A quantity takeoff is a key step in creating a detailed estimate. It requires a skilled estimator to study project drawings and specifications and know the latest costs. It also requires a lot of time.
Various names for the process include material surveying, construction takeoff, and cost-estimating takeoff. It’s used by architects, engineers, and construction managers.
Accuracy
Inaccurate quantity takeoffs result in project delays, over-budget costs and inefficient project execution. To avoid these costly mistakes, estimators should follow a few best practices to ensure accurate takeoffs.
Takeoff accuracy starts with understanding the scope of work. An estimator should measure each item in the plans and specs based on dimensions that are specified, not scaled. In addition, the estimator should not make allowances for waste, which can lead to inaccurate calculations. The takeoff should also be measured in a logical sequence, following the order of construction that is shown on contract drawings and specifications.
Another important step to ensuring accurate quantity takeoffs is the use of digital measurement tools. These tools can reduce measurement errors and speed up calculation time. They can also improve efficiency by allowing estimators to review large quantities of data quickly and easily.
Lastly, an estimator should always record the drawing number, detail number and grid reference of each item taken off. This can help to identify the locations of each element on the plans and ensure that all items are included in the final estimate.
Material cost estimates are critical for any construction project. They allow contractors to create realistic proposals and avoid expensive rework and delays. Often, estimators treat these estimates as a qualifier or a back-end issue, but they should be at the forefront of every proposal.
Time
Performing a quantity takeoff is a time-consuming task and requires a high level of skill. This is why most construction project managers retain specialized independent takeoff professionals to do this vital data management task for them. It is also why it is so important to get this step right. An inaccurate material takeoff can have devastating consequences in terms of cost and timeliness for the entire project.
When a quantity takeoff is done manually, estimators must spend a significant amount of time in the office preparing and reviewing plans and drawings, measuring and recording quantities. This is because the process relies on paper blueprints, a scale ruler and either a calculator or an Excel spreadsheet with cell formulas. Manual takeoffs are prone to human error and have a high margin for omission and misinterpretation of data. Digital takeoffs can also suffer from errors that stem from poor input or from faulty software programs.
In either case, the result is a significant delay before estimates can be created and submitted to contractors for bidding. This leaves projects vulnerable to losing out on competitive bids or facing delays if materials are not delivered in time for construction. Quantity takeoffs focus on the specific materials required for a project, so other costs like labor, insurance, permits or overhead are not accounted for. However, if the quantity surveyor misses any items or materials, the overall estimate will be incorrect.
Cost
Performing material quantity takeoffs and estimates on construction drawings requires a high level of skill. This is especially true if estimators use manual methods for taking measurements and creating spreadsheet models. While this process may save money, it can also be expensive and time-consuming. Using an automated takeoff solution, on the other hand, can save a great deal of time and eliminate the risk of human error.
Many companies now offer takeoff software that can scan 2D blueprints and convert them into digital versions. This software then enables users to identify the number of conduits, wires and other materials on each page of a plan. The program can also capture information about each item, such as its diameter and insulation color. In addition to reducing the need for labor and saving time, this technology can help builders calculate their material costs more accurately.
As a result, builders can use this data to improve their bids and win more projects. In addition, a reliable estimate helps builders stay within budget and avoid costly project overruns. The bottom line is that a good quality material takeoff process can make or break a project’s success. As such, it’s vital to invest in the right tools and technologies for this essential front-end work. A firm that does so will gain lasting competitive advantage in estimating and building projects.
Communication
An accurate material quantity takeoff is a crucial step in the building process, but it requires specialized skill and a lot of time. Attempting to cut corners or skip this important step can cause errors in your construction estimates that will cost you both money and time.
There are two main methods to perform a quantity takeoff: manual and digital. The manual approach involves a skilled estimator reading construction drawings to determine required materials. This can be done on paper blueprints with a scale ruler and calculator or by using estimating software that calculates quantities automatically. The problem with this method is that there’s a high likelihood of human error — even the smallest mistake can trigger an error in your estimate.
The digital approach uses advanced design software that gleans information from the details in construction documents and automatically calculates material quantities. It can also include labor estimates, but it’s important to note that this feature isn’t available in all design software and may require a bit more effort from the estimator.
A third option is to use a model-based quantity takeoff (BIM), which uses 3D building models to provide the most precise data for material calculations. While this method takes a little more work than traditional digital estimating, it provides a more detailed and accurate result that can feed into a higher-quality estimate.