Attaching concrete walkway to foundation with rebar

I have gotten quotes for walkways down the sides of our 2 year old home from a couple of contractors. Both have suggested drilling rebar into my poured foundation to prevent the walkways from settling in the future if there is settling in the ground underneath the walkways. Is this a common practice and is it advisable? My foundation has several cracks in it already that have had to be injected by the builder. I am worried that drilling into the foundation might produce new cracks.