Appendix Q: 2018 Residential Code

First Printing August 2017

Provisions Contained In This Appendix Are Not Mandatory Unless Specifically Referenced In The Adopting Reference

It Is Up To Each Municipality And State To Adopt Appendix Q Into

Its Residential Building Code.

This Page Will Be A Work In Progress As Municipalities And States Are Added

Tiny Houses On A Foundation: 400 Square Feet Or Less

Written by Janet Thome

Appendix Q Tiny Houses was approved for inclusion to the 2018 International Residential Code ( IRC ) building code to provide regulations and standards for tiny houses on a foundation that is 400 square feet or less.

Appendix Q relaxes various requirements in the body of the code as they apply to tiny houses that are 400 square feet or less. Attention is specifically paid to features such as compact stairs, including handrails and headroom, ladders, reduced ceiling heights in lofts and guard and emergency escape and rescue opening requirements of lofts.

The International Residential Code is a comprehensive, stand-alone residential code that creates minimum regulations for one-and two-family dwellings of three stories or less.

The IRC brings together all building, plumbing, mechanical, fuel, gas, energy, and electrical for provisions for one-and two-family residences.  Appendix Q was adopted to the IRC building code standards through the ICC Code Development Process.

Jurisdictions may use Appendix Q as a model code to adopt, reference, or amend. Builders or even jurisdictions that have not adopted the 2018 IRC or the Appendix, can seek approval ”on a project basis through the alternative materials and designs provision” in the IRC.-David Eisenberg, co-author of The Strawbale House Book.

ICC Code Development Process

Adoption of the IRC

The International Residential Code (IRC) is in use or adopted in 49 states, the District of Columbia, Guam, Puerto Rico, and the U.S. Virgin Islands. Wisconsin is the only state not applicable to IRC building codes. In Alaska, the IRC is not adopted statewide. The “Deferred Cities” can adopt additional codes and some jurisdictions adopt the IRC and the IECC.

As a model code, the IRC is intended to be adopted in accordance with the laws and procedures of a governmental jurisdiction. When adopting a model code like the IRC, some jurisdictions amend the code in the process to reflect local practices and laws.


Appendix Q is applicable to tiny houses used as single dwelling units. Tiny homes shall comply with this code unless otherwise stated.

Appendix Q

From The ICC Learning Center 2018 IRC Update

ICC:  ANSI Standard Developer

ICC, the International Code Council, an ANSI Standard Developer ( ASD) is a nonprofit organization that develops and publishes standards related to building safety and fire prevention. Headquartered in Washington, D.C., United States, ICC standards have been codified and enforced in all 50 American states, as well as in various foreign countries. With nearly 340 chapters worldwide, each with many members, ICC building safety standards are used everywhere.

Goal Of ICC


Utilize a process open to all parties with safeguards to avoid domination by proprietary interests. ICC Governmental Consensus Process achieves this with the final vote resting with those administering, formulating or enforcing regulations relating to public health, safety, and welfare

The International Code Council develops construction and public safety codes through a governmental consensus process. This system of code development has provided the highest level of safety in the world for more than 90 years. The ICC governmental consensus process meets the principles defined by the National Standards Strategy of 2000, and the OMB Circular A-119, Federal Participation in the Development and Use of Voluntary Consensus Standards and in Conformity Assessment Activities (1998). It complies with Public Law 104-113 National Technology Transfer and Advancement Act of 1995. The following principles are adhered to in ICC’s governmental consensus process:

  • Openness
  • Transparency
  • Balance of Interest
  • Due Process
  • Appeals Process
  • Consensus

The International Codes

  • Are innovative and coordinated.
  • Cannot be influenced by vested financial interests.
  • Are efficient and effective.
  • Are developed through the efforts of public safety officials.
  • Are up to date and state of the art.
  • Are updated every three years.
  • Are economically viable and practical.

The Benefits of Participating in the Code Development Process

Imagine a world where you can shape the regulations that ensure the health, safety, and welfare of the people who live in, work in and visit the community you serve.

Governmental Consensus Process

The governmental consensus process leaves the final determination of code provisions in the hands of public safety officials who, with no vested financial interest, can legitimately represent the public interest.

ICC Code Development Process

Code Addition Every Three Years

Upcoming Version: 2021 IRC Development

The International Residential Code provisions provide many benefits, among which is the model code development process that offers an international forum for residential construction professionals to discuss prescriptive code requirements. This forum provides an excellent arena to debate proposed revisions.

