Project North vs True North?

[OADesign]

Hi All,
So I'm working on some Evacuation Maps and I normally use "project north" from the plans supplied by the contractor/customer.

Today customer responds to a proof asking, "What should I be using, Project North vs True North? I don't know, you are the expert."
It took all of me not to respond, "Yes, I am the expert so why are you questioning it?"

But since I have never been asked the question before, I thought I would ask the experts...

When drawing evacuation maps, what do I use, Project North vs True North for the orientation pointer?

Thanks in advance.

 

[PRS Bryan]

I always use project north. When I was working as a landscape architect we would pull north off the survey, the same place architects get it.

As a result all graphics will relate to the same orientation. I have never known anyone, at any level of design to use true north.

In addition the difference between true north at this scale is inconsequential. Only when navigating long distances (sailing, driving, or hiking) from established maps is true north relevant to me