Making Tiny Possible

Tiny Homes as Permissible Dwelling Units

The tiny home industry is growing and going places!

This article covers the basics of housing construction including an overview of existing classifications, where tiny homes on foundations fit in, and what’s required to bring forth a formality that makes it possible to build and live in a permanent or portable Tiny Home.

We’re rapidly making our way down the road to success. Here’s where we are, where we’re headed, why that matters, and what you can do today to make YOUR tiny dreams a reality!

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Planning, Permits & Inspections

First off, when we talk about “living tiny legally,” it means we’re searching for a legal and permissible path for use of tiny houses as our homes. From a building official’s standpoint, this means knowing a number of conditions and choosing the right fit. Let’s start with the basics.

• Land Use – In general, the path begins with the property as many things that define the “home” begin with the land it sits upon. How is the land zoned for residential use? Does the deed include any covenants and restrictions? What’s the minimum square footage for new construction in this zone? May special allowances and exceptions be made by variance, and what’s the process? What’s the lay of the land, and is it buildable? What utility services already exist, and what additional requirements may need to be met? Where’s the home site relative to boundaries, setbacks, easements, rights of way, and overlays including flood plains, plus climate, seismic, and high-velocity wind zones? What’s the soil content where the home is to be placed, and how does that affect planning and permitting? 
• Planning– What you plan to build is prepared and submitted in document form (plan sets) to your local planning office. This generally includes the property plan including the proposed location of the home. Such plans also illustrate your observation of any special conditions and restrictions, utility connections, roadways, and adherence to other property and zoning related requirements. Floor plans show the home’s flow, with elevation drawings illustrating the general look of the home including a cutaway drawing that shows the property grade, foundation type, and makeup, and structure of the home including proposed means of constructing the floor system, wall systems, and roof assemblies. 
• Engineering – Many times, plans require an engineer’s stamp that confirms that the proposed structure won’t slide down a mountain, sink into the sands, get blown off its foundation, or melt away as a moldering pile of rotting debris. Such engineering work is costly, though often necessary to secure plan approval and construction permits.
• Permitting – After the building official’s planning office reviews plans to ensure that — if built as planned — the home will meet community guidelines, building code requirements, and structural concerns, a permitting schedule is issued and outlines how construction activities are divided up into required stages for review and approval. 
• Inspections – The building office performs reviews of construction work at strategic times by a certified inspector to ensure all defects are corrected prior to “cover up.” Typically inspections are performed after site preparation; prior to and after any foundation pouring; after framing and/or envelope assembly; after rough-in of mechanical, electrical, plumbing, and related systems by licensed trade professionals; and through the finishing of the house for certification of occupancy that allows use of a house (structure) as a home (dwelling). 

It’s critical to recognize the role that land use, planning, permitting, and inspections play in new home construction. For “tiny homes on foundation” (THOF), permissible use must adhere to land-use restrictions and requirements. Movable Tiny Homes present a challenge as a building official’s perspective may be summarized as “what’s a home without the land it sits upon.”

Let’s look at different methods of home construction. 

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Site-Built Homes

Whether built as a custom-built home, a spec-built house, multi-family residence, or planned unit development, the term “site built” typically indicates that a structure is completely built from scratch, assembled from prefabricated materials, or allows modular constructs to comprise the finished unit.

Elements produced off-site arrive open for inspection or are “sealed” by a certified inspector who confirms adherence to quality assurance standards, construction codes, and other mandatory requirements prior to “cover up” at an off-site facility. In such cases, the 3rd party inspector is the building official working by proxy as an agent of record. 

Even if you’re building on “unrestricted” land, architectural planning, engineering reviews, municipal plan review and approval, periodic inspection, and certification are often key components for the legal use of any site-built structure.

Industrialized Building 

This is a superseding class of oversight that manages the administration of factory-based construction standards including those applicable to prefabricated assemblies, modular housing elements, turnkey manufactured homes, and pre-built accessory structures. 

