Thinking about onscreen takeoffs?
Here’s what you need and what you can do with it.
Plan rooms, electronic files, portable takeoffs: while some contractors have jumped on the digital bandwagon faster than you can say jackrabbit, applying onscreen technology requires an understanding of such issues as file types and where paperless takeoffs fit in the emerging digital job site. And contractors should be clear about their goals. Are digital takeoffs all they’re after? Or are they aiming to get beyond staking and into machine control?
“When CAD was first available and could be imported into automated estimating software,” says Mike Gillum, director of development estimating at Maxwell Systems Inc., “adoption was gradual, partly based on the availability of CAD files. But with PDF capability, adoption has been almost night and day. Contractors who take advantage of digital takeoff software get much more flexibility and function with a PDF file than a paper blueprint. With our Quest digital takeoff software, you can zoom in for a very detailed look at complex plans, including those with multiple industries. We also features such functions as cropping, which makes it possible to select what you need from a plan and make it into a separate PDF. And the industry has shown over and over again that digital takeoffs are more accurate.”
Gregg LaPore, chief executive officer of Trakware Inc.. agrees that if it’s accuracy you want, digital takeoffs are state of the art. “You can bid faster, and you’re able to verify your takeoffs very easily because you’ve got the PDF image of the paper plan and the takeoff on the screen at the same time. And it’s more convenient because you don’t have to wait for paper plans to arrive.
“With a digitizer, you’re running the tip of the pen along a line like a pencil. Being able to zoom in on the drawings and make the image bigger makes that thin line become thicker. Also with the PDF and your takeoff on the screen simultaneously, if you’re sloppy, it stands out like a sore thumb.”
Usability is another feature of working digitally versus tracing paper files. Because digital takeoff files are stored electronically, they’re easy to check and consult—no more hunting down blueprints—and they’re easily archived, which makes keeping track of plan revisions easier.
“It’s a small leap from digitizer to onscreen takeoff using a PDF,” says Jim Jimenez, sales manager for Roctek International. “Customers who have switched to onscreen takeoffs no longer use their digitizers at all. It makes more sense because you’re tracing directly on top of the plan, and you can see what you’re tracing and how accurate you’re being. It also eliminates the cost of securing the plans and ordering additional sets. And in this market, saving costs is what it’s about. If you really need a hard copy, go to Kinko’s. You can make a lot of prints at Kinko’s or the UPS store for the price of a digitizer.”
The Issue of Data Input
But PDF files are not the end-all and be-all of digital takeoffs, especially for contractors who envision a digital job site. For that your software needs the capability to import and manipulate CAD files. “These days the customer is dealing with data from four different formats,” says Steve Warfle, product manager for InSite SiteWork. “These include paper plans, image files such as PDFs, TIFFs, and JPEGs, design files [CAD files] and field data. If contractors are going to use all those forms, they need software that can merge them effectively.” Warfle knows of what he speaks. With an eye toward providing accuracy and usability, InSite initially built its software around CAD files, figuring these would emerge as the industry standard.
“We have had an excellent CAD importer in our software for over 10 years. Two or three years ago, however, we became aware the industry was going with image files. The difference is that JPEGs, TIFFs, and scanned PDFs are all bit maps. A line in a PDF file consists of a white background with groups of dots turned black. Because they are only rows and columns of dots, if you zoom up, you can see these lines are jagged. The instruction to the screen is to turn this or that pixel on or off. So if you blow up a 1,000-by-1,000-pixel page, all the errors will blow up with it. Alternatively in a vector-based program such as CAD file, when you draw a line, it actually contains the coordinates of the endpoints. The computer understands you want a line from here to there and draws it on the screen.
“This means you get a much higher resolution look at that line because whether you make it bigger or smaller, it scales proportionally. It also means you don’t lose anything.” In a word, says LaPore, “A vector file is a series of real numbers where a PDF or a print is just an image and the lines are just dots, which when they’re blown up can be difficult to trace.” And being difficult to trace means spending time doing it.
