Today, it is a common practice among agencies at some levels of government, and by consultants who design projects and write specifications for government agencies, to permit the use of "equal alternates"—products or materials other than those originally specified and intended as a first choice. In general, this is a bad idea.
Those who condone specification changes argue that it keeps design and project costs under control. Among other arguments, proponents claim that the practice promotes a greater degree of open competition between contractors, innovative designers, and material suppliers.
Further, an unspoken advantage to permitting alternates is that it supposedly reduces the possibility that manufacturers and contractors can fix prices. It is argued that when only one type of specified product is allowed, the list of providers is restricted, and prices tend to be higher than necessary.
This may be the only advantage to permitting equal alternate specifications, but I believe the disadvantages are far more important.
Of course, price fixing is illegal, and that, in itself, might be considered a sufficient reason for allowing alternate specifications. But, there are many other reasons to preclude them in any project.
For example, I know of at least one state that permitted fully coated and paved corrugated metal pipe as an equal alternate to reinforced concrete pipe. I also have noted three alternatives allowed on at least one highway guard rail project a few years ago. In that case, aluminum, concrete, and steel all were specified as permissible installations. (Wood was not mentioned.) It is clear to me that cutting financial corners by permitting an alternate material to replace the one that the designer—the professional engineer—had in mind is a selfdefeating practice. The bean-counters in the administrative offices of a highway department are making a mistake when they overrule the professional, who ultimately is responsible for the safety and long life of a particular project.
It also is obvious that when an alternate design is permitted, it can result only in the cheaper of the two being selected by the contractor, regardless of which material is better-suited for the job. If the lower-priced product is exactly equal to or better than the one that was specified originally, then no harm is done, and perhaps some benefit is derived. But, it is substantially impossible to achieve true and total equality in two different materials, products, or designs when they are inherently different.
One of the most serious disadvantages of permitting the contractor to make a decision regarding specifications is that it shifts some of the responsibility for the ultimate success of a project out of the hands of the qualified designer(s)—who must sign off on the work—and puts it into the hands of those who have minimal responsibility and whose main interest is not quality but cost and profit.
In fact, an engineer may carefully design his or her work and not even be aware that other, perhaps inferior, materials will actually be used. Sadly, decisions made by the contractor, rather than by the engineer, might affect the safety of a completed project.
For instance, a former employer of mine permitted alternate specifications on certain materials and products. In one case, it wasn't until a year or two after I had finished a design that I learned that contractors, at their discretion, had the option of changing what I had planned originally.
One of the main features along major highways today is the proliferation of sound barriers. Concrete, wood, and metal products are used in constructing these abominable, if useful, eyesores, and the different materials have different sound attenuating characteristics.
Is it possible that alternative designs, as dictated by contractors, often are not as good as the specified originals? Additionally, sound barriers can be ugly, and the degree of ugliness can be enhanced or detracted from by alternate specifications.
The durability of sound barriers also varies for different materials. Does concrete last longer than wood in this application? I don't know the answer to that question, but the contractor should not be the one who makes that decision. Are there many states that permit the contractor to dictate the material used in the walls they construct? I hope not.
Alternate specifications encourage low-cost materials to penetrate into a market, competing with products of higher quality. For example, many years ago, asbestos materials (almost entirely discredited today) were popular for use in sanitary sewers, replacing clay or concrete pipe. Some were installed in my town with disastrous results. Eventually, they were banned by most, if not all, jurisdictions because of the innate danger to asbestos workers and to pipe users.
This column is not about the relative quality of the materials and products mentioned, with the exception of asbestos cement pipe. It is about the idea of permitting alternates to be used at the discretion of anyone but the original, qualified designer(s). Alternate specifications? In general, they're a bad idea.
Alfred R. Pagan, P.E., P.L.S., is a consulting engineer in Hackensack, N.J. He can be reached at 1-201-441-9719; or e-mail him at email@example.com.