A city cost index (CCI) is a measure used to compare the construction costs of residential projects in different cities. The CCI takes into account the differences in labor, materials, and other factors that can affect construction costs for a particular project when comparing one city to another. This measure enables contractors to better estimate and budget for their projects by understanding the varying costs associated with specific areas. Additionally, it provides an easy way for municipalities to assess how much they should charge for permits or fees related to projects within their boundaries.