I designed and built my own fence and gate--and it was approved by my town both in my design and after completion. The keys were:
1) 4' high
2) No gap on the bottom
3) only verticals from the outside
4) verticals are <4" apart.
The gate is even tighter--the verticals are 1.75" apart. It uses Magna Latch self-closing hinges and a MagnaLatch that is about 5' off the ground. I don't know if I can post a picture but I'll try--at least a link.
