Windows are great, but sunshine streaming in makes the place hot and glares up screens, so think shades or blinds if you have sunny windows. Machines generate heat. So do people. Putting both together in a small space can make the temperature intolerable to both. Think about air conditioning.
Air conditioning has another benefit.
It brings more people into the center when days and months are hot, and who knows- they may find something to make them come back. Be sure that you have an entry method in case someone locks themselves in and they can't get out. Make sure you have lots of places for people to dispose of trash. If there's a recycling program in your area, provide recycle bins. If there is no recycle program, encourage your clients to start one.