APPENDIX AQ
TINY HOUSES
The provisions contained in this appendix are adopted for use statewide.
SECTION AQ101
GENERAL
AQ101.1 Scope.
This appendix shall be applicable to tiny houses used as single dwelling units. Tiny houses shall comply with this code except as otherwise stated in this appendix.
SECTION AQ102
DEFINITIONS
AQ102.1 General.
The following words and terms shall, for the purposes of this appendix, have the meanings shown herein. Refer to Chapter 2 of this code for general definitions.
EGRESS ROOF ACCESS WINDOW. A skylight or roof window designed and installed to satisfy the emergency escape and rescue opening requirements of Section R310.2.
LANDING PLATFORM. A landing provided as the top step of a stairway accessing a loft.
LOFT. A floor level located more than 30 inches (762 mm) above the main floor, open to the main floor on one or more sides with a ceiling height of less than 6 feet 8 inches (2032 mm) and used as a living or sleeping space.
TINY HOUSE. A dwelling that is 400 square feet (37 m2) or less in floor area excluding lofts.
SECTION AQ103
CEILING HEIGHT
AQ103.1 Minimum ceiling height.
Habitable space and hallways in tiny houses shall have a ceiling height of not less than 6 feet 8 inches (2032 mm). Bathrooms, toilet rooms and kitchens shall have a ceiling height of not less than 6 feet 4 inches (1930 mm). Obstructions including, but not limited to, beams, girders, ducts and lighting, shall not extend below these minimum ceiling heights.
Exception: Ceiling heights in lofts are permitted to be less than 6 feet 8 inches (2032 mm).
SECTION AQ104
LOFTS
AQ104.1 Minimum loft area and dimensions.
Lofts used as a sleeping or living space shall meet the minimum area and dimension requirements of Sections AQ104.1.1 through AQ104.1.3.
AQ104.1.1 Minimum area.
Lofts shall have a floor area of not less than 35 square feet (3.25 m2).
AQ104.1.2 Minimum horizontal dimensions.
Lofts shall be not less than 5 feet (1524 mm) in any horizontal dimension.
AQ104.1.3 Height effect on loft area.
Portions of a loft with a sloped ceiling measuring less than 3 feet (914 mm) from the finished floor to the finished ceiling shall not be considered as contributing to the minimum required area for the loft. See Figure AQ104.1.3.
Exception: Under gable roofs with a minimum slope of 6 units vertical in 12 units horizontal (50-percent slope), portions of a loft with a sloped ceiling measuring less than 16 inches (406 mm) from the finished floor to the finished ceiling shall not be considered as contributing to the minimum required area for the loft.
For SI: 1 foot = 304.8 mm.
FIGURE AQ104.1.3
HEIGHT EFFECT ON LOFT AREA
AQ104.2 Loft access and egress.
The access to and primary egress from lofts shall be of any type described in Sections AQ104.2.1 through AQ104.2.5. The loft access and egress element along its required minimum width shall meet the loft where its ceiling height is not less than 3 feet (914 mm).
AQ104.2.1 Stairways.
Stairways accessing lofts shall comply with this code or with Sections AQ104.2.1.1 through AQ104.2.1.7.
AQ104.2.1.1 Width.
Stairways accessing a loft shall not be less than 17 inches (432 mm) in clear width at or above the handrail. The width below the handrail shall be not less than 20 inches (508 mm).
AQ104.2.1.2 Headroom.
The headroom above stairways accessing a loft shall be not less than 6 feet 2 inches (1880 mm), as measured vertically, from a sloped line connecting the tread, landing or landing platform nosings in the center of their width and vertically from the landing platform along the center of its width.
AQ104.2.1.3 Treads and risers.
Risers for stairs accessing a loft shall be not less than 7 inches (178 mm) and not more than 12 inches (305 mm) in height. Tread depth and riser height shall be calculated in accordance with one of the following formulas:
1. The tread depth shall be 20 inches (508 mm) minus four-thirds of the riser height.
2. The riser height shall be 15 inches (381 mm) minus three-fourths of the tread depth.
AQ104.2.1.5 Landing platforms.
The top tread and riser of stairways accessing lofts shall be constructed as a landing platform where the loft ceiling height is less than 6 feet 2 inches (1880 mm) where the stairway meets the loft. The landing platform shall be not less than 20 inches (508 mm) in width and in depth measured horizontally from and perpendicular to the nosing of the landing platform. The landing platform riser height to the loft floor shall be not less than 16 inches (406 mm) and not greater than 18 inches (457 mm).
AQ104.2.2.1 Size and capacity.
Ladders accessing lofts shall have a rung width of not less than 12 inches (305 mm), and 10-inch (254 mm) to 14-inch (356 mm) spacing between rungs. Ladders shall be capable of supporting a 300-pound (136 kg) load on any rung. Rung spacing shall be uniform within 3/8 inch (9.5 mm).
AQ104.2.2.2 Incline.
Ladders shall be installed at 70 to 80 degrees from horizontal.
SECTION AQ105
EMERGENCY ESCAPE AND RESCUE OPENINGS
AQ105.1 General.
Tiny houses shall meet the requirements of Section R310 for emergency escape and rescue openings.
Exception: Egress roof access windows in lofts used as sleeping rooms shall be deemed to meet the requirements of Section R310 where installed such that the bottom of the opening is not more than 44 inches (1118 mm) above the loft floor, provided the egress roof access window complies with the minimum opening area requirements of Section R310.2.1.
SECTION AQ106
ENERGY CONSERVATION
AQ106.1 Air leakage testing.
The air leakage rate for tiny houses shall not exceed 0.30 cubic feet per minute at 50 Pascals of pressure per square foot of the dwelling unit enclosure area. The air leakage testing shall be in accordance with the testing methods required in Section N1102.4.1.2. The dwelling unit enclosure area shall be the sum of the areas of ceilings, floors and walls that separate the conditioned space of a dwelling unit from the exterior, its adjacent unconditioned spaces and adjacent dwelling units.
AQ106.2 Alternative compliance.
Tiny houses shall be deemed to be in compliance with Chapter 11 of this code and Chapter R4 of the International Energy Conservation Code, provided that the following conditions are met:
1. The insulation and fenestration meet the requirements of Table N1102.1.2.
2. The thermal envelope meets the requirements of Section N1102.4.1.1 and Table N1102.4.1.1.
3. Solar, wind or other renewable energy sourcesupplies not less than 90 percent of the energy use forthe structure.
4. Solar, wind or other renewable energy sourcesupplies not less than 90 percent of the energy forservice water heating.
5. Permanently installed lighting is in accordance withSection N1104.
6. Mechanical ventilation is provided in accordance with Section M1505 and operable fenestration is not used to meet ventilation requirements.