What is a Quantity Takeoff in Construction?
Quantity takeoffs are an important aspect of the construction cost estimating process. Quantity takeoffs are used in both large and small projects to determine actual costs, ensure that a project remains profitable to the contractor, and are a vital component of a final detailed estimate. General contractors, subcontractors, quantity surveyors, and estimators routinely produce quantity takeoffs during the estimation process. While some in the construction industry may not routinely work on quantity takeoffs, they may still wonder what is a quantity takeoff in construction? This article will seek to answer this question by defining what a quantity takeoff is, what the components of it are, and how it fits into the construction estimation software process. We’ll also look at the different ways quantity takeoffs are completed, and what the advantages and drawbacks of these different methods are.
What is a Quantity Takeoff?
Although quantity takeoffs are themselves complex, they have a simple purpose. You may also hear a quantity takeoff referred to as a construction takeoff. A quantity takeoff is created to provide a list of all of the materials necessary to complete a project. A quantity for each material will be provided, hence why they are called a quantity takeoff. Along with the required amount of each material, the estimator will compile a comprehensive list of costs for the associated materials.
In order to produce a quantity takeoff, the estimator or contractor will need to work off of drawings, blueprints, or models. From the design paperwork, the estimator will prepare a list of each material needed to complete a construction project. Up until relatively recently, preparing a quantity takeoff required a high degree of skill, as well as good judgment and critical thinking skills. While these skills are still necessary, the barrier to producing an accurate quantity takeoff has been reduced in some ways through the use of digital estimation software with an integrated ability to produce digital takeoffs.
Quantity takeoffs fulfill an important function for construction projects of nearly any size. Quantity takeoffs are an integral part of the cost estimation process. The information from a quantity takeoff is incorporated into a final detailed estimate, along with things like labor costs, office overhead costs, subcontractor costs, and equipment rentals. Given that material costs represent a sizeable portion of total construction costs, the quantity takeoff must be accurate and up-to-date.
Quantity takeoffs are generally performed early on during the bidding process. During the estimation process, an estimator may have to make frequent adjustments to there quantity takeoff. This may be due to design changes, additional engineering requirements, or changes in what the client wants. Because of this, the quantity takeoff is often a living document that undergoes many changes until a design is decided upon and a bid is secured. While this may not be the case for smaller projects, large or complex projects will almost certainly require many revisions to the quantity takeoff.
What are the Components of a Quantity Takeoff?
Quantity takeoffs are used to provide a list of all of the materials required for a construction project. Quantity takeoffs also provide costs for each material. These are the basic elements of a construction quantity takeoff, but it is worthwhile to dive deeper into the other components of this type of takeoff. This provides a better understanding of what is required for a quantity takeoff, as well as how one is constructed.
The first part of a quantity takeoff involves putting together a list of all of the materials required for a project. This will include all raw materials, like lumber, concrete, asphalt, and steel. In addition to raw materials, the quantity takeoff will include any prefabrication in construction that are necessary for the project. The term “takeoff” refers to this process of “taking off” all of the materials for a project from a design drawing or blueprint. As part of this process, the estimator or contractor will need to note specifics about each material. For prefabricated items such as light fixtures, a simple count will usually suffice. For materials like lumber, the quantity takeoff would include what specific type of lumber the job requires, the length and width of the lumber, and may include the total weight of the required lumber for shipping considerations. Taking another example, a quantity takeoff would detail all of the steel piping required for a project and would include details about the length and width of piping, and ensure that the piping that will be ordered will meet design specifications.
There is a high level of detail required when quantifying material in a construction takeoff. Each material must be specified so that the correct material is ordered, and so that the price estimate reflects real-world costs. If the estimator is producing a quantity takeoff manually, they will need to be comfortable performing complex calculations. Materials like concrete and asphalt will need to be quantified in volume, whereas materials like flooring or tile will need to be calculated using area or square feet. Providing the correct quantity for the material is essential, so estimators will need to be familiar with construction conditions, the materials that are used, and a good understanding of the construction process. This last point is because a quantity takeoff will also need to include a certain amount of extra material to account for wastage during the construction process.
After an estimator has compiled a comprehensive list of the materials required, their specifications, and their quantities, the estimator can then begin to prepare a material price estimate. Quantity takeoffs fulfill two basic functions in a construction cost estimate. First, they detail what materials need to be purchased to complete a project. Second, they provide a total material cost for a project, which is then incorporated into a detailed cost estimate. In order to determine a total cost estimate, the contractor or estimator will need to determine the cost for each specific required material. Determining the price of materials can be accomplished in a number of ways. For large projects, the estimator would seek a bid from a material supplier. For other projects, estimators may use a personal database of material costs, or draw information from a third-party construction costs database like RS Means. This process will vary depending on who is preparing the cost estimate. For example, subcontractors may routinely prepare quantity takeoffs that include the same materials. If the cost of those materials is known and stable, the subcontractor can simply plug in their known prices into their quantity takeoff. For larger projects, determining the itemized material costs and arriving at a total material cost can be very time-consuming.