The International Residential Code has a Big Vision for Tiny Houses February 1st, 2018

Appendix Q Tiny House is the first set of building standards for dwellings ever incorporated into a model code. The story of how the appendix came to be is a great example of how the Code Council works together with stakeholders and industry professionals to develop model code standards for new and innovative technologies as they emerge.

At the hearing, however, one person had testified in “friendly opposition” to the proposal: Martin Hammer, an architect who had co-authored the IRC’s straw-bale construction appendix. Following the hearing, Hammer received a call from his friend Andrew Morrison of, a builder and educator who had helped Hammer write the appendix. “Andrew asked if I thought we could submit a different proposal,” Hammer recalled.

Tiny-house advocates across the country reviewed the draft language and donated funds to pay for Hammer’s time as a consultant and to help Morrison and others travel to Kansas City to attend the public hearings. Morrison also received helpful feedback from the International Code Council, which he incorporated into the draft.

Article Source ICC Building Safety Journal

Special Thanks To David Eisenberg

”My main role was in working with the proponents in strategizing and preparing for testimony at the Public Comment Hearing, as well as testifying there, and then helping strategize and develop outreach materials for the online national vote that followed our success at the hearing.”

Together, Martin and I brought to the tiny house community our years of experience in developing code change proposals for alternative materials and systems and our relationships with the codes community. ” ”We were able to offer practical guidance on the code development and code change processes, and how best to work with that system and code officials from around the country who make the final decisions about what goes into the codes.”

David Eisenberg

About David Eisenberg

David Eisenberg is co-founder and Director of the Development Center for Appropriate Technology (DCAT) in Tucson, AZ. His three decades of building experience range from the on-site troubleshooting of the construction of the cover of Biosphere 2 to building a $2 million structural concrete house, a hypoallergenic structural steel house, and masonry, wood, adobe, rammed earth, and straw bale structures. For over a decade David has led the effort to create a sustainable context for building codes. He served two terms on the Board of the U.S. Green Building Council where he founded and chairs the Building Codes Committee. He was vice-chair of the ASTM E-06.71 Subcommittee on Sustainability for Buildings for five years. David has presented workshops, seminars, keynote addresses, and lectures at dozens of international, national, and regional conferences and lectured at universities in the U.S. and abroad. David is on the Advisory Board of Environmental Building News. He is co-author of The Straw Bale House book and has written dozens of published articles, forewords, book chapters, and papers.

Development Center For Appropriate Technology ( DCAT )

ICC Podcast: Episode Nine

Scroll Down To Episode Nine

List Of Municipality Or State That Has Adopted Appendix Q

Alaska: In Alaska, the IRC is not adopted statewide. The “Deferred Cities” can adopt additional codes and some jurisdictions adopt the IRC and the IECC.

The IBC, IFC, IMC in Alaska are adopted by administrative rulemaking by the Alaska State Fire Marshal. The adopted code by state agencies are mandatory and falls under state inspection programs unless a local jurisdiction has been delegated by the code program as a “deferred jurisdiction.” When this occurs, the local jurisdiction administers and enforces its local program of the adopted state codes.

State Fire Marshall Of Alaska Richard Boothby

Deferred Jurisdictions

Tiny Houses In Juneau

Juneau, Alaska has NOT adopted Appendix Q at this time, however, they are usually it as a Guide for residents to build tiny homes on a foundation. I spoke with a few officials and it will take years for any new code changes. August 1st, 2019.

Tiny Homes on mobile chassis will be allowed in certain situations. Please contact the CDD for more information at 907 586 0715.

Juneau, Alaska

Sitka, Alaska

Tonight, The City and Borough of Sitka, Alaska creates history for the tiny home industry. The second and final reading for ORD 20-02S (A) passed at a vote 6 to 0 and is a great win for movable tiny homes. Sitka, Alaska has approved tiny homes on a foundation, but what is groundbreaking, they have written an ordinance that amends Appendix Q that applies to movable tiny homes. From the floor joists up, the tiny home will be built to the IRC Appendix Q.

Groundbreaking Sitka, Alaska Tiny House Ordinance


Note: Arizona is one of the friendliest states in the country regarding tiny homes, including tiny homes on wheels. I will be including information for tiny homes on wheels and park models, even if Appendix Q has not been adopted as helpful information.

Phoenix: Adopted   Effective  July 6th, 2018 

Elizabeth Singleton, CEO of Tiny House Builders advocated for the adoption of Appendix Q in Phoenix and is working on the approval process for movable tiny homes in Phoenix, applying Appendix Q to movable tiny homes.

