Which item is typically the hardest to estimate on an installation project?

In the context of installation projects, labor is typically the hardest item to estimate due to several factors. Labor costs can be highly variable, influenced by the skill levels of workers, the complexity of the installation tasks, and the potential for unforeseen circumstances such as delays or changes in project scope.

Additionally, estimating labor requires accounting for different types of labor work, including skilled versus unskilled labor, and the varying rates associated with each. Factors like worker productivity, absenteeism, and overtime can further complicate accurate forecasting of labor costs, making them less predictable than material costs, rental equipment, or subcontractor costs.

While materials and rental equipment often have set costs that can be easily calculated, labor involves human elements that can change, leading to significant discrepancies from initial estimates. Similarly, subcontractor costs have contractual agreements that can provide more certainty in terms of expense than labor, where the actual hours worked could greatly alter the final cost versus what was initially planned. Thus, the variable nature of labor makes it harder to estimate accurately compared to other project costs.