Recently, I was surprised to read a report that indicated that while architects and specifying engineers believe that we ultimately control the specific products used in our projects, contractors and wholesale distributors change those specs between 30% to 50% of the time! Changes are mostly due to striving to win the job, based on the lowest total aggregated bid. Business is won and lost based on the bottom line. So, it is in their best interest to substitute what they feel are equal products that can be had at a lower price.
It is common these days for specifiers to focus primarily on the big picture with regard to any project or idea. However, it's often the details that determine whether a project successfully portrays the engineer's original vision. Leaving the details to people who have a different motivation often leads to acceptable results rather than excellent finished projects. As an engineer, I believe excellence is as much about detailed specifications as it is about the project concept.
The cost-value equation has always been an important part of the relationship between the project owner and the design engineer. It maintains the equilibrium of projects, delivering a finished product that fulfills its function, while making everyone associated with it proud of their work. Not every project can be specified with top end products and not every project should be"