Examples
A disabled tenant who has mobility problems asks her landlord to consent to the installation of a walk-in shower and a grab rail to help her use the lavatory. Her landlord refuses consent. It would be for the landlord to give reasons for the refusal, and to show that it was not unreasonable.
The landlord consents to the fitting of the grab rail and shower, on condition that their colour matches the other bathroom fittings, and that they must be removed if the disabled person moves out of the property. These might be reasonable conditions, but it is for the landlord to show that they are.