When it comes to multifamily construction, sitework is often the most variable cost. Estimating sitework can be particularly challenging in the conceptual phase when all you have is a plan of existing conditions and an idea of what the project could be. However, with careful planning and accurate calculations, estimating sitework can become more manageable.
In this post, we’ll explore tips on how to estimate sitework effectively.
Understanding Sitework
Before diving into the estimation process, it’s essential to understand what sitework entails. Sitework refers to the preparation of the construction site before actual construction can begin. This includes excavating, grading, and installing utilities such as water, gas, and electric lines. Sitework can also involve the construction of access roads and parking lots.
Calculating Work Quantities
The first step in estimating sitework is to calculate the work quantities. This involves taking off quantities from engineering drawings, such as site plans, utility plans, and grading plans. Once you have identified the work items, you can calculate the quantity of each item required for the project. This could include the number of yards of concrete for the foundation, the number of feet of waterline, or the amount of backfill required.
Adjusting for Material Swell and Shrink
When estimating sitework, it’s essential to account for material swell and shrink. Material swell is the increase in volume that occurs when soil is excavated, while shrink is the decrease in volume when the same soil is compacted. Failing to adjust for material swell and shrink can lead to inaccurate cost estimates. Typically, a swell factor of 10-15% and a shrink factor of 15-20% are used in sitework estimation.
If the amount of material needed for a project is underestimated due to material swell, for example, the project may run out of material mid-construction, causing costly delays and even requiring the purchase of additional materials. By factoring in material swell and shrink, estimators can ensure that their projections are as accurate and reliable as possible, minimizing the risk of unexpected costs and delays.
Assembling Efficient Crews
To estimate sitework effectively, you need to assemble an efficient crew. This requires an understanding of the skill sets required for each task and the number of workers needed. It’s also essential to consider the productivity of the crew, including their experience, work ethic, and equipment proficiency. Using experienced and efficient crews can help reduce labor costs and increase productivity.
Determining Productivity
Determining productivity is a crucial factor in estimating sitework. Productivity can be impacted by several factors, including weather conditions, equipment availability, and material delivery schedules. To estimate productivity accurately, you must consider the impact of these factors and adjust the estimates accordingly. This will help ensure that the estimated work schedule is realistic and achievable.
Faqs
What is sitework?
A: Sitework refers to the preparation of the construction site before actual construction can begin. This includes excavating, grading, and installing utilities such as water, gas, and electric lines.
How do you calculate work quantities for sitework?
A: You can calculate work quantities by taking off quantities from engineering drawings, such as site plans, utility plans, and grading plans.
What is material swell and shrink, and why is it important to account for it in sitework estimation?
A: Material swell and shrink refer to the natural tendency of certain materials to expand or contract when they are excavated, moved, or compacted. For example, soil may expand or “swell” when it is dug up, but then contract or “shrink” when it is recompacted. This can significantly impact the amount of material that is needed for a project and, therefore, its cost.
Conclusion
Sitework Estimating is a critical component of multifamily construction. By following the tips and strategies outlined in this post, you can increase the accuracy of your sitework cost projections, minimize unexpected expenses, and ensure the success of your project. Remember that sitework estimation is a continual process that requires constant reevaluation and adjustment throughout the construction process. By staying vigilant and adapting to changes as they arise, you can ensure the timely and cost-effective completion of your project.
