It's always a good idea to add as many points to shut off water flow as possible. If you have water going to two separate areas of your house, put a ball valve in. A ball valve will allow you to quickly shut off the water where you need to, and to do it right away. In an emergency, you'll be glad to have spent the extra dollar on a ball valve and prevent thousands of dollars of damage to your home.
Ball valves and other plumbing supplies can be found at www.supplyhouse.com
