I'm having my concrete guy make a pad today for the new Trane XL20i condenser (37.25" x 34.25"). I told him to make it 38" x 35" - I want it to be as small as possible so people don't trip over the edges, it's right near the walkway. Is it OK to make the pad with less than an inch of extra margin? Or do I need to tell him to make it bigger (for anchoring or building code reasons)?
p.s. if I ever get a different condenser in the future that is larger, then I would just have the pad demolished and re-built. Also I don't like plastic pads, I have a psychological issue against plastic used for structural building materials since I've never seen plastic last for any length of time in my 1949 house.