Think you know down to the penny what your remodeling project will cost? Not so fast. You may be able to recite the price of materials and the budget for labor in your sleep, but you’re bound to get tripped up by odds, ends and extras — known in the trade as soft costs — that you never imagined shelling out for. That’s why it’s always a good idea to budget 20 to 30 percent over your remodeling estimate so that you’re covered no matter what happens. Here’s just a sampling of the surprises you might encounter. What costs have caught you off guard? Let us know in the Comments section below.