Both large and small projects use quantity takeoffs 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 quantity takeoffs aren’t part of everyone’s role in the construction industry, it’s still a good idea to have some knowledge of what one entails should you find one in front of you.
This article will seek to answer this question by defining what a quantity takeoff is, its components, and how it fits into the construction estimation software process.
We’ll also look at the different ways to complete quantity takeoffs and the advantages and drawbacks of these different methods.
Table of Contents
What is a Quantity Takeoff?
Although quantity takeoffs can be complex, they have a simple purpose.
A quantity takeoff provides a list of all of the materials necessary to complete a project. Each material will have a quantity alongside it, and the estimator will compile a comprehensive list of costs for the associated materials.
To produce a quantity takeoff, the estimator or contractor will need to work off drawings, blueprints, or models. The estimator will prepare a list of each material required to complete a construction project from the design paperwork.
Until relatively recently, preparing a quantity takeoff required a high degree of skill and 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 construction estimation software with an integrated ability to create digital takeoffs.
Quantity takeoffs fulfill an essential function for construction projects of nearly any size and, therefore, 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 costsEquipment rentals.
Given that material costs represent a sizable portion of total construction costs, the quantity takeoff must be accurate and up-to-date.
What stage in the project should a Quantity Takeoff take place?
Quantity takeoffs are generally performed early on during the bidding process.
During the estimation process, an estimator may have to make frequent adjustments to the quantity takeoff, typically due to:
- Design changes
- Additional engineering requirements
- Changes in what the client wants.
Thus, the quantity takeoff is often a living document that undergoes many changes until a design is decided 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 provide a list of all of the materials and costs required for a construction project.
However, it is worthwhile to dive deeper into the other components of this type of takeoff to understand better the requirements for a quantity takeoff and how one is constructed.
The first part of a quantity takeoff involves putting together a list of all the materials required for a project, including raw materials like lumber, concrete, asphalt, and steel.
In addition to raw materials, the quantity takeoff will include any prefabrication in construction necessary for the project.
The term “takeoff” refers to this process of “taking off” all 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.
However, for materials like lumber, the quantity takeoff would include things like:
- The specific type of lumber the job requires
- Length and width of the lumber
- 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. It would include details about the length and width of piping and ensure that the piping that will be ordered will meet design specifications.
How details does a takeoff need to be?
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 perform 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 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 prepare a material price estimate.
How are costs measured in Quantity Takeoffs?
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. 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 several 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 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 several factors and can be a crucial 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 applying an appropriate markup to account for cost fluctuations is one of the most challenging cost estimator jobs.
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.
Why ensure Quantity Takeoffs are done right?
While it can be tempting to skip parts of a quantity takeoff or just make guesses, this will defeat the purse of one - to understand the costs associated with the project.
Missing out on a couple of seemingly unimportant materials or guessing quantities means that the actual project cost could be much higher than the one you end up with.
It’s not only about pricing; guessing things such as material amounts means you could be left requiring more materials, extending the project timeline, or being left with a surplus of unwanted materials.
Quantity takeoffs are time-consuming, but whether a project is big or small, it’s worth getting right the first time around.
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 preparation method 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 entirely 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 computer software assistance that information is entered into by hand. Although still aided by a computer, the process is still mostly 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 specific calculations.
Digital Quantity Takeoff
Digital quantity takeoffs are completed using construction estimating software that contains digital takeoff capability.
Although each program has its own suite of features, the necessary process of creating a digital quantity takeoff is roughly the same.
First, a blueprint is uploaded or scanned into the program. Following this, the program analyzes the blueprint or drawings and generates a list of all the required materials.
At this point, the estimator can make any adjustments to the material requirements that they see. They may increase requirements for specific 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 more straightforward 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 (like Proest) 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.
Advantages of Digital Takeoffs
While manual quantity takeoffs are still widely in use, they are slowly falling out of favor due to the clear advantages of digital quantity takeoffs.
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, eliminating the need to perform complex calculations.
Secondly, digital takeoffs take much less time to produce, reducing labor costs associated with creating a quantity takeoff while also allowing the contractor to seek other opportunities and bid on 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, which frequently happens 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, allowing people that aren’t professional estimators to produce accurate and comprehensive construction quantity takeoffs in very little time.
Whether manual or digital, a quantity takeoff is still complex. The process for creating a quantity takeoff demands close attention to detail and thoroughness. However, digital takeoff software facilitates the production of quantity takeoffs by automating many more tedious aspects while also ensuring that takeoffs are accurate and produced in as little time as possible.