This is for a sign as requested, but the usual way to say this (sign) is only
Καλώς ορίσατε=welcome (plural/polite)
to add the following is mainly used for a proper home. Nevertheless it is not wrong to use all of it.
σπίτι σας=to your home (plural/polite)

Καλώς ήλθατε στην πατρίδα! = kalos ilthate stin patrida = Welcome to your native country (or birthplace)