For the rent a room tax relief, I know the room/area being rented has to be connected to the house - so for example granny flats and converted garages (attached to house) can qualify for the 14k per year tax relief.

If I was to add an extension to the back of my house in way of a studio/modular home where it would be connected to the house (but with 1 door into the extension and another into the house), would this qualify for the tax relief?

Or would I need to have a single door at the back of the house, which leads to a hallway with a door to each of the house and extension to qualify for the tax relief?

Would having a small kitchen/bathroom in the studio/modular home affect this?