article 4 directions across Isleworth happens before design, which is what keeps the Hounslow Council route predictable. On a Isleworth house the measurements bite through the georgian and victorian terraces: it sets the original rear wall, and the roofline around Old Isleworth sets what ridge height will pass. The borough policy layer over every TW7 address is set out on Hounslow planning. The Isleworth survey then carries into planning permission in Isleworth if the project runs on to construction.

London Borough of Hounslow takes one to two weeks to validate a Isleworth submission. We start with a full laser survey of the Isleworth address so the existing set is dimensionally right before anything proposed is drawn.

Statutory periods: 8 weeks from validation for a householder application, 13 weeks for a major scheme, 6 weeks for prior approval with a 21 days neighbour consultation, and 5 weeks for a full plans building control submission. A party structure notice requires one month notice and two months where excavation is involved.

Amendments during the Isleworth determination are handled without a resubmission where possible. The TW7 pack is issued at 1:100 and 1:50 with a 1:1250 location plan.

Objection volume on Isleworth cases is public — we read it before advising. We measure the TW7 property room by room, including ceiling heights and floor falls.

Serve TW7 party wall notices before work starts, not after. Once consent is granted, building regulations drawings follows for the TW7 property.

Isleworth is characterised by georgian and victorian terraces, concentrated across TW7 in the Isleworth area. The construction sequence on a Isleworth job follows the georgian and victorian terraces, not a standard detail sheet. Where Isleworth is concerned, georgian roofs here are shallow and often behind a parapet, so the usable volume comes from a rear dormer set below the ridge rather than from the front slope. That detail drives the TW7 construction sequence. A Isleworth proposal that breaks the prevailing eaves line invites a refusal.

A Isleworth basement stands on its drainage and party wall evidence. A Isleworth survey done once feeds house extension drawings for TW7 properties and architectural drawings later.

What the Isleworth drawing pack contains

Contents of the TW7 drawing pack:

• existing roof plan and section for the Isleworth property
• proposed dormer elevations
• volume calculation sheet
• staircase and head-height sections
• structural steel layout

Streets and landmarks we survey around Isleworth

• Hampton Hill — side returns where the 45-degree amenity test decides how far a Hampton Hill extension goes.
• Herne Hill — roof profiles that set the ridge datum Hounslow Council measures a Herne Hill dormer against.
• Gosford Park — terraced rear elevations — the Gosford Park party wall position is drawn first.
• Syon Park — frontages visible from the highway, so Old Isleworth materials detail governs the Syon Park elevation.
• Old Isleworth — a Isleworth roof extension is judged against the datum it sets.
• Maidenhead Bridge — it fixes the local datum a Isleworth roof extension is judged against.
• Staines Bridge — proposals within its setting are drawn with the context elevation included.
• Winchester College — proposals in its setting are drawn with the Isleworth context elevation.
• South Middlesex Hospital — Hounslow Council weighs TW7 sightlines to it in the character assessment.

Getting to a Isleworth survey

Surveyors travel to TW7 addresses from the studio; the nearest stations are Osterley, Isleworth, Weybridge, Syon Lane. Appointments are booked in Isleworth on weekdays and Saturdays, and the measured survey of a standard georgian and victorian terraces takes two to three hours.

Where Isleworth sits

on Ordnance Survey grid reference TQ1575, with the River Thames shaping drainage and flood-risk questions on lower-lying TW7 plots, inside the Brentford and Isleworth parliamentary constituency. That grid reference is not trivia — the Isleworth site location plan is drawn over it, and Hounslow Council validates the address against it. Source.

Practical detail for a Isleworth submission: local stations are Osterley and Isleworth and Weybridge and Syon Lane; TW7 addresses are written to ISLEWORTH; dialling code 020. Site plans are drawn to the address as Hounslow Council holds it.

Isleworth postcode coverage

We draw TW7 (Isleworth), which Isleworth holds on its own addresses, and Hounslow Council validates each on the address itself.

Streets and stations in Isleworth

Our TW7 caseload covers Hampton Hill, Herne Hill, Gosford Park and Syon Park. most Isleworth sites are within walking distance of Osterley or Isleworth or Weybridge.

Areas we cover around Isleworth

We survey across Barons Court (W14), Brackenbury Village (W6), Sand's End (SW6), Richmond (TW9, TW10), Twickenham (TW1, TW2), Kew (TW9) as well as Isleworth itself, plus the Richmond upon Thames side of the boundary.

The figure is agreed before the survey and does not move. The fee follows the building. On Isleworth stock that means party walls, levels, and the Old Isleworth heritage question.

Statutory application fees are set by regulation, not by the council: £548 householder, £610 for a new dwelling, £274 for a lawful development certificate, £249 for prior approval.

The statutory element is payable to London Borough of Hounslow, not to us. London planning approval-rate dataset · Hounslow planning · loft conversion drawings in London · loft conversion drawings in Barons Court.

MCIAT chartered technologists handle every TW7 submission we make. On a marginal Isleworth plot we would rather spend on Hounslow Council pre-application advice than lose 8 weeks to a refusal on a TW7 address.

Drawings are produced by chartered members of the Chartered Institute of Architectural Technologists (MCIAT), the professional body for technical design and building-regulations competence. First-time approval across our London caseload is 98%. Statutory fees shown are those in force in England in 2026 under the Town and Country Planning (Fees for Applications) Regulations. Confirm your local authority at gov.uk and submission requirements on the Planning Portal. Studio: 71–75 Shelton Street, London WC2H 9JQ.

Tell us the TW7 address and what you want to build; the rest we handle. This Isleworth page was reviewed in August 2026.