I'm renovating 23 units this fall. What type of paint could I use to cover old oil paint? I wanted to use one type throughout to save time and money.

First, wash the walls thoroughly with TSP (tri sodium phosphate). Rinse well, and then cover with an oil primer. Then, paint with a latex that has some sheen to it. Although paints are continually improving, I still go by the old adage, the more sheen, the more durability. Since this is a rental property, use an eggshell paint on the walls, a semi-gloss in the kitchen and bathroom, and a high gloss on the trim. It will save you money in the long run.