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What International Residential Code (IRC) 2018 Means for Tiny Home Building

As Jim Greer, Clayton’s National Brand Manager of Tiny Homes, leads Clayton into the microliving movement, he continues to meet with state leaders and tiny home movement influencers to discuss the rapidly evolving housing industry. Greer and other key tiny home players are excited about the IRC 2018 update which includes .


What Does IRC 2018 Appendix Q Say?

Clayton Low Country Tiny Home Kitchen

Low Country tiny home 


Appendix Q of the IRC states that tiny houses built as small modular homes shall comply with IRC code in those states that adopt Appendix Q as part of their building code.  


Not only is the new inclusion of tiny homes in the IRC exciting, there are also specific, notable allowances that Appendix Q outlines for tiny houses, such as allowances for lofts and ladders. It also defines tiny houses as being 400 square feet or less in floor area excluding lofts. The appendix outlines safety guidelines as well such as tiny home emergency escape requirements.


Reasons for the IRC Tiny House Appendix

Clayton Saltbox Bathroom

Saltbox tiny home


The tiny house appendix came as a result of a Public Comment submitted to the IRC committee on the basis of environmental and financial concern. The submission argued that tiny houses can help not only minimize the environmental impacts of American housing, but also provide safe homes at affordable prices.


However, to ensure the safety of these tiny homes as the tiny movement grows, tiny house builders would need a set of building regulations to follow and enforce.


The submission entailed reasons to embrace tiny home building such as:

  • The average U.S. home size increase of 61% since 1973.
  • The average U.S. home size use of building materials compared to that of a tiny house.
  • The low national homeownership rate as a result of rising housing costs.
  • The amount of money that the average American spends on housing.


Appendix Q was added to the IRC, but it does not become part of a state’s IRC building code unless the states also adopt Appendix Q. It’s important to keep in mind that the appendix is only applicable when specifically adopted by the local, applicable building authority. Some states have a separate building authority for certain types of housing.



How Appendix Q Affects Designer Series Tiny Homes

Clayton Tiny Home Shower

Low Country tiny home


This code update potentially gives tiny home buyers and builders flexibility. Designer Series tiny homes are already built as modular homes which means the tiny homes are built to all applicable state and local building codes. Forty-nine states in the U.S. have adopted some version of the IRC, so as states adopt new Appendix Q of the IRC, tiny home builders may have more freedom with tiny homes. For instance, Designer Series tiny homes could include ladders and lofts in states that adopt IRC 2018 Appendix Q.


Regardless of which states adopt varying versions of IRC, because of the nature of modular home building, Designer Series tiny homes will still be designed and constructed to each specific state’s applicable building requirements for modular homes.


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