• Prefab Components – Prefabricated elements are manufactured for installation in either a factory setting or on-site during home construction. The more commonly recognized prefab systems include Structural Insulated Panels (SIPs) and pre-built stick/steel framing including floor joists, wall panels, and roof trusses. 
• Home Kits – Designed to maximize budgets and time, kits are comprised of component parts that leverage factory-based prefabrication prior to shipping a collection of materials, appliances, and fixtures to the construction site for final assembly and installation. Prefab components and kits may be inspected in the factory or on-site depending on the degree of finish. 
• Factory Built – Encompasses off-site construction of finished housing modules. Like Manufactured Housing (see below), Factory Built Housing (FBH) may be produced off-site as single or multiple modules that are installed at the job site. Here too, a designated agent inspects both factory and finished product to ensure each module upholds specific nationally recognized standards, state-mandated building codes, and locally enforced requirements. A local building official typically inspects that site and foundation are properly prepared, modules are correctly installed, and site-built components meet locally enforced construction standards prior to issuing a certificate of occupancy. 
• Manufactured – Housing that adheres to the standard required by U.S. Housing and Urban Development (HUD) as produced in a factory setting. Manufactured Homes (MH) are off-site built dwelling units that conform to the HUD Code while meeting any state amendments and local requirements. Here too, an authorized third party often works as an agent of the state to review quality assurance of plans, production facilities, and pre-engineered housing units. Upon completion, such “mobile homes” are transported from factory to the build site where a local building official oversees all site preparation, installation on an approved form of foundation, proper anchoring of the manufactured housing unit to ground anchors, and connection of power, water, and wastewater utilities. 

Industrialized manufacturing, factory-based construction, and the use of prefabricated housing solutions are on the rise through a wide variety of stock options and custom constructs. Always check with your local building office for details prior to performing any site-based housing activities. 

Recreational Vehicles

RVs come in two predominant varieties using two different construction codes: 

• NFPA 1192 for Motorhomes, Travel Trailers, and Fifth Wheel campers that are less than 8’-6” wide in travel mode; 
• ANSI A119.5 for Recreational Park Trailers (AKA: Park Model RV) which are less than 400 sqft and greater than 8’-6” wide in travel mode.

From a housing standpoint, RVs are deemed only suitable for temporary, part-time, seasonal, recreational, and/or emergency use. While an RV can be designed to look like a house, RVs differ greatly in their construction requirements when viewed side-by-side with housing. 

Differences are more importantly reflected not in their visual appeal but in an RV’s general makeup which often includes lesser structural requirements, lower insulation factors, and other elements that are downgraded from residential requirements. True to their lineage as “campers,” such recreational accommodations include impermanent portability and use of a temporary connection to utilities in designated camping areas. 

The RV industry is largely self-governed and utilizes voluntary 3rd party inspection services and/or state oversight to prove conformance to prescriptive planning, construction, and quality assurance requirements. 

Such inspection services include those offered to manufacturer members of the Recreational Vehicle Industry Association (RVIA), a qualified third-party engineering and inspection firm like Pacific West Associates (PWA), and states that hold oversight of RV manufacturing with departments of transportation (DOT) providing licensure for vehicular use. 

Regardless of its true makeup and quality, it is important to note that a dwelling unit classified as a Recreational Vehicle may be forever deemed unsuitable to support full-time habitation. 

While the best built Movable Tiny Home may hold a certificate as an RV, so does a “code minimum” pop-up trailer and camping shelter. Where a “park model” RV may look more like a home, and may even follow many of the same general practices of construction, requirements for a code minimum PMRV pale when compared to similar minimums of compliance for residential construction.

A building official must uphold any form of recognized classification (i.e. certification) along with all restrictions on the use of such “recreational” units in upholding their intended purpose as temporary, part-time, seasonal, recreational, or emergency use… not as permanent housing.

Movable Tiny Homes

Everything listed above is already classified for use by their officially recognized definitions,  construction codes they uphold, the means of their inspection, and — ultimately — their certification for use by a bona fide Authority Having Jurisdiction (AHJ). 

Remember, a “tiny home on foundation” is simply viewed as a home that is built, assembled, or installed on-site following locally administered planning, inspection, approval processes. While housing modules may include a means of transport from factory to construction site, they are not themselves considered vehicles.

Unfortunately, Movable Tiny Homes (MTH) remain largely unclassified in that they lack formal recognition as an approved form of housing. Absent formal adoption, tiny houses are often deemed troublesome and contentious, especially where they lack: 

• Oversight – No credentialed building official or rostered agent reviews plans, ensures an upholding of standardized engineering requirements, inspects and approves construction activities, and issues appropriate certificates of use.
• Engineering – Prefab parts, modular dwelling units, manufactured homes, and even recreational vehicles must provide plans that illustrate methods, materials, and makeup of the finished unit. Engineering calculations prove that vehicular, structural, and environmental safety standards will be met in the finished work product.
• Quality Assurance – Provides that a high-volume factory, modular home facility, custom home builder, or DIY homeowner/builder has met specific minimum qualifications, holds required credentials to perform various aspects of home construction, and uses materials sufficient to uphold required standards.
• Inspections – Performed by a firm that is recognized by the state as qualified to perform plan reviews, engineered calculations, review of construction activities, and issue a recognized form of a certificate that indicates conformance to (and therefore compliance in) meeting or exceeding recognized standards and requirements.
  
