Design Choices: Foundations & Wheels

Like any home, there are thousands of designs to choose from using a whole massive range of different materials. And where there is not one found that fits your dreams, you can design your own!
We would recommend the simple flow chart process as depicted in the image above to start your journey.

1. Start to decide what housing works for your dreams. Do research in the process, like you are doing now!  Start thinking of budget here. We show this on the wheel above as step five, but it does need to be a factor at the beginning. Write out what you want your home to have, where you would like to live (think climate) and what message the style of it will reflect. From the outside and inside. It has to work for you and your life flow. 

2. The design and plan for your home must stem from a strong knowledge of municipal allowances & laws for a building.

3. Plan and verify through the entire process. Get all promises and commitments in writing.

4. Start getting quotes for various materials and services you have decided to use.

5. Reality check. See if your budget is realistic. You may have to adjust and start the process over with consideration of more or less money to spend.

Note: to build a safe, modern tiny building with all (or as close to regulatory compliances integrity; the average cost will be between $100 and $350 per square foot, assuming you are using all new materials.
There are so many builders and plans available (see our Canadian Connections page). Like any house hunting or design, choosing the right design and your team are the hardest part.
Mobile or Stationary Structure?

Often, one of the first questions will be, do you want to be mobile (or at least have the option to be) or are you OK to be on a fixed, permanent foundation?  That is where we will begin our first installment of Design Choices. Foundations & Wheels.

Know what you need to know!  As a result of building codes, any larger municipalities have antiquated laws that prohibit people from living in smaller homes (below a certain square footage) and to live with the freedom of proven sustainable solutions. If you are a wanting to be a mobile tiny home dweller, it is up to the municipality to determine what you can or can’t do. Or you and others must responsibly lobby for change.

Typically, for a mobile house, there is an insistence of being on land that is specifically developed for “RV” and “mobile homes”– like a trailer park. In this case, you would be limited in choices (often seasonal) and usually subjected to high land rental fees. Further, you may be dictated on how you handle waste black and grey water and if you are allowed to be off-grid in any way.

It’s messy, but there may be workarounds and solutions if you are properly inquiring to and working with the municipality to which you want to live. Thoroughly investigate before building your sustainable housing plan and money, get everything in writing. 

In Canada, many municipalities see the responsible and ethical gains with tiny homes; change is happening in select communities around the country as citizens fight to progress beyond unattainable and unsustainable housing situations.


Fixed Foundations

Slab foundation is simply a poured slab of concrete that a house is built upon and typically sits upon a footing that is constructed below the frost line– this is the easiest method.
At 3 to 6″ inches in thickness, with embedded steel rods (rebar) to prevent cracking and faulting. The house foundation is built directly on the soil with no basement or crawlspace. All water lines and waistlines are installed before the concrete being poured.  As with anything, you must know your provincial building code for all the requirements.
Crawlspace foundation consists of a perimeter concrete wall and concrete columns that will support the floor joists of your home. The distance between the soil and the first floor of your home is known as the crawlspace. This foundation is either built the ground level or over shallow excavation depth from 3 to 4′. The exterior foundation walls will support the building load, and several concrete Piers will be constructed in the crawlspace for extra support. Crawlspace foundations in the past have been built using the original soil as the floor; however, current building codes and standard practices are to have a concrete floor poured and in some cases insulation.

Basement foundation provides an additional, dry, safe storage and living space on the first floor of your home. Also, a place where utilities, such as water lines, electrical panel, heating and or off-grid systems are located. The basement foundation begins with a footing below the frost line and then concrete walls are erected approximately 8′ above.  A concrete slab is used for flooring.



There’s much to know, but don’t get overwhelmed. It’s not too complicated! Trailers are a great option if you want to take your home with you or move it around on your property for passive heating/cooling dependent on season. There are four common types of trailers on which one can build a home.

A tiny home on wheels is often equated to a recreation vehicle (RV). However, these homes are not built the same as an RV, most often offering far higher construction materials and quality suitable for all season living.

The Deck-Between trailer features the flatbed between the two wheel wells. The bed sits below where the summit of the wheel well reaches. For this reason, the bed can be no wider than how far apart the wheel wells are. The advantage with a deck-between trailer is that it sits nice and low to the ground, making it easy to build a taller tiny house, such as with loft(s).  Using drop axles with this trailer ensure the lowest possible floor level of the home. Very popular for THOWs.

Deck-Over has the flatbed above the wheel wells. Without the wheel wells getting in the way of interior space, this model gives you a little extra room on the sides for your home. These are a great option if you do not have a loft as they are too high off the ground for a second story/loft.

Dovetail trailers can be found/made as a deck-over or deck-between. The main difference between a dovetail trailer and those other two is that it features a section at the rear that angles towards the ground, like a ramp. You find this feature on trailers that are used to haul vehicles. These are typically not recommended for a tiny mobile home.

Gooseneck trailers can be found/made as a deck-over or deck-between. Its name comes from the special hitch that it has. To haul this type of trailer, you need to have a pickup truck with a ball hitch systems on the truck bed. The trailer front hitch reaches over the truck’s tailgate to attach. Very popular for THOWs.

Gross Weight Vehicle Rating (GWVR)
GWVR is how much weight the axles may carry. It is vital to know what the whole home weight is, or will be before acquiring a trailer. The axle rating should exceed the entire gross weight of the house, occupied and with all the planned contents. If you are not working from plans that detail the weight you will have at the end of the build, you will need to contact an engineer and accurately calculate. Add the weight of all the materials and contents.

