The quantity takeoff plays a critical role in the construction industry. General contractors and subcontractors use it to determine the construction materials required for the project and the materials that need to be delivered to the job site. Accurate quantity takeoffs are critical to winning construction jobs that turn a profit.
Key Takeaways
The quantity takeoff (QTO) is an integral part of the construction estimating process. During the takeoff, the estimator analyzes the construction drawings and quantifies the required materials for a construction project. These quantities are used to determine the material costs, which are incorporated into the project’s total cost. They are also used to order the materials.
You need accurate quantity takeoffs to win profitable work. A takeoff that includes more materials than required unnecessarily increases your bid and the chances of losing the bid to a more competitive contractor. On the other hand, a takeoff that is missing materials might lower the price and increase the chances of winning the bid, but you’re stuck covering the cost of the missing materials, increasing the chances that you’ll lose money on the project.
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As I said, accuracy in the takeoff is key when ordering materials. If too many materials are ordered, they will have to be returned, which incurs additional shipping costs and possibly a restocking fee. When too few materials are ordered, additional materials must be ordered and shipped, which can lead to construction delays and loss of productivity while waiting for the materials.
The Goldilocks principle applies to preparing a takeoff. It can neither be too high nor too low. It needs to be just right.
Construction professionals establish a standard workflow for the takeoff process, which helps them prepare accurate estimates by ensuring they don’t miss any items during the material takeoff. Each estimator needs to establish what works best for them. Some start the takeoff at the bottom of the building and work their way to the top, while others may take the materials off in the order they appear in the MasterFormat®.
Regardless of the order in which the materials are taken off, estimators need to keep track of what has been quantified and what still needs to be taken off. One way to do this is to mark off the items on the plans as they are quantified.
Construction professionals also develop Excel templates to help them determine the required materials in less time. Developing well-tested templates also acts as a checklist, making it harder for estimators to miss materials. For more information on developing spreadsheet templates, see Construction Estimating Using Excel, which contains sample spreadsheets for many construction materials.
The takeoff process is different for different materials. Some materials, like doors and light fixtures, are taken off by counting them. Other materials are taken off by the foot and converted into a number of pieces. For example, wood plates and studs are taken off by measuring the length of the wall and converting the length into the number of feet of plate and the number of studs. Others are taken off by the square foot and converted into the number of sheets, like OSB sheathing and drywall. Some materials, like excavation and concrete, are taken off by their volume.
Regardless of how they are taken off, the quantity of materials needs to be converted into the units in which they’ll be ordered. For example, the square footage of the roof’s surface area needs to be converted into rolls of underlayment and bundles of shingles. For more information on the construction takeoff for specific materials, see Estimating in Building Construction.
When taking off materials, estimators need to add materials for waste, which may be inherent in the design. For example, if an 11-foot-wide room is carpeted with 12-foot-wide carpeting, there will be a foot of waste along the entire length of the wall. Additional waste is needed for construction errors (like miscut materials) and damaged and stolen materials.
Additionally, estimators should note in the takeoff any special requirements that need to be considered when ordering the materials. Suppose there isn’t a local supplier for a particular material or the job is in a remote location. In this case, the estimator may want to order extra materials because the cost of delaying the job exceeds the restocking costs. Similarly, project constraints, like having to use an elevator to transport the materials, need to be noted. In this case, some materials, like door frames, may need to be assembled on the job site.
Estimators also need to record the quantities needed to calculate the labor required to install the materials, which may be quantified differently than the materials. For example, the labor to frame wood walls may be priced by the linear foot rather than the number of studs and lineal feet of plate.
Additionally, estimators should note any conditions that will increase construction difficulty, labor requirements, and equipment costs. Materials requiring different labor or equipment requirements should be kept separately in the estimate. For example, an 8-foot-high concrete block wall is precisely 12 blocks high and can be easily constructed. On the other hand, a 7-foot 10-inch-high wall requires the top block to be cut along the entire wall, dramatically increasing the labor costs and requiring additional saw blades. Additionally, taller block walls require more labor and equipment than short walls. Taller walls require scaffolding and hoisting the materials onto the scaffolding.
When preparing a takeoff, the materials must be separated into the types of materials provided by different suppliers to make it easier for estimators to send the list of materials to the correct suppliers. The suppliers will then provide the estimator with the material prices, who will compare the prices and decide where the materials will be purchased. The bids need to be leveled when there are differences among them. Bid leveling involves adding or subtracting money from the bids to adjust for differences in the bids.
Estimators must determine if the bids include transportation costs and sales tax. If they are omitted, they will need to be added. If the materials will be delivered before they are needed, the estimator needs to include the cost of storing and rehandling them.
Digital takeoff software is used to automate the takeoff process from digital copies of the project plans. Using construction takeoff software is often less time-consuming than performing manual takeoffs. Some construction management software, like Procore, includes takeoff tools.
Some software can streamline the process by taking off several quantities simultaneously, saving time while producing accurate takeoffs. For example, some software can quantify the volume of concrete, area of forms, and surface area to be finished by selecting the slab's perimeter. Some software can automatically count symbols representing building components, such as doors.
When using takeoff software, you should always verify that the drawing’s scale has been accurately set by measuring a known length in the up-and-down and left-and-right directions.
Good takeoff software allows the amount of materials to be imported into construction cost estimating software, which determines the project costs and is used to prepare the bid. Integration of the takeoff and estimating software eliminates the need to enter the quantities into the estimating software.
The functionality and features vary among the software packages. There are different types of takeoff software for various types of construction. Some takeoff packages are geared to building construction, and others to civil projects. Some software is cloud-based, while others run on local computers. When considering purchasing takeoff software, consider how each package meets the company’s needs, the anticipated labor savings from using the software, and the cost of the software.
Estimators play a critical role in a construction company by preparing the company’s bids. Without accurate bids, the company will either lose jobs because its prices are too high or win work that it cannot make a profit on. It only takes one lousy bid to bankrupt a small general contractor. Preparing an accurate quantity takeoff is an essential skill for estimators and a crucial part of preparing an accurate bid. One of your most important hires as a GC is hiring an estimator with the skills to prepare accurate estimates, including precise quantity takeoffs.