Build a home for family in your garden in Sunbury-on-Thames

If you have a long or wide garden in Sunbury-on-Thames, there may be room for a home where a parent or grown-up child can live close by with their own front door. That might mean an annexe used with your house, or a home that stands alone with permission and paperwork of its own.

Spelthorne Borough Council decides either way, so the first step is to find out what your plot can realistically carry. Our free plot appraisal covers access, space, privacy and the main planning constraints, and talks through who the home is for, before you spend any money on drawings.

Single-storey garden home with wide glazed doors and a covered porch at the back of a family garden
Planning authority
Spelthorne Borough Council
Postcodes
TW16, TW17
Noon sun, 21 March
About 39°
Shadow from a 5 m eaves line
About 6.3 m
Planning plan
Local Plan
County
Surrey

The local picture in Sunbury-on-Thames

A measured survey is where a family home in Sunbury-on-Thames stops being an idea and becomes a plan. We record boundaries, levels, trees, drains and the windows of your house and the houses next door, then test where the new building can sit. With the spring equinox sun standing near 39° at midday here, a 5 m eaves line throws a noon shadow close to 6.3 m; drawing that onto the survey shows which positions keep light in the main rooms of both homes. Spelthorne Borough Council will expect to see the same evidence with the application.

Section showing noon sun and shadows in Sunbury-on-Thames: 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 Sunbury-on-Thames: 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.

From first call to decision

Getting started in Sunbury-on-Thames 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. Build and handover

    We build while you carry on living next door, with access, deliveries and working hours agreed up front. At handover you get the completion certificate and the paperwork you’ll need for council tax, lenders and any VAT claim.

Worth checking early

  • VAT savings available on a separate dwelling often don’t apply to an annexe; take advice from a tax adviser before choosing.
  • Family plans change: agree ownership, costs and what happens if circumstances change in writing, with a solicitor.
  • A separate home needs its own garden, parking, bins and access, so it needs more land than an annexe.

Your questions, answered for Sunbury-on-Thames

Can I build a separate house in my Sunbury-on-Thames garden for my son or daughter?

Possibly, if the plot can work as a home in its own right. Spelthorne Borough Council will look at access, parking, garden space for both houses, privacy and the character of the street, as it would for any new house. If permission is granted, the plot can be transferred to your child with its own title, with your lender’s consent if the house is mortgaged.

Will an annexe in Sunbury-on-Thames put up my council tax?

It might. Annexes can be banded separately, but exemptions exist for annexes lived in by certain dependent relatives, and in some cases a discount applies where family live there or the annexe is used as part of the main home. Who qualifies depends on the relative’s circumstances and how the annexe is used. Spelthorne Borough Council’s council tax team can tell you how the rules apply to your household.

Is CIL payable on a family home in Sunbury-on-Thames?

Only if Spelthorne Borough Council has adopted the Community Infrastructure Levy, which its website will confirm, and we check it for you during the appraisal. Where it applies, self-build and residential annexe exemptions exist, but both must be claimed before work starts and can be withdrawn if the home is sold or let within three years of completion.

How long will building work disrupt my home in Sunbury-on-Thames?

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.

Other options in Sunbury-on-Thames

Family home in your garden near Sunbury-on-Thames

Find out what your garden could become

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