Hi Emma,
I would check with your planning area and see what is the authorised use for this building. If the owner wants to change I would have asked him to get an approval from Planning Department for the change of use from business to residential before changing the rating category. I believe it is under S96 of the Act.
This way it gets recorded that the owner cannot use the building as a business and has to use it as a residential building. If he does then he in breach of use and compliance team can tke action against it. In the current scenario I would still charge him business rates as the building has an approved use as a massage parlour and not residence, unless stated othewise.
