- Planning authority
- London Borough of Merton
- Postcodes
- CR4, SM4, SW19, SW20
- Noon sun, 21 March
- About 39°
- Shadow from a 5 m eaves line
- About 6.3 m
- Planning plan
- Local Plan
- County
- Greater London
How it plays out in Merton
The London Borough of Merton will judge a family home against the council’s Local Plan and any guidance it has adopted on garden development and annexes. Some councils spell out how closely an annexe must relate to the main house, such as sharing the drive, garden or parking, and what turns a building into a separate home instead. We read the current policies for your address before design starts, because a scheme drawn to suit the wrong test wastes time and money. Where the position is unclear, the council’s pre-application advice can be worth its fee.
How we’d take it forward in Merton
Here’s what happens next for a family home in Merton. You tell us about your plot and who the home is for, and we carry out a free desktop appraisal of access, space and the planning context. If it looks viable we visit, then set out the annexe and separate-home options. With your go-ahead we survey, design and give you a written quote, then prepare the application for the London Borough of Merton.
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.
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
- A separate home needs its own garden, parking, bins and access, so it needs more land than an annexe.
- VAT savings available on a separate dwelling often don’t apply to an annexe; take advice from a tax adviser before choosing.
- An annexe tied by planning condition usually can’t be sold or let separately, which limits flexibility later.
Questions about garden plots in Merton
Is CIL payable on a family home in Merton?
Only if the London Borough of Merton 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.
Will an annexe in Merton 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. The London Borough of Merton’s council tax team can tell you how the rules apply to your household.
Can I reclaim VAT on a family annexe in Merton?
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.
How much garden do I need for a family home in Merton?
There’s no fixed figure. A single-storey annexe close to the house can work on a smaller plot than a separate dwelling, which needs its own garden, parking and access. What matters is whether the London Borough of Merton can be satisfied on privacy, daylight and the space left for both homes. The free appraisal gives you a first view based on your plot’s actual shape and access.
Other options in Merton
- Garden plot option agreement
- Corner and side plots
- Bungalows on large plots
- Build a new home in your garden
- Garage courts and yards
- Planning permission for a garden plot

