Building work in Hounslow: area guide

Hounslow Council is the planning and building control authority for Hounslow, which covers TW3, TW4, TW5, TW7, TW8, TW13, TW14 and W4 and takes in Chiswick, Brentford and Isleworth. This is our area guide to building work in the borough; for whole-house refurbishment go to Home renovation in Hounslow.

Around 111,270 homes make up Hounslow on the valuation list; 50% are flats and 50% houses, and 16% date from before 1919, 28% from between the wars and 55% from after 1945. VOA Council Tax stock of properties, March 2025, for all 29 statistical areas in Hounslow. Counts rounded by the VOA.

Planning and building control in Hounslow

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

• Hounslow Council states that there are currently 29 conservation areas in the borough. hounslow.gov.uk
• Hounslow's borough-wide Article 4 Direction removing the right to change a dwellinghouse to a small HMO was confirmed on 8 August 2023 and came into force on 4 September 2023. hounslow.gov.uk
• Hounslow Council has made Article 4 directions covering all properties in the Bedford Park and Gunnersbury Park conservation areas. hounslow.gov.uk
• Hounslow's current fee schedule for householder pre-application advice on extensions, outbuildings or walls with a written response only and no meeting is £408.44. hounslow.gov.uk
• Hounslow's building control service says a full plans application is usually used for major projects such as new buildings, extensions or alterations, or a change of building use. hounslow.gov.uk
• Hounslow says a building notice is usually used for smaller projects, including chimney breast removal, installing a new bathroom, converting a garage to a room and forming a through lounge. hounslow.gov.uk
• After a Hounslow building notice is given, the council may ask for more information later and work can start 48 hours after giving notice. hounslow.gov.uk
• Hounslow's residential extension guidelines say a basement should be no deeper than a single subterranean floor. hounslow.gov.uk

With 50% of Hounslow's homes flats, the lease comes first on many jobs. Flats have no householder permitted development, so an extension or most external changes to a flat need planning permission from Hounslow Council as well as the freeholder's consent. The 50% that are houses keep the householder rights within the size limits, and in a conservation area a single-storey rear extension survives unless an Article 4 direction removes it. Check Hounslow Council's conservation area and Article 4 lists for the street before anything is drawn. Taking out a wall or a chimney breast is building regulations work, not planning, unless the building is listed.

The borough runs west from Chiswick in W4 along the Thames through Brentford and Isleworth, then inland to Hounslow itself, Heston and Feltham. The eastern end is high-value Victorian and Edwardian terraces in tightly controlled streets, where a rear opening is RSJ installation first. The western end is interwar and postwar housing on larger plots with room for house extensions. Everywhere, aircraft noise from the Heathrow approach sets glazing and roof specification.

Chiswick and Brentford terraces start at the rear wall and the party wall

The Victorian and Edwardian terraces at the eastern end of the borough are solid brick, two rooms deep, with a closet wing and a narrow side return. The usual brief is to take out the wall between the back rooms, fill the side return and open the rear to the garden. The wall between the rooms carries the floor above, so that is load-bearing wall removal, and the rear opening is RSJ installation, both designed by a structural engineer we appoint and built exactly to the drawing.

Most of these houses share a wall on both sides, so a beam bearing into it, a chimney breast cut out of a shared stack or a foundation dug close to next door is notifiable under the Party Wall etc. Act 1996. You serve the notice as building owner, or your surveyor does; we supply the drawings and programme it needs and build to any award. Many of the older streets also sit in Hounslow Council conservation areas, so the outside of any extension is checked against the designation before it is drawn.

Post-war houses and flats in the west: cavity walls, leases and noise

More than half of Hounslow's homes were built after 1945, and about half are flats. Out through Hounslow, Heston and Feltham the houses are mostly interwar and post-war semis and terraces with cavity walls, and many post-war ones have concrete ground floors, so an opening needs the cavity closed and both leaves supported rather than the detail used in a Victorian terrace. In a flat, the freeholder's licence and the shared stack come before any layout is drawn, and permitted development does not apply.

Aircraft noise is the local factor that changes the specification. Under the Heathrow approach, replacement glazing, roof insulation and ventilation are chosen together, because a quiet window is wasted if the only way to air a bedroom is to open it. We agree that specification before windows or a roof covering are ordered, and notify building control where the work is controlled.

Popular starting points in Hounslow: kitchen renovation in Hounslow, house extensions across Hounslow, builders in London and Renovation Mistakes to Avoid.