Letters

Your recent columns, "Shop Drawing Review" (CSE 12/02 p. 13) and "Guide to Shop Drawings" (CSE 01/03 p. 15), struck home for me. Where is the split in responsibility among engineer, owner and contractor?

Over the years greater responsibility has been placed on the engineer—with no improvement in compensation. Furthermore, the Request for Information process has been abused. Originally intended as a mechanism for clarifying engineers' intent, RFIs, in some cases, have become a way of generating piles of paper.

In the most blatant cases, engineers are being asked to provide coordination sketches for alternate manufacturers and substitutions that then become the contractor's change orders.

All this starts from a fundamental lack of agreement as to what the design documents represent. At our firm, we design a variety of projects. On a select few of these projects, we assume the role of construction administrator or contractor. The level of documentation varies, but in all cases our design is subject to change, due to changing field conditions, equipment buyouts and product changes, as well as owner-directed changes in scope. The issue is how to protect ourselves and the owner by assuring that contractors properly function as site coordinators.

I believe that the solution lies in a concept called prototypical design. Engineers typically develop a system flow diagram, perform load calculations, select equipment and—based upon the prototype selected—layout the work. To assure competitiveness the engineer names alternate equipment that is of equal quality, can meet the anticipated duty and will customarily fit in the allocated space.

What an engineer doesn't do is prepare alternate designs to reflect the nuances of equipment connection points, supplemental service connections or clearances for access. As a result, a layout drafted around a selected prototype manufacturer might not apply to the alternates. It's even less likely to work for a substitution offered by the contractor.

So how do we address this issue? I suggest that the American Institute of Architects documents be modified to reflect the reality of design practices. Appropriate language would include the following:

Prototype: A product or group of products from an identified manufacturer that was used as the basis of systems layouts and installation details. Prototype products are those scheduled on the drawings or in the specifications, or those which are referenced in the contract documents as being prototypes.

Alternates: Products or manufacturers that will be in compliance with the performance and quality provisions of the specifications and may be proposed for use by the contractor.

Substitutions: Products of unnamed manufacturers or a different model number from those identified on the documents. Substitutions must be justified on the basis of need, cost or both, as long as there is no identified reduction in quality and that all design parameters are met.

The contract documents are based on prototypical design where identified vendors and products are used to prepare the system layout and to identify all utility connections. These drawings, even when dimensioned, are schematic in nature and are subject to field coordination to reflect actual conditions, final equipment shop drawings—which may vary from the document which were furnished at the time of design—and the contractor's means and methods as well as coordination between trades.

It shall be the contractor's responsibility to coordinate the final installation of all equipment and systems. Where alternate manufacturers or substitutions are incorporated into the work, any architectural or engineering design required to incorporate that work shall be the responsibility of the contractor, as is any cost resulting from changes in layout, increased sizes or lengths of run of services or for any additional utilities that may be required by the use of alternates or substitutions.

Any changes in the project required to support alternates or substitutions shall be fully identified and submitted as an adjunct to the shop drawing for the alternate or substituted product. In addition, such changes shall be reflected in the coordination drawings and shall be approved by all affected trades.

This is a start at addressing the issue. I feel very strongly that if properly addressed, many such issues could easily be resolved, and the responsibility for site coordination will once again be properly placed—in the contractor's hands.

Mark L. Brecher, P.E., Manager, Mechanical Engineering Process Facilities, Inc., Philadelphia