To: "INTERNET:seaint(--nospam--at)seaint.org" <seaint(--nospam--at)seaint.org>
Subject: How best to spend the design dollar.
From: Mark Gilligan <MarkKGilligan(--nospam--at)CompuServe.com>
Date: Thu, 24 Jun 1999 23:58:49 -0400
Chris Willcox, wrote:
<Thus, in the end the
whole debate boils down to my time (= my company's money) vs. the client's
money. If the client is willing to bear my added cost for using LRFD
fine, but for small projects it just doesn't make sense. If the steel cost
8% of the total building cost and LRFD saves 10% of the weight (a very high
assumption in my understanding) and the material cost is one third of the
erected steel cost, then you've saved a grand total of 0.25% of the project
cost. Now for high rise projects where 0.25% is a lot of money and the
savings from LRFD might approach that 10% assumption it's probably worth
I would suggest that on your average project you will make many decisions
that will have a greater impact on project budget than 0.25% of the project
cost. Many of these decisions will be subjective. As a result I would
suggest that optimization of steel sizes may not be the best way to spend
the clients money. There are likely to be other ways to generate more
savings for the same design dollar.
Much has been made about our obligation to give our client the least
expensive design. If the client pays us the additional cost to design
using LRFD, are we fulfilling our obligation to our client if it costs more
to design with LRFD than we can save in construction cost? If you
believe that spending the additional time on LRFD that you will provide
your client the most bang for the dollar then go ahead.
If our fee is not adequate to do the necessary work, do we have an
obligation to produce an optimum design if it means that we will not get
paid for our effort? I recognize that on some projects we have a
contractual obligation to produce a design consistent with the project
budget but in many instances the budget is not a major problem, When the
structural construction budget is too high we may find more effective
stratagies for saving construction costs.