Cave Creek Adopted  2018 IRC- Adopted January 1st, 2019

Sedona  Spoke With Steve Mertes on July 29th, 2019 – Appended Q is in the works and will be adopted in the next few months- I will be following up with Steve

Building Code Update

Tuscon  Adopted 2018 IRC- Adopted Appendix Q

Camp Verde: On Oct. 24, 2018, the Camp Verde Town Council approved an agri-tourism use permit for a community of tiny houses on wheels, vintage recreational vehicles, and agri-tourism events. The 15-acre parcel that would house the complex is owned by Camp Verde residents Carmen Howard and her husband David.

Article SourceTinyPortableCedarCabins 

Coconino County Adopted 4/4/2019

The Town Of Edgar Adopted 4/2/2019

Flagstaff   Adopted 2018 IRC and Appendix Q With ConditionsEffective July 19, 2018 

City Of Flagstaff


Pima County

Apache County: Apache County – 2015 Residential Building Code: Appendix Q Not Adopted

Apache County Building Safety Division

Yavapai County: Effective July 1st, 2019: For Unincorporated Areas Of Yavapai County

Yavapai County

Park Models
A Park Model is allowed as a Dwelling Unit per Section 565 of the Yavapai County Planning and Zoning Ordinance. A permit is required prior to installation of a Park Model Unit

Development Services Yavapai County

California: Mandatory Across All Local Government Jurisdictions:

Effective January 1st, 2020

California Building Code Update (6/17/2019) – Appendix Q Tiny Houses: In recent discussions and emails with key staff of CA Department of Housing and Community Development (HCD), we have confirmed the following:
1) HCD has adopted the provisions of Appendix Q which will make its provisions MANDATORY across all local government jurisdictions.
2) We were able to confirm with HCD, that factory-built housing (FBH) next year can be built to CA Residential Code standards, inclusive of Appendix Q, (for units 400 sq. ft. or less).
3) Such FBH units built using Appendix Q standards would be permitted anywhere is California, subject of course to zoning codes.
4) The California building code update will go into effect on January 1, 2020.


For the past several months we have been quietly working with the California Department of Housing and Community Development (HCD) and the Governor’s Office of Planning and Research (OPR) to ensure that provisions of the 2018 International Residential Code, including our tiny house Appendix Q code provisions, were properly implemented into the California Residential Code. Our concern was that we wanted Appendix Q code items for tiny homes to be, not only adopted by the state but made MANDATORY in all of the 540 local government jurisdictions.

In past California code update cycles, the various Appendices were left as a local option. Why is this important? One can only imagine the effort it would take to convince 540 cities and counties to adopt Appendix Q – a task that would take years to accomplish. Also, if Appendix Q provisions were not adopted across the board for all of California, it would be virtually impossible to factory-build tiny house units for wide distribution.


Special Shout Out To Martin Hammer

A special shout out to Martin Hammer for, not only his work with Andrew Morrison in writing Appendix Q but his efforts to stay on top of state bureaucrats to implement it properly in California.

Source: Dan Fitzpatrick, Director of Government Relations and Advocacy for ATHA

Article Source


Archuleta County: August 28th, 2019 Spoke to planner John Shepherd

Colorado Appendix Q News: Archuleta County Public Meeting Of The Commissioners Adopting 2015 and Appendix Q: Public Welcome Sept 5th,
2019 at 8:30 Am at Archuleta County Administration Office
398 Lewis St, Pagosa Springs, CO 81147
Details Call Mary 907 264 8308 / They welcome written comments before the meeting; Send to


Boulder Approves Appendix Q At City Council Meeting Jan. 21st, 2020

Boulder is considering adopting Appendix Q. The first reading was Nov 19th, 2019: Second Reading Jan. 21st,  2019  Public Hearing

Ms. Thome,

Thank you for emailing City Council regarding Appendix Q Tiny Homes.  This item is scheduled for first reading on tonight’s Consent Agenda and the second reading and public hearing is scheduled for Jan. 21st, 2019  The current ordinance for consideration includes the adoption of Appendix Q Tiny Homes which incorporates building standards for small homes, maximum 400 square feet.  Staff have proposed two amendments to Appendix Q, explicitly requiring the homes to be installed on permanent foundations and be permanently connected to utilities.

Comments are always welcome during public hearings.  You may email your comments directly to City Council.

