Creating a reliable estimate is no easy task. As contractors in the construction industry, it’s important to reduce (and preferably eliminate) risk. A fundamental skill that estimators must learn is how to do a quantity takeoff reliably, consistently, and thoroughly.
Quantity takeoff (also known as “material takeoff” and sometimes abbreviated as “qto”) is counting (or “quantifying”) the number of devices and any required equipment, as well as the length of feeders, branch, and cabling on a specific project. Material dollars and labor hours are then associated with this quantity takeoff. This takeoff becomes the foundation of the rest of the estimate. With this information, the estimate will begin to take shape with schedule analysis, crew sizing, mobilizations, lost time, supervision, incidental labor, any potential overtime to cover schedule accelerations or squeezes, and much more.
A short and simple quantity takeoff is often provided on smaller tenant improvement (TI) projects. It is provided as the scope of work to clarify the subcontractor’s understanding of the work. Quantity takeoff can also help with determining changes to the design in the future, thus making change orders easier to process, with clear expectations set between the General Contractor and subcontractors.
While misses are inevitable (and human), they can become costly. If, for example, an estimator misses a single fixture in a particular location, their estimate might be short by a couple of hundred dollars per hour. But what if that fixture is actually an ornate luxury chandelier weighing 150 pounds, and likely requiring electricians for proper installation? Now, one simple miss becomes a budget gap that the project manager and field must strive to cover, be that through making up lost time in other locations or through change orders.
One more example: an estimator is working on a new hotel and taking off hotel room typicals. During takeoff, the estimator misses (1) Duplex Receptacle in each room. If the hotel is small with only (12) units, it’s likely not a big deal. But what if this hotel has hundreds of rooms and that particular receptacle is on an isolated circuit? Again, one simple mistake can quickly become extremely costly and force the team to determine a way to cover their costs or seek reimbursement.
Complete, thorough quantity takeoff establishes a solid foundation upon which to build the rest of the estimate. While an estimate is never exact, trustworthy takeoff establishes a baseline of commodity material cost and labor hours that are needed to determine greater pricing questions. Can the contractor purchase enough materials to negotiate for better pricing with a vendor? Will the crew be large enough to necessitate multiple foremen, thus requiring a General Foreman? Are the drawings clear enough to produce thorough takeoff so that the final bid can afford to have more aggressive overhead and markup?
Takeoff can make or break a project. If an estimate does not have solid takeoff, it can feel as though the estimators are making ill-informed guesses. Rather than producing a bid that is within a comfortable difference from a competitor, an estimator could find their final number to be orders of magnitude away from their competitors.
The beginning of a well-managed job starts with good quantity takeoff. Without it, how will a project manager know if their project is going in a positive direction? By way of example, when managing a personal budget, it’s important to know what’s being spent and where it is being spent. Similarly, it is important for an electrical contractor to know how many devices they will need to install on a project, how many they have purchased, how many they have already installed, and how many more they will need to install. Any specialty equipment or switchgear should also be carefully tracked and noted for long lead times.
New drawings and addendums will often be released both in the process of bidding a project, as well as during construction. If an estimator is bidding a project at multiple stages of drawing development, General Contractors will often want to know what the differences are between the last round of bidding and the current one. Solid quantity takeoff in the first round, and equally thorough takeoff in the most current round, will help to answer this question.
During construction, it is common to ask a different estimator to produce a new estimate that serves to double-check the work of the estimator who won the project. This estimate is called a construction estimate. It has the express purpose of simply verifying and validating the true cost of the bid that won the project. If the original bid and the construction estimate are drastically different, the management team will have identified a problem early and may be able to find ways to capture these costs. If the original bid and the construction estimate are close, then the management team can have strong confidence in the estimate and focus on maintaining their key indicators.
At the early stages of a project, an estimator is responsible for producing quantity takeoff. The devices that an estimator takes off are drawn by architects and engineers, but architects and engineers are not typically concerned with the exact number of takeoff items in the same way as an estimator. Architects and engineers want to capture the design of each room, the power requirements, the code restrictions, and many other details. Estimators, however, are concerned with capturing the material cost and labor hours to produce an accurate estimate.
