We had the same problem and this is what we did. My husband took some leftover materials from our last renovation and framed a large part of the basement in, and then put half walls of drywall up, also used from leftovers. We used leftover carpet from all over the house and put foam mats down anywhere there wasn't carpet. I put artwork up with tape to cover the insulation and none of the other insulation is accessible to the kids because of the half walls. My husband left a doorway opening to to the half open room that was big enough to put a child gate which blocked it off from the laundry/utility area. When I interview, I tell clients that we have just moved here and are in the process of completing many projects. However, due to the weather (it is FREEZING here in the winter), we thought it prudent to create a gross motor area in the downstairs, and this is what it looks like. That way you are acknowledging that this is an in-progress project, but you have created a safe, albeit ugly place for their kids that will keep them warm in the winter months. Honestly, my kids all love the basement in its unfinished glory. I don't like it down there, but they will ask to play in the "tunnel" (that's what they call it) all day, every day.