Loft Conversion Drawings in Hillingdon

Which Hillingdon postcodes does this loft conversion service cover?

Every Hillingdon postcode district we draw in, the stock that dominates it and the authority that validates a loft conversion there. Hillingdon fees below are the statutory England rates for 2026, not loft conversion estimates.

What changes about a loft conversion in each part of Hillingdon?

Roof pitch, wall build-up and plot depth change every few Hillingdon streets, and each one changes what a loft conversion can achieve at that address.

• Hayes (UB3, UB4) — loft conversion work in Hayes means 1930s semi-detached, post-war estates. Hayes is 1930s semi-detached, post-war. The 1930s hipped roof here needs a hip-to-gable before a rear dormer works throughout UB3. Hillingdon Council decides the Hayes application, and Hayes & Harlington anchors the Hayes location plan.
• West Drayton (UB7) — 1930s semi-detached defines West Drayton, where 1930s semi-detached, post-war set what a loft conversion can do. The 1930s hipped roof here needs a hip-to-gable before a rear dormer works across UB7. Any West Drayton loft conversion is validated by Hillingdon Council, with West Drayton station the usual West Drayton reference point on the site plan.
• Ickenham (UB10) — a loft conversion in Ickenham starts from 1930s semi-detached, tudor fragments, and Ickenham reads as 1930s semi-detached, village conservation. The 1930s hipped roof here needs a hip-to-gable before a rear dormer works in UB10. Hillingdon Council assesses Ickenham loft conversions against its own Ickenham character guidance, and the location plan we draw for Ickenham references Ickenham Village.
• Harefield (UB9) — a loft conversion in Harefield starts from tudor and georgian fragments, 1930s semi-detached, and Harefield reads as village conservation, rural fringe. Georgian roofs here are shallow and often behind a parapet in UB9. Hillingdon Council assesses Harefield loft conversions against its own Harefield character guidance, and the location plan we draw for Harefield references Harefield Hospital.
• Yiewsley (UB7) — loft conversion work in Yiewsley means 1930s semi-detached. Yiewsley is 1930s semi-detached. The 1930s hipped roof here needs a hip-to-gable before a rear dormer works throughout UB7. Hillingdon Council decides the Yiewsley application, and Yiewsley High Street anchors the Yiewsley location plan.
• Eastcote (HA5) — 1930s semi-detached defines Eastcote, where 1930s semi-detached set what a loft conversion can do. The 1930s hipped roof here needs a hip-to-gable before a rear dormer works across HA5. Any Eastcote loft conversion is validated by Hillingdon Council, with Eastcote Tube the usual Eastcote reference point on the site plan.
• Hillingdon (UB10) — a loft conversion in Hillingdon starts from 1930s semi-detached, and Hillingdon reads as 1930s semi-detached, post-war. The 1930s hipped roof here needs a hip-to-gable before a rear dormer works in UB10. Hillingdon Council assesses Hillingdon loft conversions against its own Hillingdon character guidance, and the location plan we draw for Hillingdon references Hillingdon Tube.

Does Hillingdon planning policy restrict a loft conversion?

Hillingdon conservation designations: there are 29 across Hillingdon Council, Uxbridge, Ruislip Village, Northwood among them. Designation costs a Hillingdon owner the permitted-development route: a loft conversion then needs a £548 householder application over 8 weeks, in place of the £249 prior approval route that takes 6 weeks. Northwood is the Hillingdon designation that most often changes a loft conversion design.

Hillingdon permitted development status: there is no borough-wide direction from Hillingdon Council, so a loft conversion at a HA4 address is normally still permitted development. We certify that with a £274 Lawful Development Certificate rather than leaving a Hillingdon sale to argue it later.

The building fabric around Hillingdon: 1930s semi-detached dominates; Metropolitan Green Belt covers much of north Hillingdon; Victorian cottages in Uxbridge and Ruislip villages; post-war housing near Heathrow. Largest outer west London borough; significant Green Belt; Heathrow noise contours affect planning decisions in Harmondsworth and Sipson. A loft conversion in Hillingdon is scoped against that stock first, because it decides whether the scheme runs as permitted development, a £274 Lawful Development Certificate, or a full £548 application to Hillingdon Council.

What happens if a Hillingdon property sits on a boundary?

• Harrow — cross the Hillingdon boundary and Harrow Council takes the loft conversion instead, applying 29 conservation areas of its own around HA1. We re-price loft conversions at the Hillingdon edge because Harrow policy and Hillingdon policy rarely align on loft conversion depth.
• Ealing — cross the Hillingdon boundary and Ealing Council takes the loft conversion instead, applying 30 conservation areas of its own around W3. We re-price loft conversions at the Hillingdon edge because Ealing policy and Hillingdon policy rarely align on loft conversion depth.
• Hounslow — the Hounslow boundary runs against Hillingdon, so a loft conversion a street from Hillingdon is decided by Hounslow Council instead. Hounslow runs 30 conservation areas across W3 and its neighbours, which is why loft conversions priced for Hillingdon are re-checked against Hounslow policy whenever the Hillingdon address sits on that edge.

Sources for this Hillingdon loft conversion page: borough policies maps and conservation-area registers (2025–26), Royal Mail postcode district boundaries, the Town and Country Planning (Fees for Applications) (England) Regulations, the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended, and the Party Wall etc. Act 1996.