City council of Boulder

Will Birchfield

Building Services Manager/Chief Building Official


Denver Adopts Appendix Q: Effective Dec. 26th, 2020 With A Transition Period For Builders Until April 26th, 2020

Denver: Public Forum: Code Discussion Including Appendix Q Nov. 5th, 2019

Denver Code Development Changes Including Appendix Q For Tiny Homes from Nov 5th courtesy briefing

Denver Gov

Article Source Denver Development Services

Article Source City Of Denver

La Playta County: Effective January 2018

La Playta County

Routt County

Routt County

Town Of Lyons

The Town of Lyons


Confirmed on Sept 24th, 2019 from Joseph V. Cassidy P.E. State Building Inspector- They are considering the adoption of Appendix Q as part of our 2020 State Building Code. They are in the technical development portion of our process now.  There will be a public comment period for the completed draft code early next year.

Follow the process

Anyone interested in receiving informational and update emails may request to be included on our email list by sending a request to

Florida Adopts Appendix Q: Effective Date Dec. 31st, 2020

Appendix Q has been included in the Florida Building Code, 7th Edition (2020), Residential, which will be effective December 31, 2020.  You can view Appendix Q as part of the Florida Building Code, 7th Edition (2020), Residential, at this link:

Florida 2020 Building Codes.

Florida: Status Appendix Q- Reserved: Spoke to the building dept August 28th, 2019 Modification # F7942

Florida In Progress To Adopt Appendix Q Tiny Homes: Deadline Jan. 2nd, 2020

Article Source Florida Dept of business

Georgia: Effective Jan 1st, 2020: 2018 IRC And Appendix Q

The  2012 IRC has been amended to change the minimum habitable room size from 120 sf to 70 sf and add a new Appendix for Tiny House Construction. However, the Appendix must be adopted locally to be enforced.

Appendix Q has already been adopted: Referred  to as Appendix S until their code cycle change in 2020

Codes Update Spring 2019

Tiny House Information

Map Of Jurisdiction


Hawaii Meeting Tomorrow At 9 am: 2018 IBC And IRC Editions Including Appendix Q Tiny Homes: Dec 16th, 2019 STATE OF HAWAII

P.O. BOX 119, HONOLULU, HAWAII 96810-0119
State Building Code Council (SBCC) Meeting
Tuesday, December 17, 2019
9:00 a.m.
Department of Accounting and General Services
Comptroller’s Conference Room 410
Kalanimoku Building
1151 Punchbowl Street
Honolulu, Hawaii 96813
West Hawaii Civic Center
Building “E”, First Floor
74-5044 Ane Keohokalole Highway
Kailua-Kona, Hawaii 96740
Telephone Call-In

240-454-0879 Access Code 939103

SBCC Agenda 12-17-19

Hawaii is using the 2018 IRC: They have not adopted Appendix Q at this time-we have sent them information so they can start the discussion. Spoke to Howard Wiig on Sept.17th, 2019

Howard Wiig 808 587 3811

Idaho: First State To Adopt Appendix Q:  Added to 2012 IRC Code 3/20/17

Article Source Idaho.Gov

Boise: IRC  Building Code Amendment, Add Appendix V, Tiny Homes Jan. 1st, 2018

Add an additional appendix titled Appendix V Tiny Homes into the code with sections and provisions as follows:

City Of Boise

Moscow: Passed By The City Council And Signed Mayor Bill Lambert June 3rd, 2019



City Of Moscow Tiny Homes

Indiana: Amended And Adopted Statewide, All Jurisdictions  Effective Date Dec. 31st, 2019

Indiana Amended Appendix Q Tiny House

Indiana 2020 Residential Code

Illinois: Received Email After Inquiring On Sept 24th, 2019

Currently, the Office of the State Fire Marshal does not have any regulations regarding tiny homes unless they are used as daycare homes or some other state-licensed facility. In Illinois you need to go to individual municipalities to see what their requirements might be. Illinois does have a statewide building code, but it is only a default building code used for those areas that do not have a building code. That would be the 2006 or later edition of the International Building Code/International Residential Code. So you will need to determine which municipalities are using their own adoption or are using the default IBC/IRC adoption. I am not sure if the IBC/IRC has adopted language regarding tiny houses (a colleague I am with today does not believe so).