Once prices for each material have been determined, the estimator will then produce a total material cost estimate. Most often, the person preparing the quantity takeoff will markup the total material costs. How much or little of a markup occurs will depend on a number of factors, and can be a key determinant of whether a bid is accepted or rejected. A markup for material costs is necessary for most projects to ensure a project remains profitable for the contractor.
Material costs can rise over time. Not accounting for the increase in material costs will impact the profitability of the project. This is especially true for large projects or projects where prices for critical materials like lumber or steel rise quickly over a short period of time. Determining what factors may impact the total material costs, and therefore applying an appropriate markup to account for cost fluctuations is one of the most difficult jobs of a cost estimator. Clients will often accept bids from multiple contractors for the same project. If one contractor’s material costs are significantly different from another contractor it may raise some suspicions.
Types of Quantity Takeoffs
Quantity takeoffs are prepared by a wide range of people and organizations within the construction industry, and each quantity takeoff can be unique. Each individual or organization may find a method of preparation for their quantity takeoffs that they prefer and may format their final quantity takeoff cost analysis in different ways. Despite the unique nature of each quantity takeoff and the various ways they are approached, there are two broad types of quantity takeoffs. The oldest form of quantity takeoffs is completed manually. Recently, digital takeoff software has become increasingly popular for preparing takeoffs. Let’s examine these two different types, and highlight the positives and negatives of each approach.
Manual Quantity Takeoff
A manual quantity takeoff is simply a takeoff that is completed without the assistance of digital takeoff software. In the past, manual takeoffs were done completely by hand. An estimator would examine physical drawings or blueprints and painstakingly create a list of materials. Many people still complete quantity takeoffs manually, but do so with the assistance of computer software that information is entered into by hand. Although still aided by a computer, the process is still largely manual. If done by hand, the estimator must make complex calculations. If done with a computer, software such as Excel can be used to perform certain calculations.
Digital Quantity Takeoff
Digital quantity takeoffs are completed using a construction cost estimation program that contains digital takeoff capability. As you could assume, there are many benefits of using construction estimating software to run your calculations. Although each program has its own suite of features, the basic process of creating a digital quantity takeoff is roughly the same. First, a blueprint is uploaded or scanned into the program. From there, the program analyzes the blueprint or drawings and generates a list of all of the required materials. At this point, the estimator can make any adjustments to the material requirements that they see. They may increase requirements for certain materials where wastage is common during the construction process. Any complex calculations required for assigning quantities to materials are embedded into the program, making this process vastly easier than a manual quantity takeoff. From there, the estimator can apply prices to each material. If the software has the capability, price information can be drawn from a database of current prices populated by the contractor. Alternatively, some takeoff software can draw cost data from online construction cost databases such as RS Means. Once prices are applied to each material, the estimator can dynamically adjust the price to account for material cost increases.
While manual quantity takeoffs are still widely in use, they are slowly falling out of favor due to the clear advantages that digital quantity takeoffs provide. Digital takeoffs improve over manual quantity takeoffs in a number of ways. First, digital takeoffs help reduce errors associated with quantity takeoffs. They do so by drawing information directly from the blueprint, which adds a layer of redundancy to ensure that the estimator hasn’t missed any materials. They also do so by integrating the calculating function into the program itself, which eliminates the need to perform complex calculations. Second, digital takeoffs take much less time to produce. This reduces labor costs associated with producing a quantity takeoff, while also allowing the contractor to seek other opportunities and bid more projects with the time they save.
Quantity takeoffs don’t just save time when creating a takeoff, but they also save time when a quantity takeoff has to be adjusted. This happens frequently during projects. Digital takeoff software allows for a rapid turnaround time if adjustments are necessary. Lastly, digital quantity takeoffs require less specialization to complete than a manual takeoff. For manual takeoffs, the estimator must be extremely knowledgeable about the project, the construction process must understand how to read and interpret blueprints and drawings, and must be able to perform complex calculations. With digital takeoff software, many of these functions are integrated into the software itself. This allows people that aren’t professional estimators to produce accurate and comprehensive construction quantity takeoffs in very little time. To be sure, a quantity takeoff is still complex. The process for creating a quantity takeoff demands a high attention to detail and thoroughness. That being said, digital takeoff software facilitates the production of quantity takeoffs by automating many of the more tedious aspects, while also ensuring that takeoffs are accurate and produced in as little time as possible.
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