Jeff's third installment on the discussions of error.

In this, the third part of our ongoing discussion of "Making Mistakes," we will conclude our examination of the six major elements of mistake control.

Last month, I discussed in detail the first three of these six elements:

o Humility

o Thoroughness

o Consistency

This month, we'll examine the last three. They are in order of importance:

o Intuitiveness

o Regimentation

o Experience


As you gain experience as an estimator, you will also gain an intuition about things relevant to the estimating process. Sometimes, it is just a hunch or a nagging suspicion in the back of your mind. In reality, this is your intuition at work. It is your subconscious mind informing you that something is amiss. Maybe it is a detail that is over- or under-designed, a section that doesn't make sense, missing information, etc. All these things can contribute to the estimator making a mistake-either by error or omission.

If you think something is "fishy in Denmark," it probably is. Learn to trust your intuition and use it effectively when all other means at your disposal are exhausted.

One time, I had an intuition about a job I was working on. There were many horizontal duct offsets occurring in bathrooms but the reflected ceiling plans did not indicate dropped soffits/ceilings to "hide" these transfer ducts as is typical in mid/high-rise apartment buildings. My intuition told me that there must be dropped soffits/ceilings in all these bathrooms despite the fact that they were not indicated on the RCPs and finish schedule.

I proceeded to check all the bathroom elevations and all showed a horizontal line at 8 feet, 0 inches AFF-the typical floor-to-deck height was 8 foot, 9 inches. Though it was not defined, I suspected this horizontal line represented a requirement for a drop ceiling at 8 foot, 0 inches AFF in all bathrooms. Though it was just a hunch, I included in my formal bid proposal an add-alternate price to furnish and install suspended gypsum board ceilings in all bathrooms. In this way, I need not have inflated my base-bid proposal while at the same time offering the GC/CM a logical/possible additional-cost alternative. As I suspected, my add-alternate brought to the fore this design ambiguity and indeed, a suspended gypsum board ceiling was required in all bathrooms, even those without mechanical/electrical/plumbing offsets.


Just as the athlete training for the Olympics follows a strict regiment of diet and exercise, so too the estimator must follow a strict regiment of processes and procedures for each and every estimate. Regimentation provides a "guide" by which an estimate can be successfully produced every time. Typically, regimentation in the estimating process includes some of the following:

o Logging-in of bid-documents

o Familiarization/Indexing

o Feasibility review

o Referencing process

o Formatting the survey sheets

o Color-coding

o Quantity survey (rough/finish)

o Summations

o Cost Analysis

o Proposals

o Negotiations

In each of these stages mistakes can and do occur. The key is to understand the kinds of mistakes that can be made in each of these steps and follow a regiment to avoid the mistakes whenever possible. For example: In the color-coding process, all suspended gypsum board ceilings may be color-coded in yellow. If a gypsum board ceiling is indicated in a specific room by the RCP legend and/or finish schedule and it has not been colored in, it was most probably overlooked in the quantity survey. Uniform, regimented color-coding procedures eliminate and highlight such an oversight.


The old maxim goes, "there's no substitute for experience." Very true, particularly in the estimating process. The five preceding mistake control measures I have discussed this month and last are interdependent on the estimator's growing experience over time. The subtleties and nuances of the estimating process must be experienced before they can be learned.

Perhaps it is a familiarity with a particular architect's design and his or her ability. Maybe it is the knowledge that a certain GC/CM is notorious for distributing incomplete bid documents or insists on unreasonable bid dates (to increase the pressure on you resulting in mistakes and oversights).

There are a multitude of factors-both human and technical-that contribute to the estimating process. You must set aside any of your pre-conceived notions and deal with the realities of the design/construction industry on a daily basis. Experience is the best teacher for this.

Albert Einstein once said, "The only thing that gets in the way of my learning is my education." This means unlearning some of the things that you were taught and learning by experience, the way the real-world of construction cost estimating operates. For this to happen, every day must be considered a learning experience.

Next month, in Part 4 of our ongoing discussion of "Making Mistakes," we'll examine some of the variety of mistakes common to the estimating process and sight examples of each.