Cathy Stashak, Section Chief
Technical Services Division

Yorkville, Illinois: Effective Jan 1st, 2020

Confirmed On Oct 1st, 2019 through email from Pete Ratos
Pete Ratos
United City Of Yorkville
Building Code Official

City Of Yorkville 


Manhattan, Kansas Effective January 1st, 2020 

Article Source City Of Manhattan

Riley County July 28h, 2019- Need to do further investigation 

Riley County requires a permit but does not enforce building codes. The inspector does inspect how a home is being inspected.

Article Source Riley County Gov

Sedgwick County/City of Wichita, Kansas August 21st, 2018
18 Smaller Cities and 2 adjacent Counties

Article Source Wichita.Gov

Kentucky: State Mandated Amended Version And Defining Appendix Q Effective Jan 2019

Kentucky specific amendments are below:

2018 Kentucky Residential Code, Second Edition

HBC enforces statewide standards for building construction. The agency ensures fire and life safety in existing buildings; licenses/certifies plumbers, electricians, boiler contractors, sprinkler and/or fire alarm contractors, and building inspectors.  The main DHBC phone number is 502-573-0365

Department of Housing, Buildings, and Construction 

Louisiana: Adopted December 20th, 2018

Amended current  Rule to add the 2018 International Residential Code ( IRC ) Appendix Q Tiny Homes to the Uniform Construction Code. The Rule allows for inspection and permitting of said homes in any jurisdiction of the state.

Article Source Louisiana Gov News

Article Source Louisiana Gov News


Article Source Maine Public

Tiny Home City Council Workshop

Maryland Statewide: Adopted Statewide Left Up To Local Jurisdiction

Article Source Maryland Dept. Of Labor

Massachusetts: Effective  January 2020

The newest complete edition of the MA Building Code will be released in 2021.  However, effective 1/1/2020, Appendix Q, also known as the Tiny House Appendix, is anticipated to be adopted into the current Massachusetts state building code.

Article Source BBTinyHome News

House Bill 2031

Mass Gov

Michigan: Appendix Q Is A Selected Option In ”Select IRC Options Use With The Michigan Residential Code”

The Home Builders Association of Michigan (HBAM) and the International Code Council (ICC) have joined forces to publish a targeted book of changes in the 2018 IRC to allow Home Builders Association of Michigan members and others to benefit from their new ability without having to buy the entire code. The book is titled ” 2018 Select IRC Options For Use With The Michigan Residential Code.”

Michigan Is Staying With 2015 IRC Until 2021 Is Adopted

The Flex Code Law, Public Act 504 of 2012 allows Michigan to choose to update the Michigan Residential Code every three or six years. Michigan chose not to update to the 2018 edition of the IRC published by the ICC and will be staying with the 2015 MRC until the 2021 edition of IRC is available and adopted.

Article Source Tiny Home Industry Association


2020 Statewide Construction Codes Includes Appendix Q


Camdenton  Adopted 2018 IRC And Appendix Q

Green City:

Spoke with Joel Binkley on July 31st, 2019. He said they will probably follow Springfield’s lead and Adopt Appendix Q.


Spoke to Ime Usukumah on  July 31st, 2019. He confirmed that they are adopting Appendix Q by the end of the year.


Update on Nov. 29th, 2019. Montana has adopted Appendix Q. Effective date Dec.7th, 2019. Appendix Q has been adopted in its entirety. Jurisdictions have the choice to adopt locally.

(a) Appendix Q, Tiny Houses. Appendix Q may be adopted by a certified city, county, or town building code jurisdiction. Tiny houses do not meet the building code requirements for commercial or business occupancy and are therefore prohibited for these types of uses. The department will apply Appendix Q to factory-built buildings which meet the definition of a tiny house as having 400 square feet or less in floor area excluding lofts, and which are intended to be mounted on a permanent foundation and used as a single-family dwelling.

Note: I spoke to Tim Lloyd again on Nov. 29th and he clarified the terms regarding commercial. Long term rentals are allowed, they just do not want nightly rentals like an AirBnB.

State Of Montana: Department Of Labor And Industries

Spoke to Tim Lloyd: Last day of public comment is Sept.20th, 2019: Tim said they were planning to adopt and did not see much opposition

Send comments

(a) Appendix Q, Tiny Houses. Appendix Q may be adopted by a certified city, county, or town building code jurisdiction. Tiny houses do not meet the building code requirements for commercial or business occupancy and are therefore prohibited for these types of uses. The department will apply Appendix Q to factory-built buildings which meet the definition of a tiny house as having 400 square feet or less in floor area excluding lofts, and which are intended to be mounted on a permanent foundation and used as a single-family dwelling.

