Building work in Hillingdon: area guide

Hillingdon Council is the planning and building control authority for Hillingdon, which covers UB8, UB3, UB4, UB7, UB10, HA4 and HA6 and takes in Uxbridge, Hayes and Ruislip. This is our area guide to building work in the borough; for whole-house refurbishment go to Home renovation in Hillingdon.

Around 118,240 homes make up Hillingdon on the valuation list; 34% are flats and 66% houses, and 4% date from before 1919, 37% from between the wars and 59% from after 1945. VOA Council Tax stock of properties, March 2025, for all 32 statistical areas in Hillingdon. Counts rounded by the VOA.

Planning and building control in Hillingdon

What Hillingdon Council publishes about building work in the borough, with each point linked to the council page it comes from:

• There are 31 designated conservation areas in Hillingdon. pre.hillingdon.gov.uk
• Hillingdon's Article 4 Direction removes permitted development rights for residential extensions that extend beyond the rear wall of the original dwelling by more than 4 metres. pre.hillingdon.gov.uk
• Hillingdon's large rear extensions Article 4 Direction applies to the whole borough and came into force on 22 September 2014. pre.hillingdon.gov.uk
• Hillingdon says it is a criminal offence to carry out works to a listed building without first obtaining consent from the council. pre.hillingdon.gov.uk
• Hillingdon's pre-application fee for Category F, small scale minor proposals including complex or large scale extension proposals, is £504 including VAT. pre.hillingdon.gov.uk
• Hillingdon Council does not issue plans approval on a building notice and strongly recommends the route only where the builder can successfully complete the works. pre.hillingdon.gov.uk
• Under a Hillingdon building notice, work can start subject to giving 48 hours notice. pre.hillingdon.gov.uk
• Within 5 days of completing the works, Hillingdon requires a Notice of Completion on the LABC Regulation 16(4A) Completion Notice form. pre.hillingdon.gov.uk

66% of Hillingdon's homes are houses, which keep householder permitted development: a single-storey rear extension within the size limits can usually go ahead without an application, in a conservation area too unless an Article 4 direction removes it. The 34% that are flats have no householder permitted development, so their extensions and most external changes need planning permission from Hillingdon Council. Taking out a wall or a chimney breast is building regulations work, not planning, unless the building is listed.

Hillingdon is the second largest London borough and one of the most mixed in construction terms. Ruislip and Northwood in HA4 and HA6 hold interwar semis and older cottages, while Uxbridge, Hayes and West Drayton across UB3, UB7, UB8 and UB10 combine 1930s housing with substantial postwar and modern estates. That last group is underestimated: a house built in the last forty years often cannot be opened up the same way, so its construction is identified before steel is priced.

Timber frame construction on Hillingdon estates changes the steel

A large share of the newer housing here is timber frame with a brick outer leaf. From outside it looks like any other brick house. Inside, the structure is the timber panel, the brickwork is cladding, and the breather membrane and cavity do a specific job. Cutting an opening or fixing a steel into that system is a different RSJ installation from one in solid masonry.

It needs a structural engineer who has identified the construction correctly, and the vapour control layer and membranes reinstated properly afterwards, whether the job is load-bearing wall removal or an open-plan layout. We establish the construction before pricing, because guessing leads to condensation that surfaces a year later. Newer properties may still carry a structural warranty worth checking first, since altering the frame without the right approvals can affect it.

Popular starting points in Hillingdon: kitchen renovation in Hillingdon, house extensions across Hillingdon, builders in London and Staircase Renovation Cost.