Representatives of a company called "RCS" or something similar have recently been cold-calling on residents in Keyworth, offering to carry out surveys of their homes. It is not clear what these surveys are about, but it appears that they might be concerned with detecting a need for house repairs, e.g. missing roof tiles.
I know nothing about RCS, and they are not recommended by Rushcliffe Borough Council.
My advice about any unexpected cold-callers at the door is to give them a very quick and polite "goodbye" and immediately shut the door.
Do not let them over your threshold, as they may then be more difficult to remove.
Do not accept any visits from salespeople unless you have previously made contact with them, e.g. by phone, and arranged an appointment.
If you have a door-chain, attach it. If you don't have a door-chain, buy one.