Spaceshaper 9-14 has been developed by CABE and Wakefield-based arts and architecture organisation Beam. It explores what young people think about how local places can be used and improved.
Bristol and Kent Architecture Centres have also been involved in developing the activity tool kit, which has been used in 14 pilot workshops.
In Hinkler Green Park in Southampton, children said they wanted their local park to feel wilder and include more plants and flowers. Their views have been incorporated in a funding bid.
Balls said: "I hope it will help capture the ideas of young people when new public spaces are being planned or improved. I want to encourage even more young people to get involved in the development of public spaces."