Tiny House Building Codes

Build your tiny house know-how on a solid foundation of building types, code compliance, and help lead a shift for legal habitation in smaller structures.

Tiny Houses Fall Between Cracks in the Code

Build your tiny house know-how on a solid foundation of building types, code compliance, and help lead a shift for legal habitation in smaller structures.

Tiny houses fall in the cracks between existing, and accepted, types of homes. To help you go boldly into the fight, we've provided a little overview to help you be an aware buyer, and keep you compliant with codes should you go the DIY route. Oh... and a closing bit of RAH-RAH LET'S GO TEAM!

Overview of Applicable Standards

To date, there are no official tiny house building codes, but that doesn't mean you're in the clear to build whatever you want.

Some manufacturers construct units to meet the appropriate building standards such as those of the International Building Code (IRC), U.S. Department of Housing and Urban Development (HUD), Park Model RV code (ANSI), and any Uniform Statewide Building Code (USBC).

Let's take a closer look at what might might apply when building a tiny house on wheels, known as a THOW. Now you may ask, "why the initials?" Our guess, because we're more official with our own acronym [>:-).

International Residential Build Code (IRC and IBC)

The International Code Council (ICC) is the conglomeration of three governing bodies who came together to cooperatively develop the International Residential Code (IRC) which has a rich and intriguing history based on safety protocols for addressing high wind conditions and strong seismic concerns.

If you are building a structure for placement on a permanent foundation, be sure to check with your local municipality for specifics on the planning, permitting, inspection, and certification process. While the tiny house universe is full of rebels, building a conventional home will likely fall under the purview of this category.

As with many things in life, when it comes to using codes and standards to build a permissible structure "you may not like 'em, but you're gonna have to use 'em!"

Industrialized Building Units (IBU)

These may be built as single standalone units or modular components that are built in the controlled environment of a manufacturing plant before being transported to the build site. Plans, building methods, delivery vehicles, and final placement are strictly governed. Indiana's application process is nicely outlined.

Mobile offices, classroom trailers, and other commercial buildings are examples or Registered Industrialized Buildings, and are often built on a basic trailer for quick relocation with safe and secure leveling. Garden sheds and other forms of "portable buildings" -- often employing skids for off-site construction, relocation, and stabilization -- are a form of Unregistered Industrialized Building, and are not meant for habitation.

Should you wish to use either an existing Registered or Unregistered Industrialized Building as the base for your tiny house, be sure to check with your local building department first on the viability for a Change of Occupancy permit. Do this before you procure, relocate, and -- most importantly -- start adapting the structure from its intended and permitted use for another purpose.

Remember, once you begin building on site -- whether on skids, wheels, or permanent foundation -- you are subject to inspection. There are even methods built into the Virginia IBSR code for citing those who are non-compliant and move the building off-site. Note hwo there's direction to cite the name of those who help relocate your project and it's destination.

Big Brother is watching, so it's better to know before you go and start building. Check your state's codes first!

Manufactured homes (MH)

Previously called "mobile homes" or "trailer homes," Manufactured Homes are a form of Industrialized Building. As MHs are intended for habitation, they must "meet or exceed" the Housing and Urban Development (HUD) national performance codes. The nationally applied HUD standard supersedes state. county, and municipal codes.

More recently, "modular homes" have been introduced that include a wide variety of component elements that comprise various features of the finished home. The components may be mixed-n-matched to provide myriad configurations and floor plan layouts. All modular building units must be pre-approved for code compliance and inspected at the manufacturing center by a state approved agency before transportation to the building site.

Modular building units are transported in one or more sections to the property, and "sited" on permanent foundations. Permits and inspections are necessary for the foundation system, anchoring method, and any on-site construction, after which the homeowner is granted a Certificate of Occupancy (CO).

Upon receipt of the CO, most of us will pop some bubbly!

Park Model Recreational Vehicles (PMRV)

Spoiler Alert: Sadly, while this standard may seem the simplest code to apply to your little home building project, it isn't accepted by local building departments for construction for a tiny house on wheels.

First the good news. A park model RV is built on a permanent chassis, with removable wheels, axles, and tongue for placement set on semi-permanent foundation. PMRVs do not typically require a Certificate of Occupancy (CO). Once in place skirting, decking, and other features that expand the look of an otherwise utilitarian road-ready structure, albeit within the guidelines provided within a campground's code for compliance.

As a base structure, park model RVs provide a larger footprint than the standard RV's maximum width of 8'-6", with PMRV designs being up to 399 square feet (HUD applies to 400 sf or larger). This maximum square footage excludes lofts as they do not meet minimum standing height requirements and may be presented as "elevated storage" or furniture like bunk beds.

Now the tough part. PMRVs are designed for recreational use and seasonal living, and their standards often fall well below HUD's "code minimum" standards for full-time habitation.

And that's the "kick-out clause" that keeps tiny house builders a wee bit over the border.

Park Model Certification

From a compliance standpoint, park model RVs that carry an official seal are built under specific certification criteria outlined in an American National Standard Institute's document: ANSI 119.5.

ANSI 119.5 Park Trailer Standard outlines over 500 design, construction, and safety protocols for certifying compliance for manufacturers of park model trailers. The PMRV standard of certification is administered and enforced by the Recreational Vehicle Industry Association (RVIA) in conjunction with other third-party certification organizations like Pacific West Associates (PWA).

