How do I find out whether an engineer will need to come into my home?

[#1]

I have just moved house and signed up for plusnet, and I've been given an activation date of 18th february. All the information about the engineer appointment just says that they may need to come inside - how do I find out whether or not that's the case for this specific appointment?

[#2]

Does the property have a BT socket installed? If so, unless there are unforseen problems, it is highly unlikely anyone will need access.