Parents actually complained that the paint was peeling on the windows? Seriously?
Anyway we have found that the way we behave and present things in the gym plays a big role in the way the kids behave.
We have a strict rule that there is no food allowed in the gym and the only beverage allowed in the gym is water. If the kids need to have an after school snack they can sit outside and eat it before class. If the parents need to feed their kids after their pre school class before taking them home then they can sit outside and have it. It makes it a lot easier when there is a clear rule. If a kid or parent pulls out some food or a juice box we can just say "sorry there is no food allowed in the gym, you can eat it out there if they need a snack". We also don't sell food or drinks, we find this causes too many problems. We have a water cooler and water is available to all gymnasts and parents when needed and that is it.
If books and magazines are being thrown around the place remove the book/magazine rack. By providing these things for parents you are encouraging them to stay and sit through the classes. We of course always welcome parents to stay and watch classes, an open door policy keeps things safer. I like the fact that a parent can feel comfortable to come in at any time and watch what we are doing with their child. But providing a lot of services to keep kids/parents entertained is sending a different message.
Kids on equipment is a big one. If one or to kids before class or one or two siblings decide that its ok to wander in a play on the equipment this can quickly escalate to a big problem. It also sends the message to kids that the gym is a playground and when they are in class there is less respect for the class structure. We have our gym fenced off and only a coach is permitted to open the gate (the handle is high enough that no little ones can open it anyway). There is a clear sign on the gate staying that students may not enter the gym without their coach. If a child attempts to enter the gym, be it class member or sibling we have no problem just stating the rule "your not allowed in the gym without your coach". When the boundaries are clear few kids (or parents) feel the need to test them. I think its important for coaches to realize that they do have a right to say something, if a sibling is in the gym getting in the way of the classes, don't wait for the parent. It may not be a class member but the gym rules apply to all who enter the facility and the coaches have every right to tell a little brother or sister to hop off the equipment.
We don't mind kids being dropped off early, the older kids often come straight from school and wait around doing homework until their classes start or a parent drops off susie to gym class early on her way to dropping of Johnny to soccer and so on. Again the rules are clear, you can go in the waiting area but not passed the gate until your coach invites you. They do not enter the gym, occasionally they try it and it is quickly dealt with. It worries me that some have reported that kids come early for class, then run around the gym and continue to do it despite being corrected. That is a problem of serious concern, it shows that the kids have no respect for the coaches and the rules of the gym. This problem will continue once the class starts. If a child is removed from the gym to the waiting area, yet ignores the directive and returns to the gym there needs to be some sort of consequence or it just becomes a game for the kids. Do you have a time out area where kids go when they are not prepared to follow the rules. If a kid goes back into the gym after being removed then they should be sat there. There needs to be clear consequences or kids see it as a game.
If we have a kid who has this testing nature and comes in and decides to try and get away with continually entering the gym without permission we simply state to the kids "OK, if you are not prepared to listen and follow the rules you won't be allowed to do gym today, I'll give your parents a call to come and pick you up". Once I actually had to get the phone but it has never got any further than that. The kids will get away with anything they can, just to see what they can get away with it. Once they see the boundaries are clear and there is no way around them then they tend to settle and behave well.