All takeoff software that relies on PDF input must convert the bit map into a vector-based file for the software to do its calculations. As the lines on the bit map are traced they are converted into the numbers the software needs. Because they are already vector files, CAD files don’t require tracing, and this allows for what is in effect instant conversion. “You bring in your existing, your proposed and any of your subgrade areas such as parking lots, building pads, et cetera,” says Gillum, “and the job is done. You can takeoff a job in 10 minutes that would take you maybe a couple of hours with a PDF.”
“If it’s high-quality data they want,” says Warfle, “I tell our customers they want the CAD file. If they can’t get that, the second best is a PDF, TIFF, or JPEG; the third best, a paper plan.” Jimenez agrees: “Contractors who don’t receive the CAD files never know how easy a takeoff can be.” LaPore is of the same mind. “When you’re working with a PDF or TIFF file, you’re taking off from the screen, but they’re both just images of the plan rather than the plan itself, and you always lose something in the translation. We’re still seeing a lot of contactors saying they can’t get the CAD files, but whenever they can, it’s a no-brainer to go directly into the CAD file for the takeoff. It saves you the time of having to manually trace and digitize.”
Brett Smith, partner in Dirt Pro LLC, 3D model builders in Higley, AZ, makes a case for software that can work with both. “A lot of the time with CAD files, the software won’t bring in the text information, which is generally all of your leader lines with top of curve elevation and pad elevations. There is also the consideration that CAD files often don’t match the paper versions for various reasons, and since contractors can be bound to paper plans, a PDF of the plan is valuable. In the future, you’re always going to want the CAD files, but having PDFs in addition makes it that much better.”
Given the current variability in files, Ed Graham of Digital Canal in Dubuque, IA, stresses that for maximum efficiency and usability contractors who utilize plan rooms should look for takeoff software that can handle the multiple file formats plans may come in. Warfle adds that all data, from paper plans to image files to CAD files, may have errors that need to be addressed. Which means that contractors working with multiple file formats are also wise to look for programs that have tools such as offsets and slope to daylight that make it possible to turn incomplete designs into quality takeoffs. Two-dimensional CAD files-meaning no elevations assigned-will need elevations assigned to the vectors. Other complications a software program needs to address include blocks and exploded polylines, external references, and so on.
“You could make the case,” says Warfle, “that an import would be better and easier if all the errors were fixed before a file is imported. With software like ours contractors can fix the file either in the CAD environment or after it’s imported. The reality is that bad data on a file can include both mistakes and lack of information. And that’s going to be true whether you have a CAD file or PDF. If a contour has a bad elevation assigned to it, it’s going to be on the paper plans and it’s going to be in the CAD file.”
All this being said, a particular benefit of CAD files is they can be used for layout. “A CAD file not only looks perfect on your computer monitor,” says Warfle, “but laid out on the job site, it would be perfect. You snap on a line of a building corner and you get the layout coordinates. On the other hand, on a digitized or traced image, a line width on a 40-scale plan is usually only about a foot wide. So imagine that you’re trying to trace the line and eyeball a corner of a building. Would that be close enough for layout? Of course not. From a calculation point of view for dirt work, it’s fine because we don’t dig these sights with a teaspoon, but you can’t use that information for layout.” This being the case, contractors who are sure they aren’t interested in using takeoff files for layout or to take the leap into machine control modeling may want to stick with PDFs and save on their software investment.
“It all depends on whether you’re doing rough or fine grading,” says Gillum. “What we’re seeing is that most contractors, even though they have the ability to do their own fine grading, are still relying on staking and grading companies. On the other hand, most of what civil contractors and even flatwork concrete contractors do is rough grading, and the PDF file accuracy is fine enough for that. On a small, one- or two-acre job, 1,000 acres, chances are the PDF is going to be good enough for a contractor to stake and lay out accurately.”
Another consideration in choosing takeoff software is whether it can import field data, which can be useful in verifying topos that can help make your takeoff more accurate.
Other Sticky Wickets
PDFs scanned from paper plans may not be to scale. Maxwelll’s Quest pops up “an annoying message” that recommends “compensating the scale for the best and most possible accuracy available.” LaPore issues the same caution. “We make it very apparent to our customers that when they get a PDF, they shouldn’t believe the scale. They need to generate their own scale by finding a known distance, then some other known distance and doing a measurement to verify the program is coming up with the same length that’s shown on the plan.”
