The lower level is really a place to make all your own and have fun. It's wonderful to have this extra space, especially during our long winters. A fireplace will make it cozy and add a heat source.
The theater rooms are very popular. We added an area for guests or family members to sit up to a bar area and watch a game or movie:
This family needed an office area and an extra family room:
An unused basement became a comfortable living room and play area for the kids: