Why have I put this on the web?

I have been a Hydraulic Consultant for over 20 years, and during this time, I have found it amazing how many Architercts/building designers leave the DP locations to the hydraulic consultant.
I have had a large single storey commercial building where the Architect refused to have a DP anywhere on the outside (or the inside) of the external walls.
This resulted in a 225mm dia storm water pipe in the false ceiling.

And I have had a ten storey building where the Architect didn't mind the DP's on the external walls for the full ten stories.
The point is, every Architect prefers something different. The size and location of the DP's can have a major effect on the appearance of the building, and hence is best left in the realm of the person charged with that responsibility.

Therefore, if Architects/building designers can easily determine the number and size of DP's required, they can complete the building to their satisfacion, and leave the Hydraulic Consultant to worry about the plumbing design, and not get involved with the building's appearance.
Obviously the Hydraulic Consultant will still be required to offer advice on unusual cases, and to check and certify the final storm water design.
If the building designer would like the Hydraulic Consultant to position DP's, then they must realise that generally the Hydraulic Consultant likes the look of pipes, wants them to be accessible, and located where any leaks won't cause a problem.

Box gutters are similar, in that they can have a major impact on the roof framing. The location of DP's and overflows, can also have an impact on the aesthetics of the building.
Therefore if the Architect can have a simple tool to determine all the "what ifs ?" the roof can be largely finalised before being presented to the Sructural and the Hydraulic Engineer.
I am hoping that this will save a lot of time and agro for all on the design team .

Regards,
Ken Sutherland