How much plumbing information is usually needed on a drawing for building permit on a small room addition?

Question

Is the locations and types of fixtures enough? Are pipe sizes and details checked during inspections without having to show it all in detail on a drawing?

Answer 1

a  proper riser diagram is usually required  size of drainage pipes proper venting etc. it does not need to be of scale  . it should show size of piping etc  for both domestic water and drainage .

Answer 2

Usually, all you need is a drawing of how many fixtures you are putting in.  it doesn't have to be professionally drawn, or to scale.  If a plumber is going to do the work, he will have to pull a separate permit, because he will need inspections of his work, before any walls can be covered or concrete poured.  If you are doing all the work, make sure you fully understand what is required, because inspectors do not have the time to instruct you on how to do the work.  No pipe sizes are required for the permit, for vents or for water pipe.