Jeff's second in a three-part series.

Last month, we began our discussion of making mistakes-a significant part of the estimating process. For all estimators, particularly trade estimators, making mistakes remains an occupational hazard throughout their career. Fortunately, there are ways and means by which mistake making can be controlled-if not eliminated completely.

Essentially, there are six major elements to "mistake control." In order of importance they are the following:

o Humility

o Thoroughness

o Consistency

o Intuitiveness

o Regimentation

o Experience


Aside from the actual technical mistake itself, there is the all-important human element that contributes to it. Pencils have erasers because people make mistakes, plain and simple. Quite literally, that is the main reason one should always use a pencil when producing an estimate. It allows one to correct mistakes quickly, easily and cleanly. In my opinion, the only time you should use a pen in the estimating process is when signing your name to the proposal letter.

Once, I was asked by the chief estimator for the company I worked for to train a new estimator trainee. Despite my objections, he insisted he was more comfortable with an ink pen rather then a lead pencil. I strenuously informed him of the hazards of this tack but he was confident that he-unlike others-hardly ever made a mistake.

When he finally completed his quantity survey, I opened the sheets to find a maze of white spots. At first, I thought my eyes were playing a trick on me. Then, I realized that these white spots were the white-out markings he had used to correct all the mistakes which, according to him, hardly ever occurred.

Such sloppiness was not acceptable and he was forced to use a pencil just like everyone else. More important, he had learned a lesson critical to all estimators: humility. Indeed, he had learned that he was fallible and to do his job properly and professionally, he needed to understand this important element of the estimating process.


Important as it is to be humble, it's also important to be thorough. This means checking/reviewing every drawing that is part of the contract set no matter how remote to your trade's work. Also, a careful review of all relevant specification sections, general conditions, scope of work, insurance requirements, project conditions, site inspections, etc.-the entire bid package, in effect. As well, all revisions/addenda must be reviewed and acknowledged.

Very often, in a large bound set of drawings, it can be difficult to see the far left side of a drawing, especially towards the back of the bound set when the drawings are folded over. For this reason, it's important to always make the effort and check that side of the drawing though it can be difficult and awkward. Very often, critical information is to be found there (a note, detail, etc.) I once found a note that stated, "All bathtubs and showers to receive cementitious backer board surrounds." This is a significant cost item. Had I not folded the drawing over I would have missed it. It was on the next-to-last drawing on the lower left-hand side; a very inconspicuous location.

Thoroughness also means not being lazy or lethargic about your responsibilities. The best estimators sometimes have an Achilles' heel when it comes to checking revisions/addenda thoroughly, especially after a bid proposal is submitted. The "out of sight, out of mind" mentality prevails and bids that could have been won are lost and/or critical changes affecting a contract are overlooked. Being thorough eliminates this flaw-the ruination of many an estimator.


There is one rule concerning making mistakes that overrules all others in the estimating process: If you're going to make mistakes, at the very least, make them consistent mistakes.

In other words, if a mistake is to be made, if/when it is discovered, being consistent about it will make it exponentially easier, quicker and more efficient to correct. For example, if one or more floor plans show a standard "double-double" two-hour rated partition around a stairwell and other floor plans indicate it as a 2-hour rated "stair shaftwall" (finished x (2)sides), chances are it will be one or the other throughout-not both. By selecting one and qualifying it, you will have a 50/50 chance of being right. In a case like this, checking the door schedule for the head/jamb details for the stairwell door/frame is always a good way to determine which wall type is required.

If it turns out that your choice for one of the two 2-hour rated walls was correct, then there will be no need to adjust your survey/costing/proposal. Had you chosen the wall type that proved to be incorrect, it is a fairly easy matter to adjust the survey/costing/proposal to reflect the correct wall type. On the other hand, if you included in your survey/costing/proposal the wall types exactly as indicated-alternating from floor/s-to-floor/s between the two wall types-it would be a difficult and time-consuming task to include the correct wall type. Of course there is a chance that the wall type indicated is correct despite the alternating, but it is unlikely. Bottom line: Follow the same logic for all your important decisions and do not deviate from this logic.

Next month, in part three of our ongoing discussion of making mistakes, we'll discuss the remaining three key elements to "mistake control": Intuitiveness, regimentation and experience.