Quantity takeoff is the first step for anyone involved in construction project planning. It involves examining blueprints and calculating the number of materials required for a building, structure or project.
This can be done manually with paper blueprints, a scale ruler and a calculator or via digital methods using construction estimating software with takeoff capabilities. Either way, ensuring accurate results requires high-quality data management.
Estimation
There are a lot of things that can go wrong during a quantity takeoff. The simplest way to avoid these problems is by ensuring that the takeoff is complete. This includes reviewing all the construction drawings, making sure that nothing has been overlooked and analyzing the work package. It is also important to ensure that all the necessary calculations have been made. In addition, it is important to remember that omissions are the leading cause of cost overruns on large construction projects. It is not uncommon for even experienced estimators to omit soft costs like permits or less-obvious costs such as touch-ups. By using a checklist to avoid these errors, you can be confident that your quantity takeoff is complete and accurate.
Quantity takeoffs help determine the scope of a project and give you a realistic understanding of what is expected to achieve your project’s overall goals. They help you improve your bidding process, save time and money, and eliminate rework or speed bumps in the project.
If done correctly, the output of a quantity takeoff can be incorporated into a pricing system and used to produce a proposal. This is where a construction estimator’s true skills are displayed. It is vital that you accurately identify the materials and quantify them, which will then be incorporated into your pricing model to generate a realistic project proposal.
Planning
An accurate quantity takeoff is a critical step in the project planning process. It helps estimators evaluate different materials and construction techniques, leading to better project outcomes. It also enhances decision-making and facilitates bidding and contract negotiations. In addition, it serves as a reference point for changes in scope, making it easier to manage change orders.
Quantity takeoffs can be performed manually or digitally. The manual method involves interpreting blueprints and using a scale ruler, calculator, or computer software to calculate the quantities. However, it takes a significant amount of time to do this and is susceptible to human error. Moreover, it is not a suitable option for projects that require a large number of measurements.
The digital method eliminates the need to interpret drawings and use a scale ruler, saving time and improving accuracy. It is also more cost-efficient than the manual method, but it requires specialized software. Nevertheless, it is worth the investment because it offers many benefits over the traditional manual approach.
Before starting the takeoff, an estimator should carefully study the plans and specifications. Then, they should determine the scope of work and record the dimensions of each item. It is important to measure each item in its net in place state, rather than relying on scaled drawings. It is also necessary to double-check calculations and cross-reference the measurements with the construction drawings and specifications.
Preparation
Getting accurate quantity takeoffs done early on in the construction process can help to enhance the bidding process and avoid rework and speed bumps in the construction process to come. This part of the planning stage is known as estimating takeoffs or material takeoffs and requires an experienced engineering firm to accurately prepare and deliver these estimates. The takeoff process is based on a review of plans and specifications and involves identifying and determining the amount of materials, work hours, and other project inputs required to complete the job.
Quantity takeoff is a crucial step in the bid preparation and contract negotiations process. It provides project stakeholders with valuable data that helps them make informed decision-making to optimize project outcomes in terms of cost, quality, and time. Quantity takeoffs are also critical for assessing and managing risks in construction projects.
A traditional method of doing a quantity takeoff involves manually scanning 2D blueprints to create digital versions and then using software tools to calculate the physical quantities of various construction components. However, this method has a high risk for error, especially when working on large-scale projects, and it can be very time-consuming.
Despite the fact that digitization has greatly improved the accuracy of quantity takeoffs, human interpretation and error remain the primary cause of inaccurate estimates. To ensure a high-quality estimate, a team should include a qualified estimator and a takeoff specialist who can manage the data management process. Moreover, the estimator should verify BIM models that will be used for the takeoffs. This step will significantly improve the accuracy of the estimation results.
Output
The output stage of the takeoff process involves creating a material list that is used to produce a cost estimate. This can be done using a number of different methods, but the best approach is to use an enhanced cost estimating service, like 1build, which uses next-generation technology and world-class estimators. This allows builders to get a detailed material takeoff that will help them to create a realistic project proposal.
The construction industry depends on accurate quantity takeoff to ensure that all materials are accounted for and that the total price of a building structure is correct. Every door knob, floor tile, hinge, length of pipe, or piece of carpeting needs to be counted and accounted for in order to create a comprehensive material list. If the takeoff is not conducted correctly, it can lead to inaccurate estimates that will ultimately impact project budgets and schedules.
Estimators typically prepare quantity takeoff by counting work items on a set of plans or models, and then converting them to material quantities. This is a time-consuming and error-prone process, which is why many companies have turned to BIM for a better, more accurate way to conduct quantity takeoff. BIM uses 3D models to make it easier for estimators to verify counts and measurements, which helps them reduce errors in their calculations. According to RII results, a BIM-based approach yields more reliable estimation results compared to traditional CAD-based methods.