The property I own I've had quotes around $20k to install underfloor insulation due to the difficulties of access to the underfloor space. You can technically do it but would need to cut through the foundation wall and dig access trenches etc in tighter spaces.
If I was forced to do that ... I would simply add the depreciation (applicable IRD rate) and 'cost of money' onto the rent.
I insulated the walls and ceilings well when I lived there myself. But I'm guessing the ceiling won't count as I didn't get a code of compliance cert.