Building Code Documents


Nebraska: 2018 IRC-The State Does Not Normally Adopt Appendixes That Is Up To The Local Jurisdictions

State building code; adopted; amendments.

(1) There is hereby created the state building code. The Legislature hereby adopts by reference:

(a) The International Building Code (IBC), chapter 13 of the 2018 edition, and all but such chapter of the 2018 edition, published by the International Code Council, except that (i) section 305.2.3 applies to a facility having twelve or fewer children and (ii) section 310.4.1 applies to a care facility for twelve or fewer persons;

(b) The International Residential Code (IRC), chapter 11 of the 2018 edition, and all but such chapter of the 2018 edition except section R313, published by the International Code Council; and

(c) The International Existing Building Code, 2018 edition, published by the International Code Council.

(2) The codes adopted by reference in subsection (1) of this section and the minimum standards for radon-resistant new construction adopted under section 76-3504 shall constitute the state building code except as amended pursuant to the Building Construction Act or as otherwise authorized by state law.

Nebraska Legislature

Omaha, Nebraska Has Adopted Appendix Q Tiny House

Sec. 43-121. – Building codes adopted

Appendix Q, “Tiny Houses“, of the International Residential Code, 2018 edition

Municode Omaha, Nebraska

New Jersey: Effective Sept. 3rd, 2019

New Jersey

New Jersey Gov

New Hampshire: New Bill To Study Tiny Homes: Effective November 1st, 2019

New Hampshire Established A Bill To Study Tiny Houses: Effective November 1st, 2019: House Bill 312

Those issues include defining the very structures themselves: “The committee shall determine what constitutes a ‘tiny house,’ both on a permanent foundation and on wheels.”
Proponents of tiny homes say they can expand the state’s housing options by providing a relatively low-cost place to live that might help ease labor shortages and keep young adults in the state.

Article Source Legal Scan

New Mexico: Effective January 15th, 2018

Article Source New Mexico Register

New Tiny Home Ordinance: Roswell

New York: Adopting 2018 IRC Including Appendix Q Estimated Effective Date March 2020

2020 Residential Code of New York State

Building Code Standards of New York State

Public Comments Until September 10th, 2019

If you have suggestions on how the proposed rule amending the Uniform Code could be improved, suggested alternatives the proposed rule amending the Uniform Code that the Department of State could consider, or any other comments on the proposed rule amending the Uniform Code, please contact Jeffrey Hinderliter by mail at New York State Department of State Division of Building Standards and Codes, 99 Washington Ave., Albany, NY 12231-0001; by telephone at (518)-474-4073; or by email at

Spoke with Gerard Hathaway on August 6th, 2019. Gerard confirmed Appendix Q was approved on Sept.27th, 2019.

Gerard Hathaway, R.A.
Assistant Director of Code Development
New York State Department of State Division of Building Standards and Codes
One Commerce Plaza, 99 Washington Avenue, Suite 1160, Albany, NY 12231
Phone: (518) 474-4073
Fax: (518) 486-4487

Uniform Code Rule Making June 2019 Page 7

Tiny Houses2020 RCNYS: Appendix Q (New)

Needs and Benefits: This code change provides regulatory guidance for the construction of Tiny Houses. The possibility of building one’s own home and the rising cost of homeownership, coupled with a desire for minimalist, simple living and to reduce the environmental impact of housing, have all fueled the Tiny House architectural and social movement.

However, the increase in popularity and in the number of amateur builders has led to safety concerns among design professionals and code enforcement officials. Further, while some have argued that a Tiny House could be built in compliance with the Residential code, in practice, to do so under 400 square feet and with a code-compliant loft has proven challenging, if not impossible. To address these significant obstacles, the 2018 International Residential Code (2018 IRC) added Appendix Q, which affords some lenience to dwelling units meeting the new definitions for “Tiny Houses” and to“Lofts,” without reducing the level of safety. New York State must adopt the provisions of Appendix Q of the 2018 IRC in order to provide regulatory compliance tools to designers and code enforcement officials in municipalities that choose to allow tiny houses in their zoning law.

The public will benefit from this code change through increased flexibility, lower housing costs, and the environmental benefits of a reduction in the manufacture, use, and delivery of construction materials.


There is a decrease in the cost of residential construction associated with this proposal. The average size of a new house in 2013 was 2,662 square feet.  With an average per square foot cost of $131.03 in New York State, this translates to $348,801 per home. Conversely, the typical cost of tiny houses in 2012 was about $20,000 to $ 50,000.

