The total project often spans $570 to $5,000, with per unit costs such as $2 to $15 per foot of fiber affected in some scenarios. Assumptions include standard single mode fiber, typical splice closures, and crew availability within common U S markets. The main cost drivers are materials, installation time, and environmental factors that affect trenching, conduit, and terminations. Commercial building installations with 100-200 network drops generally range from $15,000 to $30,000. You should account for permit. Costs to run fiber optic cable vary by distance, trenching needs, cable type and labor rates.