Which postcode districts around Hillingdon do we cover for conservation area application work?
UB and HA districts split the borough between two quite different planning contexts: Uxbridge and Hayes in the south, Ruislip, Eastcote and Northwood in the north, with HA5 crossing into Harrow. Each row names the dominant construction, and which council would be handling a designated-area submission from it. Application fees below are national 2026 figures and identical in every borough.
| Postcode | Area | Dominant stock | What it means for a conservation area application |
|---|
| UB9 | Denham / Harefield | Tudor and Georgian fragments, 1930s semi-detached | Conservation area work in UB9 turns on which council made the designation. Hillingdon's designations cover the Harefield side and Hillingdon holds those appraisals; the Denham side lies in Buckinghamshire, where that council keeps the appraisals and management plans and decides the application. Two registers, two sets of Article 4 directions, one postcode. |
| UB10 | Hillingdon / Ickenham | 1930s semi-detached, Tudor fragments | A conservation area application at an UB10 address in Hillingdon / Ickenham is determined by Hillingdon Council under its own Local Plan policies for Hillingdon / Ickenham. |
| UB11 | Stockley Park | Inter-war semis dominate: 29.8% of the borough's 118,250 homes were built in the 1930s alone, recorded at 31 March 2025. Victorian cottages survive at Uxbridge and in the old Ruislip village core, post-war housing runs out towards Heathrow, and Green Belt covers much of the north | UB11 covers Stockley Park only; Hillingdon Council handles the conservation area application. |
| HA4 | Ruislip | 1930s semi-detached, Tudor cottages | A conservation area application at an HA4 address in Ruislip is determined by Hillingdon Council under its own Local Plan policies for Ruislip. |
| HA5 | Pinner / Eastcote | Tudor fragments, Edwardian villas, 1930s semi-detached | HA5 is shared ground: a Pinner or Eastcote address may be validated by Hillingdon or by Harrow, and the boundary follows street lines rather than the postcode. We resolve which applies from the policies map before quoting. |
| HA6 | Northwood | 1930s detached, Edwardian villas | Northwood sits wholly inside HA6, so Hillingdon Council validates every conservation area application submitted from an HA6 address. |
| UB3 | Hayes / Harlington | 1930s semi-detached, post-war estates | UB3 lies entirely within the borough, so Hayes and Harlington addresses go to Hillingdon Council and there is no boundary to resolve beforehand. |
| UB4 | Hayes / Yeading | 1930s semi-detached, post-war estates | UB4 covers Hayes / Yeading only; Hillingdon Council handles the conservation area application. |
How does a conservation area application differ street by street across Hillingdon?
Two Ruislip houses 200 metres apart can support entirely different schemes. Roof angle, back-plot depth and what the walls are actually built of shift from street to street, and inside a designated area those three measurements decide what an officer will accept. We take them before designing, not afterwards.
- Hayes (UB3, UB4) — a conservation area application in Hayes starts from 1930s semi-detached, post-war estates, and Hayes reads as 1930s semi-detached, post-war. On these 1930s semis the prior approval route often replaces a full application in UB3. Hillingdon Council assesses Hayes conservation area applications against its own Hayes character guidance, and the location plan we draw for Hayes references Hayes & Harlington.
- West Drayton (UB7) — conservation area application work in West Drayton means 1930s semi-detached, post-war. West Drayton is 1930s semi-detached. On these 1930s semis the prior approval route often replaces a full application throughout UB7. Hillingdon Council decides the West Drayton application, and West Drayton station anchors the West Drayton location plan.
- Ickenham (UB10) — conservation area application work in Ickenham means 1930s semi-detached, tudor fragments. Ickenham is 1930s semi-detached, village conservation. On these 1930s semis the prior approval route often replaces a full application throughout UB10. Hillingdon Council decides the Ickenham application, and Ickenham Village anchors the Ickenham location plan.
- Harefield (UB9) — conservation area application work in Harefield means tudor and georgian fragments, 1930s semi-detached. Harefield is village conservation, rural fringe. Applications on Georgian stock here almost always need a heritage statement alongside the drawings throughout UB9. Hillingdon Council decides the Harefield application, and Harefield Hospital anchors the Harefield location plan.
- Yiewsley (UB7) — conservation area application work in Yiewsley means 1930s semi-detached. Yiewsley is 1930s semi-detached. On these 1930s semis the prior approval route often replaces a full application throughout UB7. Hillingdon Council decides the Yiewsley application, and Yiewsley High Street anchors the Yiewsley location plan.
- Eastcote (HA5) — conservation area application work in Eastcote means 1930s semi-detached. Eastcote is 1930s semi-detached. On these 1930s semis the prior approval route often replaces a full application throughout HA5. Hillingdon Council decides the Eastcote application, and Eastcote Tube anchors the Eastcote location plan.
- Hillingdon (UB10) — conservation area application work in Hillingdon means 1930s semi-detached. Hillingdon is 1930s semi-detached, post-war. On these 1930s semis the prior approval route often replaces a full application throughout UB10. Hillingdon Council decides the Hillingdon application, and Hillingdon Tube anchors the Hillingdon location plan.
What local planning policy applies to a conservation area application in Hillingdon?
What designation actually costs you here: the permitted development route closes. The fee for a larger householder prior approval is £249 and that decision runs to 6 weeks — but once the address is inside a boundary, the scheme becomes a full application instead. The householder application fee in England is £548, with 8 weeks to determine. Given that two decisions in five here are taken under an agreed extension, treat 8 weeks as a floor rather than a forecast. Ickenham and Ruislip Village are where we meet this most often.
Article 4 here: no borough-wide direction has been made, so an HA4 address outside a designated boundary normally retains permitted development rights in full. We record that with a Lawful Development Certificate rather than leave the point for a purchaser's conveyancer to test years afterwards. The fee for a lawful development certificate is £274.
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 conservation area application in Hillingdon is scoped against that stock first.
What happens if a Hillingdon property sits on a boundary?
- Harrow — cross the Hillingdon boundary and Harrow Council takes the conservation area application instead, applying 29 conservation areas of its own around HA1. We re-price conservation area applications at the Hillingdon edge because Harrow policy and Hillingdon policy rarely align on conservation area application depth.
- Ealing — the Ealing boundary runs against Hillingdon, so a conservation area application a street from Hillingdon is decided by Ealing Council instead. Ealing runs 30 conservation areas across W3 and its neighbours, which is why conservation area applications priced for Hillingdon are re-checked against Ealing policy whenever the Hillingdon address sits on that edge.
- Hounslow — cross the Hillingdon boundary and Hounslow Council takes the conservation area application instead, applying 30 conservation areas of its own around W3. We re-price conservation area applications at the Hillingdon edge because Hounslow policy and Hillingdon policy rarely align on conservation area application depth.
Sources for this Hillingdon conservation area application 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.
