Thank you for all the great tips. My girls are 6 years old and 5 months old. Belle, my oldest, is very smart (in my opinion). She understands numerous commands and hand signals. Daisy, the baby, tries to mirror Belle. So far she understands sit, stay, down, and come. She doesn't hold her stay too long but we are working on that. I am excited to get my boys, 19, 14 and 12 involved in creating a work area. PVC is easy to come by....my husband sells pipe for a living. You have opened my eyes to looking at this differently. I love the cost saving ideas and the chance for the boys to build something together. I will keep you posted.....