Water and Sewer - If your building site has water and sewer available it will cost less than if you have to drill a well or install a septic system. A sand mound for a septic system could cost upwards of $25,000 alone.
Rock and Cliffs - Once your excavation is started, and rock is hit, the cost to blast it away could cost thousands of dollars in additional construction costs.
Fill - Your building site could require fill to hauled in or hauled out. This additional cost could drive the price of your modular home through the ceiling.
Access - A building site that requires a hundred foot driveway will cost five times or more compared to a twenty foot driveway. A long driveway will drive up the total price of your modular home.
Clearing Requirements - The cost to cut trees down could be the difference between hardwood flooring and vinyl flooring.
Slope - A super steep slope will cost thousands of dollars to ready the home for your home.