Minimum Residential Requirements

Minimum Residential Code Requirements

Chapter 3 Sections 303 – of the 2015 International Residential Code lists many non-structural requirements that all structures intended for habitation must meet. These requirements include:

Light, Ventilation and Heating – Section R303


Lighting – All habitable rooms shall have window glazing to provide natural lighting that totals not less then 8% of the floor area of the room.

Ventilation – Natural ventilation shall be through windows, doors, louvers or other approved openings to the outdoor air. The minimum openable area shall be 4% of the floor area being ventilated.

Heating – Every dwelling unit shall be provided with heating facilities capable of maintaining a minimum room temperature of 680 F at a point 3 feet above the floor and 2 feet from the exterior wall of all habitable rooms.

Minimum Room Areas – Section R304

Every dwelling unit shall have at least one habitable room that is not smaller than 120 square feet of floor area. Other habitable rooms, except kitchens, shall have floor areas of not less than 70 square feet. All habitable rooms shall not be less than 7 feet in any horizontal dimension.

Ceiling Height – Section R305

Habitable rooms, hallways, bath and toilet rooms, laundry rooms, basements, etc. shall have a ceiling height of not less than 7 feet from the finished floor to the lowest projection from the ceiling. There is an exception for rooms with sloped ceilings requiring at least 50% of the minimum 70 square feet or 120 square feet floor area have ceiling height of at least 7 feet and no portion of the minimum floor area may have a ceiling height of less than 5 feet.

Sanitation – Section R306

All dwelling units must be provided with a kitchen area containing a sink and a bathroom containing a toilet, a sink and a bathtub or shower. All plumbing fixtures shall be connected to both approved water supplies and approved sanitary sewers or approved private sewage disposal systems. Kitchen sinks, bathroom sinks, bathtubs, showers, bidets, laundry tubs and washing machine outlets shall be provided with hot and cold running water.

Please refer to the 2015 IRC for the complete text of the above referenced sections and all other applicable code requirements.