When we fenced in the chickens, we used 4 foot tall poultry fence. It didn’t take the chickens long to discover that they could fly over.
To solve that problem, we cut 3/4 inch boards and connected them to the metal fence posts with zip ties and attached 7 foot tall deer fence with more zip ties.
This is a cheap solution that was easy to install, but it doesn’t over winter very well. When the snow is the heavy wet stuff, it tends to bring the deer fence down.
Here are some photos of this years repairs.