General Building Permit Code Requirements

Some of the more general building permit code requirements are:

• Light and ventilation – Including doors, windows, louvers, mechanical systems (HVAC), and other approved openings. In habitable rooms, window area must equal at least 8-percent of the floor space; at least half of the window area must be open able. Mechanical ventilation can replace operable windows. Bathrooms must ventilate to the outside with an intermittent rate of 5 cfm, and a continuous rate of 20 cfm. Bedrooms must supply outside air at a rate of 15 cfm for each occupant, primary bedrooms based on 2 occupants, additional bedrooms based on 1 occupant.
• Exits and openings – Habitable basements and bedrooms must have a minimum of 2 exits. One can be the entrance; the other must be an emergency door or egress window not requiring a tool or key to operate. Window openings must have a minimum height of 34-inches with a minimum width of 20-inches. Basement windows must have window wells; those deeper than 44-inches must also have steps, with additional requirements. All exits must operate from the inside with no special tools or knowledge.
• Room Proportions – Habitable rooms must have dimensions of at least 7X7 feet, with 7½-foot headroom; measurement is from the finished floor to lowest part of ceiling. Obstructions must be spaced at least 4-feet apart; no less than 7-foot headspace from the obstruction to the finished floor. For sloped ceilings, at least 50-percent of the total floor area must have 7 ½-foot ceilings; no part of the floor can have ceilings less than 5-feet from the finished floor. Kitchens should have at least 50 sq. ft. gross floor area; hallways must be at least 3-feet wide. At least one habitable room in the house requires a minimum of 120 sq. ft. floor space; other habitable rooms require a minimum of 70 sq. ft. floor space.
• Fire safety – Interconnected and concealed spaces such as soffits, stair stringers, ducts, drop and cove ceilings, fireplaces, chimneys, and areas around vents must be fire blocked to prevent fire spread. Perimeter (or exterior) walls are to be constructed on both sides to resist fire exposure for at least one hour. Note: a commonly used material for the interior side of these walls is 5/8-inch sheetrock. Approved batt or blanket insulation must be secured between studs and partitions. From ceiling to floor at a minimum of 10-inch intervals; vertically and horizontally. Other approved spray-on or loose insulation materials and wall coverings must meet flame and smoke spread ratings. Smoke alarms must be installed; at least one per floor, including one in each bedroom and bedroom hallway. Multiple alarms must be wired together to activate all alarms if one triggers.

While general building code requirements must be met for any project, there are stringent additional code requirements for specialized aspects of the project, such as electrical and plumbing.