During the bidding stage, estimators may call upon specialty trades and subcontractors to perform their own quantity takeoff of the project. Low-voltage systems such as Fire Alarm, Security, and Structured Cabling are often called upon to produce their own quantity takeoff and estimates.
After a project has been awarded, some companies will have preconstruction managers perform their own quantity takeoff as a form of construction estimate. Again, this estimate is designed to validate or find holes in the bid that won the project.
During construction, project engineers and project managers may be called upon to produce quantity takeoffs for change orders, as well as their own updated construction estimates to track the anticipated success of a project.
Whenever it is necessary to produce an accurate cost, whether for bidding purposes or for project management purposes, it is a good time to produce quantity takeoff. Contractors are often brought into the bidding process very early in development, and budgets or rough orders of magnitude (ROM’s) will be produced with only knowing the type of project and anticipated square footage. Most contractors will want to perform quantity takeoff as soon as drawings are available in order to verify (or adjust) their budget.
It is also helpful to complete quantity takeoff when large design changes have occurred. It is challenging to stand behind certain values when an estimator is aware of reroutes and redesigns. When such changes inevitably occur, it is best to perform takeoff again.
Until the advent of digital takeoff software, traditional manual methods using highlighters and takeoff worksheets were industry standard. An estimator would print off the drawings, lay them out, and begin to highlight various devices, all while meticulously counting and writing down the quantities on a takeoff worksheet. Their takeoff would often be separated by drawing for organizational purposes. Branch would be “rolled” off using a manual measuring tool and recorded on the takeoff worksheet.
The clear benefit of this approach is that an estimator had the potential to have a very good understanding of their project. Given the proper time and determination, an estimator would pore over each drawing and become quite familiar with the drawings.
The downsides of this approach are also clear when juxtaposed against modern takeoff software. Manual takeoff is more error-prone due to human error and limitations of manual tools. Was the estimator interrupted while performing takeoff? Did the estimator leave off on 52 or 53 duplex receptacles? Is that a “7” or a “1” scribbled on the takeoff worksheet? Was the estimator allowed enough time to perform takeoff, or did the estimator need to create plugs and use loose averages in order to meet a deadline?
Takeoff software has significantly changed the construction industry with its increase in accuracy and speed, allowing for more accurate quantity takeoff, more intricate bid breakouts, and faster turnarounds. An estimator need only download the drawings from a website or FTP and begin takeoff with their estimating software of choice. Most software (and even some web-based software) have tools designed to count devices and trace lengths. This digital information can often be exported as a spreadsheet and organized in many different ways. The flexibility of exporting and organizing this quantity takeoff allows estimators multiple approaches to inputting their quantity takeoff.
Digital takeoff provides estimators with powerful tools to produce extremely accurate information. It also allows for greater opportunities to double-check an estimator’s work. Particularly clean-looking quantity takeoff can also be easily used as presentation material for interviews with General Contractors and clients.
The downsides of digital takeoff is also its strength: extreme accuracy, many robust tools, and many ways of exporting quantity takeoff. Estimators can get lost in the accuracy and produce quantity takeoff that would not be possible during construction. For example, a conduit run on a drawing may only be 7 feet, but during actual construction 10 feet of material would need to be purchased and handled in order to complete the work. Also, too many complex bid breakdowns can cause confusion and misallocations of devices and cost. Overall, however, digital takeoff is quickly becoming a standard within the construction industry for estimators. These downsides pale in comparison to the power and accuracy of onscreen takeoff.
Performing takeoff using manual methods? Print the drawings, pick them up, lay them out, grab a highlighter and start counting! For digital takeoff, download the drawings, open them up, open your software toolbox and begin clicking! Quantity takeoff itself is truly simple at its core: count “stuff,” measure distances. This is where the estimator’s understanding of the trade and experience in their role comes into play. How many wires are required for this many circuits? To what degree will this run need to be derated if I combine circuits? While some software, like Drawer AI, can answer these questions, most cannot. An estimator needs to remain engaged during the quantity takeoff process and ensure not only that they are accurately capturing their takeoff, but also that they are properly organizing and understanding it.
It is best practice to review frontend documentation and project-specific specifications prior to beginning any takeoff. Proper review will help the estimator ensure that they are visualizing the proper installation methods while performing takeoff. While specifications won’t often change the counts of devices, it can more heavily influence branch and feeder routing depending on the preferred installation methods.