• Records – Documentation is critical, and unfortunately absent in the bulk of DIY and low volume custom builds. Such records provide proof of compliance and requisite assurance that a finished unit upholds the core tenants of a construction code in safeguarding a building occupant’s health, safety, and welfare. 

Anyone deemed an Authority Having Jurisdiction, including state officials and third party agents, must uphold a level of quality that remains uniform and without prejudice. Such parties take on great liability when authorizing and certifying the use of a structure as a dwelling unit. 

It remains our collective role to bring forth a means to overcome the objections listed above. 

Let’s see what that takes!

Creating a Class for MTHs

Where the initial approach of Tiny Home advocates and proponents simply sought to unlock land use for an allowance of tiny houses “on wheels” and “on foundations,” the reality of need has unfortunately become quite more complex. 

So what’s it going to take to make it possible to legally use Movable Tiny Homes as a permissible form of housing:

• Standardization – Movable Tiny Homes will need to follow a specific set of construction protocols including their planning, inspection, and certification. 
• Planning – Movables are likely to follow a path similar to Modular Homes, and therefore will require proactive planning of construction activities for review and approval by a qualified 3rd party plan reviewer. 
• Engineering – MTHs are often said to be “built like a house,” so engineers will need to perform calculations that illustrate that models/units uphold a specific standard for a unit’s vehicular and structural use in a wide variety of environmental conditions and use case scenarios.
• Trailer/Chassis – Single floor MTHs can be built upon their chassis/carrier like modular homes, manufactured houses, and recreational park trailers. Such units are built on top of a basic chassis as “carriers” simply used as a means of transport. If desired, such units can be detached from their chassis without any negatively appreciable effect on the housing unit.
• Floor System – For lofted MTHs, it is typical in our industry to use the trailer as a replacement for the floor system. This makes the chassis a permanently affixed and integral component of the home’s finished composite structure. Therefore, the typical MTH chassis will need to prove its ability to perform as both a transport carrier and floor system (again, needs requiring prior planning, engineering calculations, plan approval, and inspection). 
• Framing – Movable Tiny Homes are inherently portable, and therefore subject to structural loads that don’t apply to a typical home. MTH frames will likely need engineered specs and inspection records to prove that the wall/roof assemblies are properly affixed to the chassis-based floor system. There are likely to be additional measures guided by industry standards to aid in full-time residential use which may require anchoring a MTH in the same fashion as a manufactured home.
• End Use – Movable tinies may be used in RV-like temporary, semi-permanent ADU, and more permanent settings. Each of these forms of parking/placement/siting all have existing protocols that will need to be met. Where stabilizing jacks are typically sufficient for RV-like temporary purposes, long-term use may employ practices used for placement of park model RVs and manufactured homes. Accommodations need to be made during planning and construction that meets RV-park, manufactured housing park, accessory dwelling, and primary dwelling residential requirements. 
• Inspection – Use of a recognized inspection agency will be necessary for MTHs. Floor plans, safety diagrams, systems plans, construction specifications, engineering calculations, plus photo, video, and text-based inspection records are a necessary part of product manufacturing that will become increasingly required for use of Movable Tiny Homes as a bona fide form of housing.

From the early days of the Tiny House Movement, common attractions to tiny homes is their flexibility of use, the relative simplicity of living, and lower costs for purchase and maintenance. Others have shared that the attraction is a lessening of hurdles to jump and costs to incur for new home construction. 

The unfortunate (and untelevised) reality is that Movable Tiny Homes will be forever stymied from providing their ultimate appeal — to legally use them as houses — without a way to check a box that says “Movable Tiny Home” on some official form at some point down the road.

And we’re on that road! We know where we are, let’s see where we’re headed. 

What’s Next…?

Through our collaborative Uniform Compliance Initiative (UCI), the Tiny Home Industry Association (THIA) plans to develop a specific set of standards for the design, construction, inspection, and use of Movable Tiny Homes as permissible dwelling units. 

