You’ll pardon me, but I seem to have forgotten something important. Of all the topics I’ve covered in this column over the past 10 years, I believe I have overlooked an aspect of commercial construction estimating that can only be described as foundational. Of all the documents that an estimator confronts in his endeavors, none may (or may not) affect an estimate as crucially as the structural drawings. Oh, I’ve touched on the subject here and there, mostly as a secondary mention while making another point. But the dilemmas that a set of structurals may present to even the wariest of bidmeisters merits some singular attention.
I say “may or may not affect an estimate” because, as we all know, most structural drawings these days omit heavy gauge structural framing, as the engineer of record shifts the responsibility for the design of exterior studs over to the framing sub in the form of a deferred submittal—required shop drawings produced and stamped by a licensed structural engineer. All, of course, generated at the expense of the framing/drywall sub. A design team may on occasion, however, elect to address the heavy-gauge framing within the preconstruction drawings—that is, over and above the generic “typical framing details,” which commonly consist of two or three “one-size-fits-all” depictions that rarely, if ever, address the actual conditions proposed.
Either scenario presents the potential for multiple “gotchas.” In the rare event that the construction set of drawings presented by the design team includes numerous details involving exterior metal stud framing, some bidmeisters are left scratching their heads. In fact, the inclusion of sufficient structural details has become so rare, even old-school exactimators have become rusty on the approach, while newbie quantifiers are completely befuddled.
The first rule of thumb that some of us may have forgotten is that the structural drawings trump the architecturals in every case. The reason for this is clear: The components and fastenings that make up the critical underlying structure of a building are supported by irrefutable calculations, while the conceptual details of an architect are generally based on little more than aesthetic whimsy. Nevertheless, it may be tempting to rely on the architectural details, which are almost always less stringent than the structurals and more open to our own interpretation on how to build this or that assembly. But make no mistake, when it comes to a conflict between the two, an inspector or GC super is going to refer to the structural detail, holding fast right down to the size and number of screws, welds, clips and kickers. Obviously, the wise quantifier will use the structural details to cover his assembly.
Most experienced estimators have developed a good shortcut approach to distinguishing metal stud details from other structural details that commonly number in the hundreds on a typical commercial project. They go straight to the details pages at the end of the set and highlight or list the number of each detail that clearly depicts the incorporation of metal stud components in the assembly. They then backtrack to each plan page and highlight or “hot link” where the corresponding number of each relevant condition appears and applies. Every bidmeister who has gone to this extent knows that the structural details are typically more plentiful, more stringent and contain more components and fasteners than their architectural counterparts, and therefore require a great deal more time and attention. But experience tells a seasoned estimator to not take any shortcuts here, and those who choose to succumb to temptation due to the usual time constraints do so at their own peril.
But the scenario above seldom occurs these days. I personally have seen metal stud framing included in the structural drawings maybe twice in the past five years. The deferred submittal scenario—the one in which the framing/drywall sub provides the shop drawings—has become the norm, and it comes with its own set of difficulties.
First and foremost, the deferred submittal situation compels the estimator to base his conditions/assemblies on his own assumptions (and we all know what happens when we assume). How vague the basis is for those assumptions depends on certain degrees of familiarity, factors such as how conversant the estimator is with common structural standards; how well-acquainted he is with the structure types (i.e., steel or post-tension concrete; bypass wall conditions or slab-to-slab, etc.); how familiar he is with the engineer he intends to use and with the components and fastenings that engineer typically employs. He may or may not be comfortable with contacting the engineer for some basic pre-bid tips.
In any case, the framing estimator is basing his takeoff on his own unique interpretation on what the project will require, while each competitor will be using his own interpretation in his takeoff rather than a common set of details. It’s easy to predict what kind of difficulties this will create in a scope review in terms of comparing apples to apples. Throw in the cost of potential upgrades, latent rejections and the cost of the drawings themselves into the mix, it becomes clear that the deferred submittal model tends to muddy the waters for the framing estimator (or rather, prognosticator).
Vince Bailey is an estimator/project manager working in the Phoenix area.
