Estimating. By its very name, hardly an exact science. And in the slim-margin world of design and construction, a critically important yet monumentally complex task.
Some say the practice is more art than science. But because it is ultimately about numbers, estimating is also a task that is ripe to be handled by technology.
Many in the industry point to the estimator as the least automated Building Team member, the most resistant to new tools and new ways of doing things. But estimators counter that there is good reason for caution. Much of the responsibility for winning or losing a bid, and how much profit a firm ultimately makes on a job, sits squarely on the estimator's shoulders. These risks seem to hold many estimators to stay the course with tried-and-true solutions.
The status of a project bid will often determine the type of estimates required. Some projects call for separate estimates for the bid, the budget, and the design stages. Different levels of estimates also require varying degrees of detail. Therefore, the ultimate approach taken on an estimate is a combination of what the client wants to see, the type of estimate being performed, any requirements the estimator's corporate parent may impose, and the estimator's own personal choice.
For decades, the tool of choice for most estimators has been some sort of customized version of the standard spreadsheet. It's not unheard of to have estimators on staff who are still going strong with software that was personally programmed as far back as the early 1980s.
Thus, at some firms, what you'll find in use is a totally custom package, perhaps years or even decades in development, that exactly reflects a particular method used by that firm or individual estimator to bid work. No wonder many users don't want to give them up for some newfangled system.
Software tools and databases
For software tools, the two general categories boil down to using either a standard spreadsheet, such as Microsoft Excel, or a dedicated software program. Dedicated program users outnumber spreadsheet users about two to one. However, the ratio tips much more toward dedicated programs when a design is fully fleshed out with more quantifiable details.
Many estimators stick with the same system year after year, but it isn't necessarily the software that keeps them coming back. The engine powering most estimators' software is the database that supports the program.
Commercial databases are available with pricing information broken down by type of product over an area as precise as a single Zip code. But construction prices fluctuate, depending on lots of factors: geographic region, the status of the economy, labor demand, even macroeconomic trade issues, such as the use of imported versus domestic steel.
Estimators complain that the data in commercial databases is either too general or too old. Very often they'll settle for nothing less than calls to local suppliers to find out the latest material prices. They also turn to their own staff to find the latest labor prices. Often, in fact, the favorable rate for skilled labor that a general contractor might get because of its close relationships with a subcontractor can also help that contractor get the job during the bid phase.
Various types of estimates, such as conceptual or "hard money," often require different databases. Most software programs don't use or include multiple databases, which is precisely why some estimators cling to their spreadsheets. The ease of creating a customized summary report for a client also favors the spreadsheet.
Takeoffs and landings
Doing quantity takeoffs is the grunt work of estimating — the tedious process of extracting great volumes of information from drawings. Just as an odometer measures the distance traveled in a car by counting the number of revolutions of the wheels, the takeoff wheel enables the estimator to measure lengths of spaces on drawings, so as to be able to calculate the quantities of materials needed for the job.
Over the past 10 years, the takeoff wheel has seen considerable development as a computing tool. One popular model is the ScaleMaster from Calculated Industries, Carson City, Nev. A digitizing pad that connects to a computer, such as one made by GTCO CalComp, Columbia, Md., is another tool used by estimators to help pull quantities together. By overlaying blueprints on pressure-sensitive Mylar pads, then tracing the lines, estimators calculate quantities and input them into the computer in one step.
The upcoming estimating technology is working directly on the computer screen with a takeoff viewer program and a mouse. With a CAD drawing shown on the screen, estimators use a mouse to trace lines and symbols, while the computer highlights the areas covered and automatically counts the materials being highlighted. Users also like the highlighting, because it tells exactly which parts of a drawing have been counted and which are pending.
Houston-based On Center Software offers On-Screen Takeoff, which helps users quantify lengths, areas, and volumes, perform counts, and print color-coded drawings and takeoff lists. One requirement to use the software, though, is having the CAD files. With designers still hesitant to pass around digital versions of their drawings, contractors are increasingly asking for CD-ROMs from reprographic houses.
The push from design-build
Looking even further ahead, the explosion of the design-build process increasingly has designers using estimates as a working tool in the design process. That trend may help propel the longer view some industry technologists take, which is that database-integrated 3-D models will someday eliminate most of the estimating work now done on paper.
"Estimating today consumes a lot of time and creates a lot of bad feeling," says Ken Stowe, a self-described consultant to advanced buyers and providers of A/E/C project delivery and a former director of project services with Boston-based contractor George B.H. Macomber Co. "What's one of the worst things an estimator wants to do? Recount the same 200 doors five times. But it happens all the time."
Stowe says by creating an integration between an estimator's cost model and the 3-D model, thousand of project man-hours each year can be saved. Turnaround times for estimates could be cut to four days from three weeks, and a typical veteran estimator spending up to 20 days a month poring over drawings, doing quantity takeoffs, could reduce that time to about two days.
Doing takeoffs, says Stowe, is often a misuse of the estimator's true skills, which should be "more about analyzing better ways of getting a piece of equipment to a rooftop, or looking at different ways to construct things."
Matthew Phair (firstname.lastname@example.org) is a New York-based writer who explores innovation and technology in the engineered construction process.
|For product information|
|ScaleMaster: www.calculated.com||GTCO CalComp: www.gtco.com||On-Screen Takeoff: www.oncenter.com|