For example, you may find a trailer that has two axles (dual axle), both of which can carry 2,721 KG (6,000 lbs). Your trailer, then, can hold 5,433 KG (12,000 lbs). You must factor in how much the trailer, house and the contents weight. Two axles good for  2,721 KG holding up a trailer that weighs 900 KG, can only support a tiny house and contents of 18,021 KG.  Now figure out occupancy, furniture, appliances and other belongings for the total.

Tri-axle trailers are also another option.  The third axle does take away a bit more interior space, however, depending on the house weight and length, tri-axle may be the best.

Breakaway Trailer Kit & Lights
Make sure you have them! Any new manufacturing of a certified trailer is to have these for transport compliance.

Trailer Jacks/Supports
While these can be purchased separately, we recommend you have the manufacturer of your trailer also supply jacks for levelling the trailer/house when stationary.  Some manufacturers can weld adjustable jacks onto the bottom of a trailer to facilitate easy levelling.

Make sure the v-class hitch is proper for the weight you will be pulling! Hitches also have their capacity for weight, called the tongue weight; the amount of weight that can safely be suspended from the receiver (or the maximum downward force exerted).

Security: Hitch Locks/Wheel Locks, etc.
People have had their entire tiny homes stolen by thieves. Take precautions and get the absolute best trailer hitch lock that is on the market. Spare no expense! In addition to a hitch lock, consider wheel locks and a hidden GPS locating device built into the house, powered by a recharging and long-lasting battery. Should a criminal find a way to pick up your house, trailer and all and place it on another transport unit, the authorities will be able to track it down!

Legally, your home can only be 259.08 cm (102″) wide, as per Canadian transport laws.  Wider structures require a special license and transport preparations that may want to be avoided due to additional costs.

The maximum height in Canada and through most of the USA is 411 CM (13′ 6″). As for maximum length is depended on the province. CAA has a handy reference here

Always verify size, weight restrictions and the required licenses with the Provincial Ministry of Transport relevant to whom you are a citizen.  It will not be a sustainable home if you are not allowed to transport it or run the risk of fines and impound!

Custom Trailer or Salvaged?
Many tiny house builders that choose to be on wheels have their trailers recovered from transport industries and old RVs. While this may be acceptable, it is wise to consult a qualified, experienced professional before investing.  We have heard some horror stories where self-builders and tiny house companies have used salvaged trailers without knowing the science. The results may be terribly unsafe and massive losses! Take no chances!

Do keep in mind that not all trailers are the same.  A transport trailer is not necessarily built around the perimeter having much strength.  It is designed to deal with the load in the center and floor.  RV trailers may also have this issue as the materials they use are not going to be the same as your home construction, such as wood frame 2×4 walls with insulation and fire suppressing wall panels.  RVs are made to be light and often only for three seasons.  Not the same as what you may be building.

The vast majority of your house will be distributing the weight on the perimeter.  You need to be sure this is accounted for. THAC recommends having a trailer custom made and gaining all of the confidence with it; assurance the home will be reliable, the transport and engineering certifications are legitimate and current.

If you have purchased your “tiny house on wheels” plans, the trailer requirements should be included in an engineer’s drawing.

Cost (for new)
It depends on the home design requirements size and features, but we have found in Canada that the costs can be anywhere from $4000 to $15,000. In our experience, getting quotes from four places in Canada for the same specifications (from an engineer’s drawing) of a deck-between trailer showed that the difference could be $6,000 from the lowest quote to the next!  Get many quotes from many proper fabricators.  We have some trailer builders on our Canadian Connections page that may be able to assist.

While the cost can easily be 1/4 to 1/3 the entire build cost, at least it is for us; don’t cheap out on the trailer. It is the foundation and critical for safety, security of you and anyone else on the road; everything is riding on it!

Consulting a reputable trailer fabricator will help you understand many other aspects of the trailer you need for your tiny house and flush out any of the sections covered here.


Other Trailer Essentials to Research and Acquire

  1. A license allowing you to tow.  In most cases, there is no additional license required, however, do refer to your province of residence for the requirements.
  2. If you have never hauled large loads, you may need practice before making your journey with all your worldly possessions.
  3. License plate requirements.
  4. Electric breaks with a breakaway system.
  5. Breaking and back up light kit.
  6. Several scissor jacks telescopic jacks or blocking to allow for the trailer and house to properly be levelled on the ground. For ours, we will have eight scissor jacks welded to the bottom of the trailer ready to extend and level the home.

Towing Vehicle
The choice of vehicle depends on the trailer system & hitch, but mostly the weight of the entire house and contents.
A 3/4 to 1-ton truck will suffice for many tiny houses that weigh less than 16,000 lbs.

Some of the things you need to look into are:

  1. Is there a minimum square footage amount that designates a structure as a permanent home?
  2. Can you legally park it on the property in question?
  3. Can you park it on the property without a permanent dwelling being present there too?
  4. If so, can you live in your home as a primary residence (four seasons)?
  5. Do the local zoning laws permit accessory dwellings like your tiny house on a trailer? If so, are there minimum requirements for square footage?
  6. Does the accessory dwelling need to be built on a permanent foundation?
  7. If you are not entirely tied into existing sewage systems, you will need to know what the wastewater (black and grey) laws are. Most municipalities require this hookup for sanitation and public health reasons.
  8. Investigate how to have your home insured.

Because of the nature of tiny houses, especially those on wheels, you may have some issue getting insurance. SOME insurance and finance companies have not caught up to the tiny house movement, yet.  Shop around.  It is not impossible to get insurance under some provisions outlined by insurance companies. 


Photo: Tiny House Trailers