To calculate cost estimates for a project, I measure its dimensions (in square feet) and multiply by the per-square-foot prices given below:
Estimates are guidelines for determining expected prices; billing is for actual costs of time and materials. Costs for individual projects can be affected by variables such as the particulars of the design and the site (such as its size, accessibility, and possible drainage issues), the distance of the site from my home, the amount of time spent in the design and planning phases, materials used, proximity to delicate plants or structures, weather conditions, and/or frequency of meetings and correspondence with clients or other collaborators.