Accuracy is only as good as operator diligence. With the image of the plan and the takeoff up at the same time, the screen can get busy. LaPore advises becoming familiar with whatever tools are available in the software to toggle things on and off and double check whether you’ve captured individual lines. “Contractors concerned about errors in plans that can be difficult to see on some screens, have the option to have the plan printed. Or they can get themselves a good 19 or 21 inch monitor.”
Which brings up the issue of balancing accuracy with portability. Gillum recommends a large monitor, minimum 21 inches or alternatively, connecting a laptop used for takeoffs to an external monitor such as the 30-inch flat screens many Maxwell customers are installing in their offices. Contractors who want to do their takeoffs in the field or otherwise need portability are typically stuck with a 15-inch to 17-inch laptop monitor, and their best bet is getting proficient with their software’s zoom feature. For office use, Maxwell has just introduced an interactive system that includes a touch screen in which navigation is with an electronic pen. Check whether the software you’re considering offers an autotrace function, which speeds up the process of converting bit mapped files into vector data (remembering there’s nothing to differentiate a line used for a building perimeter or a curb line in a bit map file, which means auto-tracing must be managed).
Another issue is computing power. PDFs and especially CAD files aren’t small and can mount up. Check with software manufacturers about specifications.
Who in your operation will be assigned the digital takeoffs is another consideration, which could depend on whether you’re using PDFs or CAD files. Jimenez reports receptionists and students doing takeoffs with estimators reviewing the final job. “Whoever does it has to be able to learn what an existing contour or spot elevation looks like and what proposed grades look like. Once you do that, half your takeoff is already done.” Gillum reports seeing contractors separating the takeoff and estimating functions. “The takeoff person will digitize 10 or 20 jobs—maybe somebody does all the concrete takeoff, somebody else the sitework, somebody else all the masonry. They stockpile these for the estimator, who then plays with the what-if scenarios, the building assemblies, overhead, profit, mark ups, et cetera. We’re also seeing a lot of the small- to medium-sized contractors take somebody out of the field or the accounting office.” Western Engineering Contractors Inc. in Loomis, CA, which is heavily into machine control, has one fulltime takeoff specialist and usually two part-timers, typically construction management students who the estimator working closely with to let them know exactly what they’re looking for. “The work they do is fairly standard,” says Vice President John Haskell. “You just tweak it a bit here and there from one job to the next.”
From his perspective as a model builder, Smith makes the argument that experience counts. “Good takeoffs are directly the result of how well someone knows the software. Even with what we consider the best software, we still learn things everyday. And not only do you have to have a good understanding of the software to be able to get to the end result the quickest and most accurately, you also have to have experience with different types of jobs.” Whoever does the takeoffs, LaPore issues a caveat: “Don’t buy the software because you’ve got some huge job due in two days. Block out some time in your schedule, takeoff the example job that comes with the program. Then takeoff a job that you’ve already bid and maybe completed and then verify that. We get way too many people who are learning while they’re bidding and that’s like rolling the dice on your company.”
When choosing a software package Smith also recommends evaluating the availably of technical support. He points out software tutorials typically use cut-and-dried projects that showcase the software with step-by-step directions. “It’s important to be able to tap into support, especially if you’re thinking of layout and machine control.”
File management is another critical factor. “You have to organize everything as it comes in,” says Smith. “We create a new folder every time we get a job. Then within that folder, I’ll create one folder for the PDFs of the plans, and then another to house the CAD files, another for all the bid information and things like soils reports and the bid specifications. Once we start doing the takeoffs, we’ll have our takeoff files in the main folder so that everything is neat and organized.” And don’t forget backup. Trakware recommends USB flash drives to customers and software from www.secondcopy.com.
After Takeoff, What?
When it’s all said and done How far can you go with a digital takeoff?
