The floor is currently uneven as it has some of the old floor tiles missing, so would need to be levelled(cemented?) first. There are two curved areas to cut - one round the shower tray and another around the toilet (which can't be taken out) but the total area is very small. The boxing in is just to hide pipes behind the toilet and along one wall to the basin.
I am so happy to have discovered Clive and his team. They are polite, friendly, tidy and very professional. We will definitely be using them for more work in the future!