There’s a big difference between renovating a home and updating it. The former involves a more dramatic execution -knocking down walls or retiling an entire bathroom. Updating is making cosmetic changes such as painting a kitchen or replacing a light fixture. Renovating is, obviously, much more expensive and time-consuming than updating, and that’s why many sellers resist it when they’re listing their home. But before making any major renovations, ask your real-estate pro if the money you plan to spend can be recouped in the selling price.