About buildings:

The goal is to have >= 3 buildings in queue

You can see that if building turns 'yellow', it recieves only 7+ building points when you build.
Hence the overall building process in guild is slowed.
You'd better focus on another building if first one turns yellow.

Assuming our guild size and building members it'd be good to have 3+ buildings in queue so members have an opportunity to spend building points to the maximum