Usually, if the scope is settled quickly. A typical system is a one-day install, and Ohio lets the post-mitigation test start 24 hours after the fan runs, with a 48-hour minimum for a sale. The tight parts are the scoping visit and the signed paperwork.
More detail
Work backward from the closing date. The post-mitigation result has to come from the specialist who installed the system or from an independent Ohio-licensed tester, and a sale test must run at least 48 hours with either two side-by-side devices or a continuous monitor recording 48 straight hours. Before any of that, Ohio requires a visual inspection and floor plan ahead of the written proposal, and a signed proposal before any work begins. That is why the first call matters more than anything else. Share the contract deadlines, the foundation type, and whether the house has a sump or crawl space, and the scope can be built around the calendar. The real estate radon service page covers how buyers and sellers usually split the work.