It does not include an elderly person who is not disabled or chronically sick or any person who’s only temporarily disabled or incapacitated, such as with a broken limb.
If a parent, spouse or guardian acts on behalf of a ‘chronically sick or disabled’ person, the supply is treated as being made to that ‘chronically sick or disabled’ person.

VAT exemptions for disabled people are not means-tested. They are not dependent on the benefits a disabled person may or may not receive and a person does not have to be registered disabled in
order to qualify.

Qualifying clients will need to complete a VAT Exemption certificate. You do not need your doctor or any other medical professional to do this.

For more information please visit the HMRC website and consult Reliefs from VAT for disabled and older people (Notice 701/7).

https://www.gov.uk/guidance/reliefs-from-vat-for-disabled-and-older-people-notice-7017

Disabled Facility Grants (DFG)
If you are disabled or chronically ill, then you may qualify for a Disabled Facilities Grant (DFG). The grants are provided by your local authority and are designed to assist with the cost of adapting homes.

They are usually means tested and can involve a charge being placed on the property if grants exceed a certain threshold, usually £5000. However, not all local authorities have the same criteria so it is best to speak to them directly.
For more information contact your local authority or visit
https://www.gov.uk/government/publications/disabled-facilities-grant