Quantity takeoff is a complex process and errors can be costly. Whether done manually or digitally, taking off requires careful input and precise output to be successful.
The right takeoff software streamlines the process and eliminates human error. It uses details from construction plans and designs to analyze, identify and calculate the work scope.
Identifying the Scope of the Project
Performing a quantity takeoff is one of the first steps in any estimating project. A quality quantity takeoff will help you bid accurately on projects and ensure that you have enough materials to complete them. It also helps you prevent mistakes during construction and avoid costly delays.
During the takeoff process, an estimator must review plans and drawings and identify all work items and their associated dimensions. It is important to note that all measurements should be taken “net in place,” meaning that they should not account for waste or other factors that may affect actual material requirements. Additionally, it is important to measure each item in a sequence that mirrors the order of work as shown on contract drawings and specifications. This helps to ensure consistency throughout the entire process.
In addition to identifying the scope of the work, the takeoff must also identify any associated costs. This includes items like labor, equipment and overhead. For items that are sold by unit, such as piping and steel, the estimator must count each individual unit in order to calculate the total cost of the work.
There are many different ways to perform a quantity takeoff, from traditional manual methods to cutting-edge digital solutions. Each method has its own unique advantages and disadvantages, but all of them are designed to improve the accuracy and efficiency of the estimating process.
Identifying the Materials
Whether it is done by hand or with digital tools, quantity takeoff is a time-consuming task that requires attention to detail. During the process, it is easy to make mistakes, especially if one fails to follow sound principles. A small input error can easily lead to a wrong end-calculation, while a bad output error can be costly for the project’s overall success.
To minimize errors during the takeoff process, estimators should double-check measurements and reference all documents, drawings, and calculations to ensure accuracy. They should also stay up-to-date with industry standards, unit costs, and software updates. In addition, they should use a reputable digital takeoff software solution that enables them to perform their tasks with ease and efficiency.
Aside from measuring the dimensions of each item, quantity surveyors or material takeoff professionals need to identify all materials that are needed for a project. This includes any specifications or drawings that provide information about the type and size of a particular component. For example, a concrete structure might require sand and gravel, while electrical or plumbing systems might need pipe, wire, or lumber.
Performing a material quantity takeoff is necessary before offering a quote or bid. With accurate material estimates, contractors can create better estimates that improve their bid-to-hit ratio.
Identifying the Units of Measurement
A unit of measurement is a standard value that represents a physical quantity. Examples of units include length (meter, yard, foot), weight (gram, kilogram, pound), volume (liter, gallon, milliliter) and time (second, minute, hour). Various systems of measurements exist, and each has its own standards and rules defining how to relate them to one another. Traditionally, different countries used different measurements for different types of goods and services. In modern times, the most widely used systems of measurement are the metric system and United States customary units.
Within a single system of measurement, it is easy to express the size of different physical quantities by converting from one unit to another. For example, within a system of measurement using the metric system, you can easily convert between meter and inch by understanding that 1 m is equal to 12 in. You can also use a conversion table to help you understand the relative sizes of other measurement units such as kilometers, meters and centimeters; kg and g; lb and oz; liter and ml; hr, min and sec.
For projects that require a mix of units, the Measure tool provides the flexibility to select either imperial or metric as the default measurement type and format for each project type. This setting is managed in the Units tab of the Options dialog box.
Identifying the Costs
The next step in a quantity takeoff is to identify the costs associated with each material or item. Cost estimators typically break down the design shown on drawings and described in specifications into predefined work items, such as ‘surface area of masonry’ or ‘volume of concrete’. The estimator then applies standardized unit rates to each of the quantities identified to estimate cost. Typical unit rate calculation methods include per square foot, per linear foot and per cubic yard.
Once the estimator has accurately measured and recorded each item, they can then calculate total project materials. This is done by multiplying the number of each item with the associated unit of measurement. This is how the estimator determines a total surface area of masonry, a cubic volume of concrete or the weight (tonnage) of steel and backfills.
Performing quantity takeoffs manually can be an extremely time-consuming process, especially when faced with the challenge of creating accurate estimates while under pressure to meet bid deadlines. Even the smallest misinterpretation or omission can snowball into major mistakes in the final estimate, which can result in an inaccurate list of required materials and unrealistic pricing values. This is why many estimators prefer to use a digital takeoff method, which uses construction estimating software with takeoff capabilities. This approach is more efficient, reduces human error and allows teams to focus their energy on other responsibilities.