How Wide Can Your New Tiny House Be? (And A Brief Look At Height Restrictions Too)

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The tiny house movement is sweeping across the nation and more homeowners than ever are ditching their expensive houses for a more minimalist lifestyle. Unfortunately, making the transition to a tiny house doesn't mean everything is going to be easier right away. There are quite a few restrictions and regulations that you need to be aware of, such as how wide can a tiny house be, where it can be located, and how it can be transported on open roads.

Some of these regulations are set according to national laws. Many of them; however, vary from one state to another. Things become even more confusing when you take local city and county regulations into account as well. But you must do so before deciding to build or purchase your own tiny home. You don't want to find yourself fined or forced to move your new home because it doesn't align with some obscure building code.

The most significant regulations you need to familiarize yourself with deal with the overall size of the tiny home. These regulations are even more important if you plan to build your tiny home on wheels and want to be able to travel without purchasing expensive permits. Here are some important building codes and regulations you need to know.

How Wide Can A Tiny House Be?

First, let's consider a tiny home that you plan to build on a trailer and pull on the open road.

Any tiny house that is going to be pulled on the road needs to comply with the Federal Size Regulation for Commercial Motor Vehicles that are set forth by the Department of Transportation(DoT). These regulations can vary slightly from one state to another, but share some fairly common values across the country. In terms of width, it's safe to assume that the maximum width allowed for a tiny house is 8'5". Remember, this will include the wall width as well and not just the internal floor plan.

Hawaii is one state that deviates from this standard restriction. On their highways, the maximum width of any commercial motor vehicle is 9 feet. This applies to any tiny house connected to a vehicle via a trailer. If you're building your tiny house in Hawaii, then you can allow yourself a little more space during the design phase.

It's also important to note that these regulations apply to most roads but not necessarily all of them. Some roads will have signs that indicate the maximum width of the vehicles allowed to travel on them. As a driver, it's up to you to watch for these signs and to obey them at all times. Ignoring their guidelines could cost you a significant fine and may result in damage to your tiny house, vehicle, or public property.

The existing DoT regulations may seem restrictive, but they are designed with safety in mind. The restrictions were created with the average dimensions of most roadways in mind. They are intended to reduce the risk to other motorists, passengers, and public property. If you are in an accident or damage public property while ignoring these regulations, then you will likely be found at fault and be expected to pay for their expensive repairs.

What If The Tiny House Is Only Being Moved Once?

If the tiny house is only going to be moved once from its construction destination to its final destination, then you do not necessarily need to build it with these restrictions in mind. They do still exist, but they can be circumvented temporarily with permits and a proper escort. For example, you might have seen portions of a multi-family home being transported down the highway.

There are government protocols in place designed to help in these situations. They often involve completely shutting down certain roads and traveling with a police escort. Needless to say, it is going to be an expensive endeavor. You'll need to take these costs into consideration if you are budgeting your build and plan on exceeding the standard size limitations. The final size of the tiny house is going to determine what permits are necessary and what additional safety precautions need to be observed.

What If The Tiny House Won't Be Moved At All?

This is a great way to avoid expensive escorts, permits, and DoT restrictions. The disadvantage is that you lose the freedom that comes from having a mobile tiny house. If mobility isn't a primary concern, then you don't need to worry about the DoT size restrictions at all. But there are still local building codes and regulations that will impact how big or small any livable building can be.

A permanent tiny house placed on a foundation takes on the legal term of Accessory Dwelling Unit (ADU). There are some states that take a strong stance against permanent tiny ADUs and some zoning districts that do not allow them all. Most counties will have strict regulations regarding the minimum height and width but not necessarily a maximum height or width.

Unfortunately, there is no single blanket regulation that is standard across the country. You will absolutely need to check the local zoning regulations in the area where you plan to move the house before beginning construction. You do not want to make the mistake of building an ADU that is too large or small or even find out that the particular county of interest does not allow ADUs.

We can provide a few specific guidelines for states and counties where you might consider moving. Even with these guidelines, you should still check with local authorities prior to construction to ensure that regulations have not changed in recent months.

Alabama – Jefferson County: Allows ADUs up to 200 square feet in designated districts.

California: Does not allow a tiny house on wheels to be used as a permanent dwelling regardless of size.

Colorado – Park County: Allows ADUs with a living room of at least 220 square feet and at least 100 square feet per occupant if more than two occupants are living together.

Florida – St. Petersburg – Allows tiny houses with a footprint between 375 and 750 square feet.

Idaho: Most districts allow ADUs with a minimum of 150 square feet.

Louisiana: Has a state-wide International Residental Code for all cities. Allows tiny houses as long as at least one room in the house measures 120 square feet. Also requires that ceilings are at least 7 feet tall.

Michigan – Briley Township: Allows efficiency dwellings between 240 and 500 square feet. Length must be between 20 and 30 feet.

Ohio – Cleveland: Must have a square footage of at least 950 feet.

Virginia – Staunton County: Allows ADUs with a 200 square foot minimum.

These are only a handful of counties and states, but they demonstrate just how varied the regulations can be across the country. Many states like Hawaii are pushing for initiatives to make tiny houses more accessible to the public. They are believed to have a variety of benefits in specific areas.

Meanwhile, there are states like Alabama where they are fighting for legislation that prevents the construction of permanent tiny homes. Some of these people believe that tiny houses are unsafe or that they may negatively impact property values in the area.

Bonus Question: How Tall Can A Tiny House Be?

We've covered the issue of width if building a tiny house on wheels, but that is not the only factor that you need to consider. There is also the important issue of height. Unlike width, the height of commercial motor vehicles is not controlled by DoT regulations. Each state sets its regulations and they tend to vary between 13'6" and 14'. The major outliers are Colorado, Nebraska, and Alaska, which vary between 14'6" and 15' at maximum height.

Which of these height limitations is most relevant to you is going to depend on where you intend to pull your tiny house. If you want to be able to freely travel the majority of roads in the country, then you should keep the height below 13'6". However, this height will also include the height that is added by your trailer as well. It should be measured from the tip of the roof to the base of the wheels on the trailer.

Many experts recommended staying well beneath this height limit if possible especially if you are traveling through more populated areas like New York. Many bridges and overpasses have their own restrictions. For example, you can expect to encounter tunnels with height restrictions between 13' and 13'5". Your tiny house might be legal, but that isn't going to help it fit under that tunnel or through a tight archway. It's always a good idea to stick closer to 12'10" if possible.

Stay Up To Date

Remember, laws and regulations change fairly frequently. What is allowed today might not be allowed next year or after the next election. If you're designing and building your own tiny house, then you need to stay up to date with any regulation changes in the area where you plan to live. It's a little easier if you're going to buy the tiny house outright, but even then, don't let today's planning lead to a purchase error months or years in the future.

After you have decided upon the size of your tiny house, you will need to start thinking about other things like your water heater.