Build a home for family in your garden in Hounslow

The first question for any family in Hounslow thinking about building in the garden is usually this: annexe or proper house? The answer turns on the person moving in, how long they’re likely to stay, and whether you might ever want to sell or let the building on its own.

An annexe is used with your home and usually tied to it by condition. A separate dwelling stands alone, with its own permission and potentially its own title. The London Borough of Hounslow assesses them on different terms, and council tax, CIL and VAT rules split along the same line. Our free plot appraisal sets out both, so you can decide with your family and your advisers.

Single-storey garden home with wide glazed doors and a covered porch at the back of a family garden
Planning authority
London Borough of Hounslow
Postcodes
TW3, TW4, TW5, TW7, TW13
Noon sun, 21 March
About 39°
Shadow from a 5 m eaves line
About 6.3 m
Planning plan
Local Plan
County
Greater London

Before you decide in Hounslow

How the two households will live together shapes the planning case as much as the drawings do. If your parent will eat with you, share the garden and rely on you day to day, an annexe is the natural fit, and that is what the London Borough of Hounslow will expect the application to describe. If your son or daughter will run their own home, pay their own bills and perhaps sell up one day, it is a separate dwelling and will be assessed against the council’s Local Plan as a new house. For a family in TW3, TW4, TW5 and TW7, we help set that out clearly from the start.

Section showing noon sun and shadows in Hounslow: about 39 degrees on 21 March and 15 degrees on 21 December21 m21 Mar, noon: sun 39°, shadow 6.3 m21 Dec, noon: sun 15°, shadow 18.5 mExistingNew home
This section is worked out for the latitude of Hounslow: around 39° of sun at midday in late March and about 15° at midwinter. It shows why the gap between your house and a new home behind it is about light as well as privacy. Garden assumed to face north.

What happens next in Hounslow

Getting started in Hounslow costs nothing. Send us a few photos of your garden and the way in, or simply call, and we’ll look at the plot from the desk and talk through your family’s plans. If there’s a realistic scheme, we arrange a site visit. Survey and design are quoted in writing before you commit, and the build price follows once the design is settled.

  1. Free plot appraisal

    We look at your plot, access and the planning picture from the desk, talk through who will live in the new home, and visit if it looks viable. There’s no cost and no obligation.

  2. Annexe or separate home

    We set out both routes for your plot, covering what each means for planning, ownership, council tax, CIL and VAT, so you can decide with your family and advisers before design starts.

  3. Survey and design

    A measured survey, then a design built around the person moving in: step-free routes, a ground-floor bedroom if needed and privacy for both households. You get a written quote after design and survey.

  4. Planning and approvals

    We prepare and submit the planning application and manage it with the council, which makes the decision. Before work starts, approval under the Building Regulations is in place and any CIL exemption has been claimed.

Worth checking early

  • An annexe tied by planning condition usually can’t be sold or let separately, which limits flexibility later.
  • Family plans change: agree ownership, costs and what happens if circumstances change in writing, with a solicitor.
  • Planning is the council’s decision, and an annexe is not a way round the rules that apply to a new house.

Hounslow: questions to ask

Can you design a home in Hounslow for a relative who uses a wheelchair?

Yes. The design can include a level approach and threshold, turning space in each room, a wet room, wider doors and worktops at a usable height. Where the London Borough of Hounslow requires a particular access standard through planning, the design meets it; otherwise it’s your choice how far to go. Input from your relative’s occupational therapist is well worth having.

Who owns an annexe built in my Hounslow garden?

You do. An annexe stays on the title of your house and usually carries a planning condition tying it to the main home, so it can’t be transferred to the relative living in it. If a family member is paying towards it, record what they’ve put in and what happens on a sale in a written agreement drawn up by a solicitor.

How long will building work disrupt my home in Hounslow?

A single garden home usually takes several months on site, with the noisiest work, such as groundworks, drainage and heavy deliveries, concentrated near the start. We agree working hours, access and parking with you up front, and with the people next door where it affects them, so your household knows what each week will look like.

Can I reclaim VAT on a family annexe in Hounslow?

Often not. HMRC’s guidance gives an annexe that can’t be used or sold separately from the main house as an example of work that can’t be zero-rated, and the DIY housebuilders refund scheme asks the same question. A separate dwelling is usually treated differently. Take advice from a tax adviser before you settle the planning route, because the wording of the permission matters.

Other options in Hounslow

Family home in your garden near Hounslow

Find out what your garden could become

Free garden plot appraisal. No cost, no obligation, and a straight answer if it won’t work.