Almost half of homeowners go over budget when doing a remodel, according to a report from home improvement site Houzz. A more alarming stat: Only one in five comes in under budget. When Kelly Whalen demolished her built-in bookshelves as part of a living room DIY, she found it gave the room some much-needed space. Unfortunately, she also found a hidden subfloor made from asbestos(!) tiles. She hadn’t budgeted for a new subfloor — or for the removal of a toxic substance. Yikes.