A doorbell?

Give him the button, wire the bell to an outlet in your suite, and run two-conductor wire from his button to the bell.

If you already have a doorbell, even better -- use it, and still run two-conductor wire from it down to a button for him.

EDIT: or forgo the wire, and purchase a "wireless" doorbell system. Except it probably won't work with all of that concrete and rebar. So you pretty much will have to run a wire.