“I put construction-grade quality into what I do,” says Bruce Flora of Flora Surveying/Data Pro Ltd. in Glenns, VA, which does both surveying and model building. “You would not want to put the time and effort that I put into a model in the estimating phase. On the other hand, a contractor using estimating software to build to and then put it in 3D is going to be very disappointed if he wants to get close. If he’s doing a mass grading and gets it close, the estimating software is fine. But if he wants to do finish and fine grading, he’s not going to be a happy camper.”
Smith puts it more bluntly. “For machine control and actual execution of the job, digital takeoffs don’t do contractors a lot of good. On the other hand, when you do a digital takeoff, you can view the project in 3D, so if your foreman is having an issue staking or looking at a particular area on the plans, he can come into the office and look at the 3D view to find the best way to proceed.
“And if contractors have machine control, they’ve got their base station set up on the job and they have a grade checker out there. With the 3D pocket computer on a rover, a contractor has the power to go out and topo that entire site. So instead of just taking the plans and doing a takeoff with the existing ground information, which could have been an aerial topography that was shot from a plane 10 years ago, a contractor can do his normal digital takeoffs just like always and the grade checker can go out to the site and with his rover do the topo of the actual project site and import that information into the takeoff software. This allows him to compare the quantities in the design against the topo on the plans and the design calculated against the topo from the actual site. So right out the gate before he’s even bidding that job, a contractor will know if there’s a bust in the topo that’s been provided.”
Contractors can also use this kind of a setup for progress volumes. “They can do a topo of the site once a week or every two weeks as dirt is moved and they can bring that into the digital takeoff, replace the existing ground from the other stages and calculate it so they have real time quantities as the job is going along.” Like everyone else, Smith recommends contractors looking to use machine control for layout, staking, and automatic grading should avoid using the design surface from the takeoff. “Not only is it not precise enough, sometimes despite whatever the plans are, grading foremen may change things based on what the surveyor wants for
certification.”
“Taking off the quantities is definitely the first step,” says Tony Vanneman, construction products marketing manager for the Construction Division of Topcon Positioning Systems. “But in terms of the overall process, it’s a very small part compared to the digital job site, which means taking those projects, putting them inside the control box in the cabs of the machines with the operators, putting it in the hands of the grade checker or the foreman with his survey rover and being able to control the job. That’s really where the big money is, on the machines.”
But Randy Nolan, vice president of business development and marketing for Positioning and Machine Control at Carlson Software, where he’s also director of machine control, has a different view. “The ability to do a digital takeoff is an absolute critical step in developing the digital job site. CAD files are the crude oil, and takeoff files are the refinery. We write the software that integrates the processes on a paperless, stakeless job site—that drills for the crude oil, refines it into positioning fuel and uses the refined fuel to position the machines.” And instead of getting stuck is the issue of securing CAD files from designers, Noland wants the industry to push engineers to design in 3D. “Right now they’re not willing to do that, which means the contractor has to invest in in-house data prep or send it out to the data prep companies. But even with that, I promise you if you’re a grading contractor and you’re bidding work, you’re going to lose to people who own this technology. Because they can do it faster and more accurately.”
“The key to technology,” says Flora, “is for everybody to work together and cooperate. And no matter how big or small or how involved he wants to get in machine control, the contractor should learn how to manage data. This means learning how to ask the right questions to get the proper data. And if they have the right person in house, somebody who’s really good at digital estimating and good at construction and can move to the next level, they may want to do the modeling themselves. Because that’s all it is, moving to the next level.”
“Say a contractor has Topcon machine control,” says Gillum. “When you buy that you get a program called Topcon Office. The contractor imports the CAD file, creates the job, comes up with the numbers, exports a machine-control file, takes the machine-control file and opens it up in Topcon Office and based on what he’s learned out on the site, manipulates it or not. Then it goes from Topcon Office into the machine. The process works as long as the contractor has confidence in the CAD file—and in his estimator.
“Do your research. Find out what’s available. Go to the trade shows, ask your competitors and your peers. Find out what’s really out there before you jump the gun.”
“In the future,” says LaPore, “ delivery is going to be all electronic, which means contractors are not stuck in the office anymore. And without digitizers, they can make those estimating cubicles smaller, which means they can pack in more estimators.
“Plus it’s a good excuse to tell your wife you need a new laptop.”