Well there is a solution to this. Instead of assuming the AI can figure out how to repair any arbitrary house (though it might actually be doable), if houses were factory built, the robots/AI can be much more limited.

Basically, make the whole house/office building out of flat panels and other objects designed to fit into the dimensions of a max size load truck and easy to assemble on site. Robot trucks haul the pieces to the job site, robot cranes lift them into place, robots probably ride the piece up (no OSHA standards for them!) and use their arms to pull it into alignment and bolt/weld into place.

So the solution would be to basically take a 100 year old house and replace it with a brand new house where it's been made to look externally like the same house.

The new stuff would be robot repairable, with everything behind panels that robots can easily remove and subdivided into modules that can be easily removed and replaced.