Manufacturers listed with RVIA as certified member manufacturers agree to uphold the standards outlined within the ANSI standard and accept a random site inspection every few weeks. An official seal can be affixed only by member manufacturers of these professional associations, and while many tiny houses "meet or exceed" most of the prescriptive code, the manufacturer is certified, not the structure.

Some areas are seeing success in the application of ANSI 119.5 as a building standard for tiny houses on wheels and accessory dwelling units (ADU). However, the RVIA carefully guards the use of ANSI 119.5 for their own purposes within the recreational vehicle -- not housing -- industry.

Curious to study the code? Download a copy of ANSI 119.5 here.

Tiny House on Wheels (THOW)

The iconic tiny house is a small, trailer-based, road-ready structure with all the amenities of home. This micro-sized domicile, often includes a living area, sleeping space, food preparation features, a lavatory, and in many cases, a shower, lots of shelves, clever built-in storage solutions, and multipurpose spaces with multifunctional furniture.

The mini-home often encompasses a wide variety of architectural styles, and builders exercise greater flexibility in the choice of color palette, styles, and aesthetics than employed by conventional homes. Tiny house people encourage community building, with many mini-homes being constructed by paid-participation workshops, free meetup groups, and groups of families-n-friends who comprise an ad hoc team of backyard builders.

There is an increasing wealth of tiny house resources available including full-fledged building plan sets, how-to videos, and documents, with many freely available online. Some consider the Tiny House Movement to be a building revolution, yet there are many challenges and obstacles that face tiny house builders.

Stuck in the Middle

A tiny house, sometimes referred to as a tiny home, lacks any form of real definition. This open-ended flexibility has given rise to truly ground-breaking change in the ways and means of small space design and home construction. While the lack of official standards may be viewed as a wink-and-smile symbol of freedom, the lack of our industry's official designation may be our greatest Achilles heel.

The desire to build one's own home is a core human trait. And, the Tiny House Movement is filled with do-it-yourself homeowner designer/builders relying on various tools for inspiration, engagement, and self education. Some press play and learn from professionally produced how-to videos. Others chose to create custom plans, purchase ready-to-assemble kits, or commission prefabricated shells. More still want a fully finished tiny homes on wheels that ready to roll. And for those seeking a true hands-on experience participate in tiny house workshops that provide labor and guidance throughout the process.

Regardless of what you'd like to believe your All-American rights and freedoms to include, the government provides strict direction to guide and regulate home building. Like it or not, the codes were initially designed and are continually updated for the interests of public safety, and we've put people in place to govern and enforce accepted zoning ordinances and building standards.

While everyone wants to craft their own home brew into a best-of-blend for prescriptive standards and best practices... while we'd like to say our homes meet-or-exceed most of the standards... while we'd like to think we can build what we want, where we want, and how we want... well, that's not a reality here in the modern day U-S-of-A.

Looking to the Future

From my personal perspective, I believe it's best to assess what is accepted practice, and learn from what is now along the cutting edge. We have the opportunity -- right now -- to be heard by our representatives, and offer a helping hand in the modification of policy for legal tiny house building and living.

Unfortunately, the cuteness of tiny houses has us caught up in the moment, and many "tiny house" builders enjoy a seemingly loopholed exclusion from existing building standards. From a long term perspective, I believe the sky darkens and a day of reckoning is a-comin'. Be forewarned, states and municipalities are increasingly wised to proposed ways to crack the code, stay under-the-radar, and live off-grid. It's the job of a building code enforcement team to find, fine, and restrict those who attempt to beat standards within our existing systems.

Wishing and complaining won't help. We owe it to ourselves to help our local and state representatives understand our wants, needs, and desires. Let us catalog who we are, agree upon needs for safety, outline our likes in new features for small structures, and affect change through legal means within the system. Let us look at existing standards and define what makes a tiny house different from larger model homes currently accepted as a "good enough" minimum in size and standard. Let us applaud this revolutionary shift in thinking, and show how bigger isn't necessarily better when carried on the shoulders of a collapsing middle class society in a shrinking global economy.

There's a growing gap between the minimum sizes and standards required by many municipalities, and the adapted interests in more minimal living as represented by the tiny house community. Its true, we have our easily identified icons and online advocates, though we lack a larger voice that speaks on behalf of the greater good.

Let us do more than just sit, smile, and enjoy the show. We have genuine needs and interests, and must demand more than the false hope promoted by those who continually cash in on the tiny house trend.

Shared Goals and Aspirations

My goal is to understand the existing requirements and find ways to design small homes that legally live within the prescriptive guidelines. Further, I hope to help foster change where outdated codes and overly restrictive zoning regulations limit our right to live in smaller homes in communities or private land.

Public safety concerns always add a layer of complexity and will maintain a form of restriction. However, if our proposed practices do not pose harm to ourselves or others, what's the big issue about a tiny house?

In the end, we have our rights, and must fight for our freedom. Join us in this time of change, or merely wish us luck with this ongoing challenge!

Live Large -- Go Tiny!

Thom Stanton's picture

Here's a link to a page on Tiny House Talk on How Do I Get Zoning Passed for a Tiny House. Enjoy! 

Thom Stanton
Founder/CEO, Timber Trails LLC
Lead Organizer, RVA Tiny House Team (Meetup Group)
State Chapter Leader, American Tiny House Association