Construction projects require meticulous planning and accurate cost estimates to ensure they are completed on time and within budget. One crucial aspect of this process is calculating man-hours. Man-hours refer to the total amount of time that a worker or a group of workers will take to complete a specific task without any interruption. Accurate man-hour calculations are essential for estimating labor costs, managing resources, and ultimately delivering a successful construction project.
Let’s read how the construction cost estimators calculate man hours for a construction estimate.
Understanding Man-hours
Before delving into the process of calculating man-hours, it’s important to grasp the concept itself. A man-hour represents one hour of work performed by a single worker. For example, if a task takes 5 workers a total of 8 hours to complete, it would amount to 40 man-hours.
Let’s take a more detailed example:
Let’s assume you have a house of 2700 SF. You need to install sheetrock on walls and ceilings. The total SF are 33000 for complete walls and ceilings. On average, one drywall labor install 1600 SF of sheetrock per day and we have 6 laborers working on the job. Let’s calculate the total man hours.
1600/8 = 200 SF per hour for 1 labor.
6 Labors will do 200×6 = 1200 SF per hour.
Now calculate total number of man hours required to complete the job.
33000/1200 = 27.5 Man-Hours
Factors Affecting Man-hour Calculations
Several factors influence how man-hours are calculated for any type of construction project. These include:
1. Task Complexity:
Simple tasks may require fewer man-hours, while complex tasks can demand significantly more time. Complex tasks require expertise and the crew has to be extra careful while performing them. It affects the calculation of man hours as this is difficult to estimate the exact number of man hours.
2. Skill Level:
The expertise and experience of the workers assigned to a task can impact the time required. Highly skilled workers may complete tasks more efficiently while an apprentice takes more time to complete the same task. Skilled workers are also capable of delivering highest quality of work with timely completion.
3. Tools and Equipment:
From screw drivers to tower cranes, there are a number of tools and equipment used in construction process. The availability and efficiency of tools and equipment can either speed up or slow down the work process. While selecting the tools and equipment, you have to be very clear about the requirements as it can affect the budget and time frame of the project.
4. Environmental Conditions:
While calculating man hours, you have to predict the weather conditions. Adverse weather conditions, temperature extremes, or other environmental factors can affect productivity. There might be delays during construction so it should be taken into account while calculating man hours.
5. Site Conditions:
The location of the project also affect the labor productivity. Whether, it is in the center of a metropolitan or somewhere in the suburban, it impacts the calculation of man hours and overall project cost. Within city, you have to manage labor, get permits and check if there are any off hours. Every scenario should be considered while calculating man hours.
Steps to Calculate Man-hours
Step 1: Task Breakdown
Break down the entire project into smaller, manageable tasks. This will help you focus on individual components and assign the appropriate number of workers to each. For example, for a GC job, we have to breakdown it into all the trades like concrete, masonry, steel, sitework, MEP etc.
Step 2: Time Estimation per Task
Estimate the amount of time required to complete each task. This estimate should be based on previous data, industry standards, and the specific conditions of the project. An experienced contractor always have a good understanding about the requirements of the project. Considering those requirements, he can estimate the time for each trade.
Step 3: Determine Workforce Size
Based on the estimated time for each task, determine how many workers will be needed. Considering the above mentioned example, for a 33000 square feet of drywall, you will need 6 laborers for almost 3 and a half days. Always consider the skill levels and experience of the laborers, and any specific requirements for the task.
Step 4: Calculate Total Man-hours for Every Trade
During execution, the supervisor has to make sure that the labor achieve maximum productivity because it affects the overall budget of the project. To calculate total man hours, multiply the number of workers needed for each trade by the estimated time required to complete it. This will give you the total man-hours required for that trade.
Step 5: Account for Contingencies and Supervisor Cost
On every project, there has to be a supervisor responsible to take care of all the material on site and labor productivity. His fee should be taken into account. Also factor in allowances for unforeseen circumstances or delays. It’s advisable to add a contingency percentage to the total man-hours to account for potential issues. It should be 5%-10% of the total project.
Step 6: Sum Total Man-hours
Once we have the separate man hours for all the trades along with contingency. We need to add all of them to get the total man-hours needed for the entire project.
Utilizing an Estimating Company in Man-hour Calculations
To have all the above mentioned process streamlined, you need an expert estimating company who can help you save time and calculate the man hours on a specific project for you. Bidding Professionals LLC can help you calculate man hours and prepare a professional and organized bid as well. We have premium software and tools available that ensure accuracy and our team of expert estimators produce results.
Conclusion
Accurate man-hour calculations are a cornerstone of any successful construction project. They form the basis for estimating labor costs, managing resources, and ensuring that the project stays on schedule. Calculation of man-hours varies depending upon the structure, architecture, location and complexity of the project. Taking all of these factors under consideration, the estimator can make more precise estimates, leading to smoother and more efficient project execution. With the aid of modern technology, these calculations can be further refined, enabling construction teams to achieve higher levels of accuracy and productivity.
