New construction is pretty straightforward, Showalter says. The GC reviews the plans and talks to all the involved parties (architects and designers, usually) to determine the project’s scope. But for renovation projects, hire the contractor who walks his subs through your home, Showalter says. If they do that, they’re serious about presenting an accurate bid that takes into account where your sewer runs, if there are any quirks that don’t show up on the plans, etc. Once the bid is in, you’re looking for transparency about how the contractor makes a profit. Charging a percentage of the total cost or a supervision fee are both common, but make sure you know which one your contractor uses and at what amounts. Showalter also suggests asking if you can see the bids by all the sub-contractors so you can tell if a GC comes back with a low profit percentage (say, 10 percent) to get the job, but is padding the sub bids for additional profit.