architect-engineer material selection

huangyhg

architect-engineer material selection
hello everyone,
i just completed a job where the architect sent me drawings for a three story stair tower that is being added to an existing building.  the stairs and handrails were shown to be constructed of structural steel.  i designed them as such.  when i took the drawings to the arch. the princaple asked why the stairs were steel and not wood.  i said because that's what you were showing.  most jobs of this nature i have seen, the stairs have been steel mostly due to fire code and durabiity issues.  now the owner wants them redesigned in wood.  don't most of you have the architect show the type of material they would like used and then if there is a problem then bring it up with them, otherwise design it with the materials they show.  thank you.
one of the common dilemnas that you have when working with other people.  imo if he sent you drawings showing steel then it would be reasonable to assume that he wants steel.  if he wants to change it to wood, then you should be able to charge him for additional time.  realistically it may not be worth it to charge for it as it may leave a bad taste in his mouth (although it is his fault).  i would stress to him that you base your design off of the drawings that he sends you, so he needs to know what he is sending you.
absolutely-
if you were designing with materials not shown in the architectural drawings (just picking your own), there wouldn't be a whole lot of use for the architect because you would be "re-doing" and negating his work.  
you are right, you design based on what they show.  if there is a problem (e.g. material isn't strong enough, durability issues, etc...) you bring it up to the architect and come to a consensus.
my standard contract states that the structural design will be "based on the architectural drawings provided by name on date."  that phrase was added specifically to address this issue.  if an architect is going to function as the prime professional, then he has an obligation to act like it.
as jrse i have spelled out in my contracts with owners and architects the scope of work. if such scope of work states that the owner wants metal stairs, then a change in the material is considered a change of scope of work and additional fees apply. by the way, what kind of relationship you have with the architect, as the principal's statements sound contrary to minimal life-safety design assumptions.
if you do decide to eat the redesign, i suggest you show that cost and an offsetting "marketing" or "goodwill" credit on your invoice so at least you get "something" for your frustration.
don phillips
no good answer for this. you are the structural engineer so the selection of materials and systems has to be, at least, partially your responsibility. the best way to protect yourself is to discuss the system with the architect but it has always been my experience that the engineer is ultimately responsible for his system unless specifically directed.
ron,
i would agree would you if it was an innapropriate material selected, but it is the architect that dictates the look and feel of the building, we just make it work.
if the item is covered with finishes then that is another matter.
that is a good point. still better in hindsight to verify with your client.
having worked for an a/e firm for more than 25 years, i would bet that this is a case of the architect's principal not being aware of what his people are doing (normally called supervision), and then wanting to change it after after the consultant has already designed it.
good luck!
jike.....you hit the nail square on the head i think!!