Building code & frost-line guides by state

Every plan in our library specifies a 36-inch footing depth as the default. That is the IRC R403.1.4.1 baseline — but in roughly 18 of these 50 states, your local frost line is deeper than 36 inches and the default is not enough. In Maine, Minnesota, North Dakota, New Hampshire, and Vermont, the frost line reaches 60 inches. In coastal Louisiana, Mississippi, and most of Florida, you can dig as little as 6 inches and pass inspection — but you will face a 150-170 mph wind load that requires double hurricane ties at every rafter-to-beam connection.

Use the state guides below to look up the three pieces of information your local building inspector cares about: the minimum footing depth, the design wind speed, and the permit-exempt structure size. Then cross-reference them against any plan in our library.