Whether working alone or on a team, estimators would be best served by determining standard methods of estimating. Specific colors can be used to denote different types or stages of takeoff (for example, “pending,” “captured elsewhere,” “performed by others,” etc.). Typical highlighting or counting methods can also be helpful to reduce points of failure in an estimate–this is especially helpful when working on a team.
For example, if an estimator takes off a card reader, does a single count represent the card reader device only, or does it also include the door contacts and any associated conduit? The same idea can be applied to a duplex receptacle; does a single count represent just the duplex receptacle itself, or does it also include a conduit stub to get into the ceiling space? Maintaining a consistent approach will help improve takeoff quality, communication amongst estimators, and confidence in bids over time.
Once some estimating standards are established, estimating software can be implemented to make quantity takeoff input a more seamless process. Currently, most onscreen takeoff software does not come with estimate-producing software. An estimator may takeoff a duplex receptacle, but the takeoff itself is a simple count–in this case, “1”--no material dollars or labor hours are associated with it. Estimating software applies material dollars and labor hours to these counts.
One of the strongest methods of takeoff input is utilizing an estimating software with prebuilt or user-modified assemblies. Most estimating software will typically have some way of creating assemblies by utilizing user-programmable quantities of individual items. For example, a (1) duplex receptacle assembly may have something like…
Takeoff reviews, both individual and with a supervisor, can help to determine the quality of takeoff. A typical individual review will typically happen while the estimator is performing takeoff whether consciously or subconsciously. It is common to make adjustments to takeoff throughout the duration of the project as an estimator becomes more familiar with the project scope. These adjustments are more plentiful at the beginning of the project, and will gradually decrease during the bidding phase.
Towards the end of bidding, it is good for an estimator to review their takeoff with a supervisor or a project manager. Typical reviews will begin with a general overview and understanding of the estimator’s approach, followed by spot-checking various elements of the takeoff to see if there are any odd or repeatable errors that may have occurred.
Once the quantity takeoff is reviewed with minimal adjustments, it is typically ready for use.
The most apparent challenge while performing takeoff is when an estimator discovers that crucial information is missing. This can be the location of an electrical panel or the omission of a symbol on a legend, or a missing drawing. The most straightforward solution is to create a Request for Information (RFI) and submit it to the General Contractor. There are times, however, when an estimator will have to make an educated guess due to time constraints. Should this occur, it is often best to seek out the opinion of a project manager or a general foreman to assist with properly capturing unclear scope.
Nothing is more challenging than trying to hit a moving target. Scope changes during the bidding process are often released as addendums. The more frequent these addendums are released, the more challenging it is to organize and perform quantity takeoff. It is challenging for an estimator to capture minor changes while maintaining takeoff from previous sets of drawings.
Scope changes are more challenging and more frequent when preparing an estimate for a Design-Assist or Design-Build project. In these types of projects, the design is normally created concurrently with the estimate. This can make an estimator’s role of accounting for clear scope (via quantity takeoff) and risk (via allowances and budgets) a daunting task.
In these instances, it is best for an estimator to try to be proactive with the engineers: ask questions in an attempt to understand what they’re trying to create. It is also helpful for an estimator to read any design narratives that the engineers are referencing. Takeoff should be approached very generally at first, and then become more focused as the engineers clarify their own design. Managing risk and expectations will be crucial for the estimator when scope changes are occurring quickly during the bidding process.
After award and during construction, scope changes will become nearly inevitable. At this point, an estimator will often have the luxury of being able to slow down and wait for all the pertinent information before performing takeoff.
Other notable, but often preventable, challenges include user errors and input errors, ignoring addendums, ignoring email correspondence, ignoring challenging field conditions (especially if offered a job walk), and outdated plans. With most of these scenarios, an estimator can avoid frustration by being engaged in the project. Not only will it help the estimator to perform their role, but it will also grow the general contractor’s trust and confidence in their final bid.
Without trustworthy quantity takeoff, an estimate is really just a guess. An estimator can improve their takeoff by avoiding challenges, engaging with the drawings and narratives, standardizing their takeoff methods, and staying up-to-date with best practices and best software in the industry.
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