Workgroups and sub-committees are now forming to review existing housing standards, to establish best practices, and to develop an “interim protocol” that can be used by tiny home “manufacturers” whether they are a DIY homeowner/builder, small volume custom builder, prefab component manufacturer, or turnkey housing construction facility.

It is a primary goal of the THIA to become accredited by the American National Standards Institute (ANSI) as an ANSI Standards Developer (ASD) and to develop standards for Tiny Homes in coordination with other ASDs such as the International Code Council (ICC), the RV Industry Association (RVIA), and the National Fire Protection Association (NFPA) while working in coordination with various government standards organizations such as the Department of Housing and Urban Development (HUD) and the National Highway Traffic Safety Administration (NHTSA).

Working in concert with the American Tiny House Association (ATHA), our collaborative effort is to increase state/municipal adoption of Tiny Home standards, exceptions (like IRC Appendix Q), and the development of amended variants of existing standards that provide an allowance for residential use of Tiny Homes.

Our collective hope remains that these cooperative efforts and actions open the door for future recognition of an industry-wide standard that promotes compliant Movable Tiny Homes as sufficient for use as fully permissible “portable dwelling units” that are suitable for permanent residential use when appropriately installed on an approved site.

Creating a new class of housing is a BIG deal even when we’re advocating for something called Tiny Homes. This remains a work in progress, so please excuse the dust.

What Can You Do Today…?

As indicated above, knowing your needs, the intended use of your home, location for placement of your home, and — most importantly — any mandatory construction requirements, processes, and documentation related to home construction will save you time and money in the long run. 

So start with the big question about Tiny Homes: How do you plan to use what you want? 

• Primary Residence – Building a primary residence on land in urban and suburban areas typically requires meeting construction codes, so site-built, prefab, modular, and manufactured homes offer the simplest option as they’re the most typical type of new construction and are most likely already supported by your local building department.
• Accessory Dwelling – Secondary units are increasingly popular and permissible. If you wish to build an Accessory Dwelling Unit (ADU) for your own use or as a rental unit, check with your local building office to ensure that your municipality already has a home for ADUs in your area. Beware of the temptation of converting a garage or garden shed into a residence without approval, as being cited for illegal activity is never fun and tearing apart your tiny house (AKA: Unapproved Structure requiring Destructive Inspection) could be heartbreaking. 
• Park Model – If you want a second home or have access to unrestricted land, a park model RV may be an appropriate route. They look like homes, often include lots of amenities like new homes, and can be relocated from location to location simply enough to satisfy occasional moves over short distances. In any case, an RV can’t usually be used as a permanent address, so you’ll have to make other accommodations there.
• Motorhome/Travel Trailer – If you wish to travel frequently, these recreational vehicles offer lightweight temporary dwelling units that may be used in RV parks and many manufactured housing parks. Lot fees are reasonable, and you can buy a preowned unit that’s ready to roll, or finance a new unit right from a local dealership. They may not look like houses on the outside, but they can quickly feel like a cozy little home on the road. 
• Movable Tiny Home – MTHs are a hybrid of these solutions, and therefore they are truly none of the above. While we’re working as an industry to develop a standard for Movable Tiny Homes, one does not currently exist. As such, access to financing and insurance is limited. If you’re going this MTH route, use of engineered plans, a reputable builder, licensed contractors, and an accredited 3rd party inspection agency may help “future proof” your tiny home as sufficient for use in RV parks, within park model tiny home communities, as an accessory dwelling unit, a primary residence on unrestricted land, and/or a convertible home should you chose to more permanently settle down. 

Being honest with yourself about your needs, budget, construction savvy, and — most importantly — the intended use of your home will help you quickly focus on what is the best approach to “tiny” housing. 

Plus, life is a highway. At least, where we start isn’t usually where we end our journey. While many want a Tiny Home to be their “forever home,” you’ll find that your life is much simpler if you remain practical at the outset of your journey. 

Do Your Part: Go Tiny!

It takes a village to raise a child, and a team to make a real home for tinies. 

If you love tiny homes and think we ought to have the right to “go tiny,” I encourage you to join the American Tiny House Association and participate in their locally oriented advocacy efforts. 

If you’re a professional or DIY homeowner/builder, an educator, a housing official, or another form of an interested party, I invite you to join the Tiny Home Industry Association and contribute your knowledge, opinions, expertise, and experience to our standards development process. 

Join us in Making Tiny Possible!