Uniform Code Rule Making June 2019 Page 7 


New: Tiny Houses

The 2020 Residential Code of New York State includes the adoption of Appendix Q titled “Tiny Houses,” which is applicable to single dwelling units and defines a “tiny house” as a “dwelling that is 400 square feet (37 m^2) or less in floor area excluding lofts.” Tiny Houses have both Land Use and Building Code requirements.

Permit Office – David Krug: (716) 851-4924 or can answer your questions regarding location on lot and other site issues. (Inspector Frank DiGennaro at (716) 851-5033 or and Tom Puglisi at (716) 851-4935 or can also assist you with your land use questions.)

The New York State Codes Division has issued Building Code guidelines for Tiny Houses: NYS Code Outreach – Tiny Houses

Peter Klemann can help in answering your Building Code questions. Email at is best or please call (716) 851-4911.

The City Of Buffalo

North Dakota: In The Process Of Adopting 2018 IRC: Have NOT Considered Appendix Q At This Time

On September 5th at 8:00 AM CST at The Great River Energy Building, 1611 East Century Ave., Bismarck, ND, a Voting Meeting of proposed building code amendments will be held for the participating jurisdictions and organizations.

The purpose of the meeting will be to vote on the proposed amendments from the public and Building Code Advisory Committee, 2018 International Building Code, 2018 International Residential Code, 2018 International Mechanical Code, 2018 International Fuel Gas Code, 2018 International Existing Building Code, and the prior amendments to those codes. These amendments will become part of the updated North Dakota State Building Code effective January 1st, 2020.

Spoke with Bruce Hagen with the North Dakota Department of Commerce on August 5th, 2019

I asked him if they are considering adopting Appendix Q for Tiny Homes. Bruce told me it had not been brought to the council yet. For information about the State Building Code or to submit a Code Amendment, please contact Bruce Hagen. It is too late in their code cycle process for the council to consider at the Sept 5th, 2019, but you can submit a recommendation using the code submittal form.
at (701) 390-4806.

Code Submittal  Form

Article Source North Dakota Building Codes

Ohio Adopted 2018 IRC: Did NOT Adopt Appendix Q

Personally spoke to the state of  Ohio- on July 25th, 2019 – They have adopted the 2018 IRC – But have NOT adopted Appendix Q at this time. I spoke with Jay Richards and he explained that Ohio does not typically adopt an Appendix, they prefer to wait until it is written into the body of the model code. Their focus is on safety, sanitation, and energy conservation. The state has no minimum square footage requirement for the size of a home. It is possible to request a variance and local jurisdictions might have different size requirements for homes. They do not regulate tiny homes on a chassis.

Residential Ohio Rules Effective July 1st, 2019

Article Source ICC Ohio

Yellow Springs

Tiny Home.  A structure built on a permanent chassis with or without wheels which must receive a certificate of occupancy from Greene County Building Regulations in order to be used as a dwelling unit or accessory dwelling unit on a single-family zoned lot.  Greene County Building Regulations will only issue a certificate of occupancy with proof of the following:
      (1)   Built as a manufactured home, proof of certification with a HUD seal is required.
      (2)   Built as an industrialized unit, proof of the industrialized home compliance certificate is required.
      (3)   Built-in another state, proof of their former certificate of occupancy is required.
      (4)   Built/constructed in another manner, proof of certification by a registered Ohio design professional.
(Ord. 2013-19. Passed 9-16-13; Ord. 2016-03.  Passed 4-18-16; Ord. 2017-23.  Passed 9-18-17; Ord. 2018-18.  Passed 5-21-18; Ord. 2018-41.  Passed 11-5-18.)

Article Source Yellow Springs Ordinances


Small House Specialty Code Effective October 1st, 2019

South Carolina

Greenville, South Carolina:  Tiny Houses 400 Square Foot or Less Residential Permitting Guidelines

The Code of reference for a site built small house is the 2015 International Residential Code (IRC) and as a case by case alternate method the 2018 IRC Appendix Q Tiny Houses as allowed by. (2015 IRC Alternate Method per section  104.11.)

