Average schedule summary times for Design, Procurement, Construction for average buildings - like a school or school add-on

I do not think that there is such a thing since each design is different the site is different. There maybe something based on square footage that you cna use but I dont know of any.

The closet thing would be something like an estimating program like  timberline, richardsons, etc

for actual production rates there is a tab uptop of this page labeled as production rates