While there's no set age to help you determine the right time for a redesign, most tweens will send clear signals when they're ready to upgrade their space. Some kids will start to complain about their "babyish" decor, while others may simply express an interest in redecorating. If your child has yet to mention his room but you notice he barely fits in his kid-sized bed or desk, it may be a good idea to start planning a room that will suit his growing body.
Quite often, the room you designed with a toddler's or child's needs in mind simply doesn't fit the needs of a pre-teen, who likely has much more on his mind than his favorite toys. Tweens will also start to require appropriate space for their daily activities, including studying or grooming. As your children start to spend more time with their friends, they'll also look for a comfortable and cool hangout space with just the right amount of privacy.
Some families choose to make updating the kid's room a rite of passage in the summer before he or she starts junior high school. This helps to remind kids who may be nervous about the start of middle school that with change comes new perks and the first taste of independence.