Mega-Construction (Stellaris)

Hi all, can anyone suggest where is the parameter responsible for the number of simultaneously created mega-structures? they are built for a long time,but this problem until I decided increasing bonus masters of builders(but somehow not interested when the construction of such facilities goes fast). And that's where setting the number of simultaneous construction I never found. resources accumulate faster than time to build the construction and build several structures at the same time is not given,so it would have the bonus of speed of construction was removed,put a few structures to build, and all at once. In General, anyone knows tell me.