- 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.
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.
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.
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.
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.
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
- Large rear gardens
- Joint venture on your garden plot
- Bungalows on large plots
- Planning promotion for your garden plot
- Sell part of your garden
- Garage courts and yards

