This reminds me that if I build a play house, I could use lattice instead of fence pickets if I don't want to completely enclose the sides. Might be quite a bit cheaper. Would need to make sure it was sturdy.
One of the drawbacks of high density living is the lack of garden. Here is a lovely way to get some "green space" without spending all your time tripping over pots on the balcony. You'll find many more gardening ideas on our site at http://theownerbuildernetwork.com.au/gardening-ideas/