Designing a granny annexe for a parent who will need care

When you plan an annexe you may be picturing a parent who still walks to the house for supper and takes a bath. The annexe also has to work for the same person after a fall, a stroke or a few years of dementia, which can mean a wheelchair, a hospital bed, a hoist and carers coming in each day. If you plan for that too, your parent is more likely to be able to stay.

If you are still deciding whether to build, the granny annexes guide sets out the options, and how much it costs to build a granny annexe covers the build itself, including one with its own bathroom and kitchen. For how the care works once your parent has moved in, read care in a granny annexe.

Before the plans are final, ask the council for a care needs assessment for your parent, and ask for an occupational therapist to be involved. An occupational therapist looks at how your parent moves, washes and gets in and out of bed, and can tell you what equipment they are likely to need and how much room it takes. The assessment is free, and the council's care needs assessment explains how to ask for one. It is also the first step towards a grant for the adaptations, which is covered further down.

The measurements come from Approved Document M, the government's guidance on the access part of the Building Regulations in England. Its strictest standard, M4(3), is for a home a wheelchair user can live in. Using it as your target gives a builder figures to price against, and the annexe will still work if your parent comes to use a wheelchair. You can read Approved Document M on gov.uk; volume 1 covers homes.

Items with no official figure, such as sockets by the bed and a key safe, come from what a carer needs to do the job. A key safe for carers lets a visiting carer or an ambulance crew let themselves in if your parent cannot get to the door, and home adaptations that reduce the need for care covers smaller changes that help too.

The difference that matters most for care is the space around the bed. A hospital bed, also called a profiling bed, raises, lowers and tilts so a carer can help your parent sit up and get out of bed. Carers work from both sides of it, and a mobile hoist has to come alongside and turn. A 750mm gap is enough for somebody walking, but not for two carers and a hoist, which is why M4(3) asks for a metre.

The second difference is the ceiling. Under M4(3), the ceilings of bedrooms and bathrooms are built strong enough for an overhead hoist carrying 200kg. A ceiling track hoist lifts your parent along a rail from bed to chair or shower, and takes up no floor space. If the joists are strengthened during the build, the track can go up later without rebuilding the ceiling. Transfers, hoists and when a visit needs two carers explains how hoists are used and who pays for them.

The bathroom is the third. A wet room has a floor that slopes to a drain with no lip to step over, and in a new annexe the fall and the drain can be laid from the start. Walk-in showers and wet rooms compares the options.

A second bedroom is the most useful single thing you can add for care. A one-bedroom annexe works for visits, but a live-in carer would have to sleep in the main house, leaving nobody in the annexe overnight. Where do live-in carers sleep? sets out what the room needs, and a live-in carer in a granny annexe covers the set-ups families use.

For the alarm, test whatever you choose from your own bed in the main house, with the doors and windows shut, before your parent moves in. A signal that carries across the garden by day may not wake you at night. Pendant alarms and sensors explains how pendants, fall detectors and door sensors work. Run a phone line or broadband into the annexe as part of the build, rather than relying on the house's wifi reaching it, so the alarm still works when your parent is in the bathroom at the far end.

When you plan who will help once your parent moves in, look before the build is finished so care can start on the day they arrive. You can search for carers near you and compare their rates by the postcode of the house. On PrimeCarers, visiting carers charge £18 to £25 an hour and live-in carers £1,050 to £1,400 a week, with our fee included. Carers are self-employed, and PrimeCarers is an introductory service: you choose the carer and agree the arrangement with them. Before a carer appears on PrimeCarers we check their ID and right to work, they hold an enhanced DBS check (or PVG in Scotland, Access NI in Northern Ireland) issued within the last 2 years, and they have passed an online interview. We do not check qualifications, training or references. References and reviews appear on profiles unverified, so ask the carer about their experience with hoists or hospital beds yourself. For visits booked through PrimeCarers, we arrange insurance cover where the carer does not have their own, subject to the policy terms.

The grant is worth up to £30,000 in England. For an adult it is means-tested on your parent's income and savings, and their partner's, with savings over £6,000 counted; your own money is not part of the test. The application is made by the owner or tenant of the home where the disabled person lives or is going to live, so if the annexe is on your property, you apply for your parent. Your parent must intend to live there for the grant period, usually five years. The Disabled Facilities Grant guide covers the means test, who is exempt from it and how long each stage should take.

What it can pay for is work your parent needs because of a disability, which the council agrees is necessary and practical. In an annexe that can include a level-access shower or wet room, a ramp, wider doors, a ceiling track hoist and heating controls your parent can use. What it does not pay for is the annexe itself, or extra space and fittings that are not about the disability. Where there is a cheaper way to meet the need, the council can limit the grant to that. The government's guidance says that where the need is somewhere to sleep, a stairlift or an existing ground-floor room is likely to be preferred over building a new bedroom.

Under the government's delivery guidance, a council with a published housing assistance policy can also fund adaptations designed into a new home, and top up a grant above the £30,000 limit. That is a local decision, so ask while the annexe is still on paper.

1. 1

   Ask for an occupational therapy assessment

   Before the plans are final

   Ring adult social care at the council where your parent will live. The occupational therapist sets out what your parent needs, which is what the grant is based on.
2. 2

   Ask the housing team about the grant

   While the annexe is on paper

   Ask whether the council will consider a grant for the adaptations in a new annexe, and whether its housing assistance policy covers a new build. Get the answer in writing.
3. 3

   Do not start the adapted work before approval

   Before anything is ordered

   The council cannot usually approve a grant for work that has already started. Wait for the approval letter before any work, deposit or order for the parts the grant is paying for.
4. 4

   Give the builder a VAT declaration

   For qualifying work

   HMRC lets some building work for a disabled person in their own home be done without VAT. Your parent, or somebody for them, signs an eligibility declaration for the builder.

Equipment such as a hospital bed, a mobile hoist or a shower chair is usually lent by the council's community equipment service after the occupational therapy assessment, rather than paid for by the grant. Check too whether it is subject to council tax, as an annexe lived in by a dependent relative can be exempt.