House Extensions · Hounslow

House Extension Drawings in Hounslow

The whole spectrum — rear extensions, side returns, wraparounds, double-storey, basement digs. Planning-led design with detailed technical phase, ideal for edwardian villas in Chiswick and Turnham Green typical of Hounslow.

From £1,225 fixed fee 3–5 weeks to submission Covering all Hounslow postcodes
House Extensions in Hounslow — architectural technologist at work

Quick facts · House Extensions in Hounslow

Fixed fee from
£1,225 + VAT
Typical turnaround
3–5 weeks to submission
Planning authority
Hounslow Council
Conservation areas
30 in Hounslow
Article 4 Direction
No
Postcodes covered
W3 and others
Planning context

House Extensions in Hounslow — local planning context

The whole spectrum — rear extensions, side returns, wraparounds, double-storey, basement digs. Planning-led design with detailed technical phase, ideal for edwardian villas in Chiswick and Turnham Green typical of Hounslow.

Housing stock in Hounslow: Edwardian villas in Chiswick and Turnham Green; Georgian in Isleworth; 1930s semi-detached in Hounslow and Feltham; riverside new-build in Brentford.

Character: Chiswick is one of west London's most conservation-controlled areas; outer Hounslow is permissive suburban.

Population
288,000
Conservation areas
30
Planning authority
Hounslow Council
Postcodes
9 areas
What's included

Fully end-to-end in Hounslow.

Site survey & feasibility

Measured existing survey, photographic record, Article 4 and conservation check specific to Hounslow before we quote.

Design option studies

2–3 design options at concept stage — alternative layouts, glazing, roof forms.

Planning package

Site location plan, existing and proposed plans, elevations, sections, D&AS where required.

Full building regulations

Part L thermal, Part B fire, Part M accessibility, structural strategy.

Structural calculations

Steel beam, foundation, lintel design. Chartered engineer sign-off.

Party wall and Build Over

Party Wall notices where needed; Thames Water Build Over Agreement where within 3m of a public sewer.

Fixed fee — 30% below London architects

House Extensions pricing in Hounslow

Essentials

Single planning or regs submission.

from£1,225
  • Measured survey
  • Drawings & submission
  • Unlimited revisions
Start Essentials →

Bespoke

Listed, conservation, complex sites.

Custom
  • Everything in Complete
  • Heritage Statement
  • Committee representation
Discuss Bespoke →
Hounslow FAQs

House Extensions in Hounslow — your questions answered.

Direct answers to the questions Hounslow homeowners ask every week about house extension drawings.

Start a free quote →
Do I need planning permission for an extension in Hounslow?

Most standard extensions in Hounslow qualify as Permitted Development — single-storey rear up to 3m/4m, side extensions up to half the width of the house, under standard national rules. Flats, listed buildings and conservation areas need full planning permission. We confirm eligibility at the free site survey.

How big can a rear extension be in Hounslow under permitted development?

Standard permitted development allows single-storey rear extensions up to 3m (attached house) or 4m (detached) in Hounslow. Larger extensions up to 6m/8m are allowed under Prior Approval (Class AA). Flats, listed buildings and Article 4 areas in Hounslow are excluded from these PD rights.

How much does a house extension cost in Hounslow?

Our fixed-fee architectural package starts at £1,225 for a Hounslow extension (planning + building regs + structural). Typical Hounslow build costs are £2,400–£3,500 per square metre including VAT — so a 25m² side return extension is £60,000–£87,500 to construct.

Can I do a basement extension in Hounslow?

Hounslow does not have a borough-specific basement policy beyond the national framework — basement conversions are generally permissible subject to structural, drainage and flood-risk considerations. Thames Water Build Over Agreements apply where you're within 3m of a public sewer.

Do I need a side return extension or a rear extension in Hounslow?

Most Victorian terraces in Hounslow (particularly in Chiswick) benefit from both — a side return extension infills the narrow side passage to create a wider kitchen, a rear extension projects back into the garden. A wraparound combines the two. We recommend the best option at the free site visit.

Nearby boroughs

House Extensions in areas adjacent to Hounslow

We cover every London borough with the same fixed-fee approach. If your property sits on a boundary, here are the neighbouring options.

Other services in Hounslow

Need more than house extension drawings?

We cover every architectural technology service in Hounslow with one chartered team.

Planning Drawings in Hounslow

From £840. A fixed-fee, end-to-end service — measured survey, scaled drawings, Design & Access Statement where required, Planning P...

Building Regulations Drawings in Hounslow

From £840. A construction-ready drawing package compliant with every Approved Document — Part A structure, Part B fire, Part L ther...

Loft Conversions in Hounslow

From £1,225. Every loft type across every {location} roof line — dormer, mansard, hip-to-gable, L-shape, Velux. LDC or full planning ...

Mansard Roof Extensions in Hounslow

From £1,575. {location}'s most space-efficient loft solution when PD-route dormers are blocked. Our chartered team designs mansards t...

Garage Conversions in Hounslow

From £995. Turn your unused {location} garage into a bedroom, home office or open-plan kitchen-diner. Planning route assessment, fu...

Basement Conversions in Hounslow

From £1,950. Full architectural technology service for basement digs and cellar conversions in {location} — structural underpinning d...

Structural Calculations in Hounslow

From £350. Chartered structural engineer calculations for every residential intervention in {location} — steel beams, lintels, pad ...

Party Wall Services in Hounslow

From £450. End-to-end Party Wall Act 1996 service for {location} — Section 1, 3 and 6 notices, schedule of condition surveys, party...

Rear Dormer Loft Conversions in Hounslow

From £1,225. London's most popular loft type — the full-width rear dormer. Planning or Permitted Development route assessed for your ...

Start your Hounslow house extension drawings application this week.

Free quote in 60 seconds. Fixed fee from £1,225. MCIAT chartered.

Get my free quote →
Free quote in 60 seconds — From £840 fixed fee Get my free quote →

Before you go…

Get a free, no-obligation quote for your project. Fixed fees from £840. MCIAT chartered.

98% first-time approval rate · All 33 London boroughs