R&K Building Supplies Window & Door Center is one of the Valley's largest suppliers of windows, doors, hardware and window treatments. The sales office and showroom are conveniently located near the 101 & 60 Freeways in Gilbert. You will find a huge selection of full-sized and functional displays as well as reliable and knowledgeable sales professionals who have years of industry experience to help you choose the best window and door products for your home and budget.