Article Source Greenville County

South Dakota

Sioux Falls: Effective June 1st, 2019

  1. The International Residential Code, 2018 edition, including Appendix E, Appendix G, Appendix H, and Appendix Q as published by the International Code Council Inc. as amended, is hereby adopted as the residential building code by the city for regulating the design, construction, quality of materials, erection, installation, alteration, movement, repair, equipment, use and occupancy, location, removal, and demolition of detached one- and two-family dwellings and townhouses not more than three stories in height with a separate means of egress and their accessory structures, and provides for the issuance of permits and the collection of fees therefor.
  2. (b)  The adoption of the International Residential Code, 2018 edition, will become effective June 1, 2019.

Article Source Sioux Falls Planning 


Knoxville Adopted 2018 IRC And Appendix Q Effective January 1st, 2019 

Article Source Knoxville.Gov


Lake Dallas Tiny Village: Approved As A Planned Development Referencing 2018 IRC Appendix V-  Adapted By Approval Of Lake Dallas For Tiny Homes On Wheels

Lake Dallas Tiny Village

Lake Dallas Tiny Village Ordinances

Lake Dallas Ordinance 2019052 LD Ordinance Tiny Home PD Ordinance-107709 

Lake Dallas Ordinance 2017-14 Amending Zoning Ordinance Gotcher

Note: Appendix Q was previously called Appendix V

San Antonio: Adopted 2018 IRC and Appendix Q Effective June 21st, 2018

Confirmed by

Leslie A. Zavala

Sr. Plans Examiner

San Antonio ICC Code Updates

Development Services Department

Article Source San Antonio Express-News

Article Source San Antonio Gov

Smithville, Texas

Smithville, Texas is considering adopting Appendix Q. They are having a Tiny Home Forum on October 28th, 2019. Dan Fitzpatrick, our Director Of Government Relations will be speaking.

Smithville, Texas


Utah State Codes, developed by the Utah Uniform Building Code Commission Utah State Fire Prevention Board, are recommended to and approved by the State Legislature.

Uniform Building Code Commission Amendments 2021 General Sessions: Adopts Appendix Q Effective July 1st, 2021


Utah UpCodes

Springville Effective July 1st, 2019

Utah Gov

Article Source

Salt Lake City: Adopted Appendix Q Effective July 1st, 2019

Building Code Review & Adoption Amendments were signed into law by Governor Gary Herbert; this will go into effect July 1, 2019. Plans not previously accepted and fees paid for plan review to Salt Lake City Building Services will be required to be designed & reviewed under the new codes.

Appendix Q of the 2018 edition of the International Residential Code, issued by the International Code Council;

Article Source SLC Gov

Virginia: In progress including the 2021 edits thanks to the hard work of Thom Stanton and Dan Fitzpatrick!

All 2018 code cycle information is available on cdpVA


Sept 13th, 2019

Washington State

Latest News: Washington state adopts Appendix Q Effective date Feb. 2021 

Written Comments Regarding Appendix Q excepted until Sept 27th, 2019. Send to

Meeting Notes From July 31st, 2019 

Will Appendix Q Be Adopted In Wa?  State Meeting July 31st, 2019: Open To The Public

SUBSTITUTE SENATE BILL 5383: Effective July 28th, 2019

Section One: Appendix Q Can Provide A Basis For The Standards

The legislature recognizes that the International Code Council in 2018 has issued tiny house building code standards in Appendix Q of the International Residential Code, which can provide a basis for the standards requested within this act.

Section Six

The building code council shall: Adopt Building Code Standards Specific For Tiny Houses

(1)(a) By July 1, 2019, adopt a revised process for the review of proposed statewide amendments to the codes enumerated in RCW919.27.031;

(b) Adopt a process for the review of proposed or enacted local amendments to the codes enumerated in RCW 19.27.031 as amended and adopted by the state building code council.

(2) By December 31, 2019, adopt building code standards specific for tiny houses.

Article Source LegalWa.Gov

Final Bill Report ESSB 5383

The Council must adopt building code standards specific for tiny houses by December 31, 2019. Appendix Q of the International Residential Code is recognized by the Legislature as a potential basis for the adoption of new building code standards for tiny houses.

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This analysis was prepared by non-partisan legislative staff for the use of legislative members in their deliberations. This analysis is not a part of the legislation nor does it constitute a statement of legislative intent.


The only state not applicable to IRC building codes. Effective May 1st, 2018 WI adopted and enforce the 2015 editions of the IBC, IECC, IMC, IFGC, and IEBC.

Article Source ICC

Tiny Home Discussion: Marshfield, Wisconsin August 30th, 2019


Wyoming is using the 2018 IRC. This is one of the least restrictive states regarding building codes. Waiting for their response regarding Appendix Q.