16 March 2021

Building a granny annexe

By Charlotte Bentley, Associate, Hayes + Storr.

If you are thinking about building an annexe for an elderly parent or other family members, you will need to have the necessary planning consents in place before starting work. If not, the local planning authority could require you to remove the dwelling and return your home to its original state. Being unable to show the requisite consents may also cause problems when you come to sell your home.

Planning permission, do you need it?

The good news is that depending on what you want to build, and where you live, you are allowed certain building works without having to make a planning application. Permitted development rights allow the improvement or extension of a home without the need to apply for planning permission, where that would be out of proportion with the impact of the works carried out.

However, a separate self-contained building in your garden is likely to need an application for full planning permission. A home extension, which satisfies other conditions relating to height and physical layout, may not.

If you’re unsure whether planning permission is required, you can apply for a certificate of lawful development. This can give you peace of mind that your proposals are lawful from a planning perspective.

What other consents will you need?

There may be restrictions in your title deeds which mean that any building works require the consent of an adjoining landowner, or another third party. If your home is a leasehold property, then it’s likely you will need consent from your landlord for any structural alterations. If your home is subject to a mortgage, you may need your lender’s consent too.

What about stamp duty land tax?

Building an annexe should not ordinarily give rise to any liability for stamp duty land tax. However, stamp duty land tax will apply on any future sale of your property, affecting how attractive your home is to would-be buyers.

What about finance and ownership?

If you are combining finances with other family members, you should all be clear about the arrangement. Ensure there is a written agreement which reflects your true intentions. This should take account of your relative contributions and what could happen in the future. For example, what legal interest, if any, will your parent have in your shared home?

Joint ownership as tenants in common may seem like the obvious and fairest choice, because it would allow each of you to have a fixed share, reflecting your different contributions. However, if your parent dies, their share in the property will pass as per instructions left in their will if they have one, or according to the rules of intestacy. You could then find yourself sharing ownership of your home with their beneficiary, which may not be what you had in mind at all.

For further information about extending your home to share with relatives, contact Hayes + Storr on 01328 863231 and ask to speak to someone in the property department.

This article is for general information only and does not constitute legal or professional advice. Please note that the law may have changed since this article was published.