CHAPTER
12

Designing Your Tiny House

In This Chapter

• Deciding whether to design from scratch or to buy plans
• Learning the steps to design your own tiny house
• Designing with software programs
• Understanding the importance of getting plans engineered

Beautiful architecture has the power to inspire and invoke feelings of calm, contentment, inspiration, and joy. On the other hand, if a space isn’t visually appealing and lacks practicality and functionality, it can make its occupants pretty miserable.

Many architects and designers have devoted their educational training and careers to this art form. Fortunately, by applying some of the tools of the trade, time, and energy, you can create your own beautiful set of tiny house plans, too. In this chapter, we show you how to choose a good set of existing tiny house plans, how to design your own tiny house, what software programs bring it all together, and how engineering is the best line of defense when it comes to safety. Let’s get drawing!

Altering Existing Plans

Tiny houses are so personalized that it’s unusual to find one that meets all your needs and wants. What’s more common is to find one that’s close, but requires some alteration to make it just right. An online search for tiny house construction plans should yield numerous options to get you started.

If you found a set that’s close to what you want, you’re off to a great start! Much of the preliminary design work has already been done for you. Although exciting, this can pose its own set of challenges, so be sure to choose wisely. Let’s go over the factors you need to take into consideration when it comes to existing plans.

Choosing a Plan

High-quality and complete sets of tiny house plans do exist on the market and more are being added regularly. If you’re considering a set, make sure they contain all pertinent construction details, such as a clear floor plan, exterior elevations, construction sections, plumbing and electrical details, and engineering details.

Don’t settle for an incomplete set, especially if you’re a beginner builder. You’ll likely end up wasting time and money if there are omissions. Look for ones that have been built by at least a couple happy customers and spare yourself the job of becoming the guinea pig.

Lastly, consider the level of customer service offered by the company selling the plans. It’s always a good idea to send an introductory email with a few questions before you buy plans to see if the designer responds promptly. Because questions will certainly arise during the build, you’ll appreciate the peace of mind knowing there’s someone who can help you.

Every Change Counts

The biggest risk in altering existing plans is that a simple change can create an unforeseen and negative consequence. For instance, let’s say you don’t like the current placement of the kitchen in your purchased plans. You change it from a U-shape configuration to a modified galley and place all the cabinetry and appliances on one wall. The other wall you leave relatively open and place only lightweight items along it.

What you don’t realize is that the original kitchen layout was a key component in the weight distribution calculations made by the engineer. By moving the kitchen around, you’ve thrown the design out of balance. Before making any modifications to an existing set of plans, make sure you understand how those changes will affect your tiny house.

TINY WARNING

There’s nothing wrong with taking an existing set of tiny house plans and modifying them. That said, you must have a clear understanding of how a tiny house design comes together so that you can predict the effects each change will have on the overall structure.

Changes in a tiny house layout can affect other aspects in a design as well. By moving a room, wall, sink, or other detail, you might start a chain reaction of challenges to overcome. Sometimes, if your changes are relatively significant, this effort can become so large that it might make more sense to just start from scratch.

Start with Grand Ideas

Even though you’re designing a tiny house, we encourage you to start out by dreaming big. Sit down with all members of your household (if there are others) and make a wish list of everyone’s tiny house hopes and dreams. This is a fun opportunity to uncover what you value in a home.

The intention of this exercise is to get everything on the drawing board. No wish should be left behind. You don’t want to regret omitting something later on because you didn’t think it would fit. You might be surprised at just how much you can get in a tiny house when you use creative design.

Our hOMe wish list was gluttonous:

• Two bedrooms
• Home office for two
• Full-size kitchen
• Seating area
• Large bathroom
• Lots of storage
• TV lounge
• Comfortable stairs to the loft

To be honest, we worried we were being a bit excessive as we listed everything. After several redesigns, however, we managed to fit everything in our 28' tiny house.

Prioritize each item on your list from “very important” to “might be able to let this one go.” If a downstairs bedroom is at the top of your wish list, make sure to put this in the number one spot. If there’s more than one of you doing this exercise, create your lists either together or separately. If you do them separately, you can compile them into a single list later.

What You Really Need

After a week or two, review your wish list(s). Having some time off gives new perspective on what you included on your list. Are there items you can cross off the list right away or perhaps move on the priority list ranking? You might be surprised at how many wishes you’re willing to part with without protest. Do this exercise several times, giving yourself a few days in between until you’re left with a list that represents what you truly want.

TINY WARNING

What we think we need can be quite different from what we actually need. We’re bombarded daily with advertisements and programmed to think we want things that actually add no significant benefit to our lives.

As you learn to tell the difference between what you want and what you actually need, you’ll start seeing opportunities to simplify your life, as well as the belongings you carry with you. You’ll also get clarity on what needs to be on your dream list. Remember that going tiny is a process partly dependent on reprogramming old habits. This can take time, so be patient, The more time you can give to this process, the better your tiny house will turn out in the end.

Double Duty

Let’s say you want a couch in your tiny house and everyone in your family agrees. The problem is that sofas are huge and you shouldn’t compromise your living space with something so large unless it serves at least two functions— maybe even three. Instead, look for a sleeper unit with embedded storage. Now your space-hogging sofa serves three purposes:

• Seating area
• Guest bed
• Storage unit

This combination of purposes might be enough to justify the loss of floor space.

The stairs in hOMe are a perfect example of multi-functionality; they not only provide comfortable access to our sleeping loft, but also 25 sq. ft. of extra storage space. This is enough for our winter jackets, hats, gloves, shoes, keys, and more. We even plumbed it to fit a washer/dryer combination unit.

The hOMe stairs provide comfortable access to our sleeping loft as well as an extra 25-square-feet of storage.

Introduction to Design

Designing a tiny house from scratch might seem intimidating, but if you know where to begin and what steps to take, it’s fun and rewarding. Keep in mind that most tiny house dwellers designed their own home with no previous experience. If they can do it, so can you!

Sometimes the best approach to designing a tiny house is to start with a totally blank canvas rather than trying to fit bits and pieces of other designs into a floor plan. There’s something to be said about approaching a challenge with a clear mind.

Visualizing the Layout

It’s time to get creative, so grab your edited wish list! Don’t bother drawing anything that looks like a house just yet. Instead, start by drawing simple circles and labeling each one to represent all the items on your wish list.

This process will transform your list into a picture of sorts called an item-priority circle drawing. Draw the size of each circle relative to the level of importance you’ve rated the item. For example, if you really want a full-size kitchen, use a large circle for that item. If, on the other hand, the bathtub is low on the list, draw a small one around it.

Bubble diagrams are an easy yet effective way of visualizing how a space flows together.

Next, turn your circles into a room-relationship bubble sketch, which is a series of simple hand-drawn circles that represent the rooms you want in your house. As before, the scale is important and the size of each bubble should be relative to the size of the room it represents. The placement of the bubbles is also important. For example, don’t draw the bathroom directly next to the kitchen unless that’s where you want to place it. Bubble sketches are an easy way to assess the relationship between various spaces in your tiny house and to see how everything flows together.

With both the item-priority circle drawing and room-relationship bubble sketch complete, you should have a sense of which room goes where, what each one contains, and what the movement patterns between spaces look like. At this point, you can start laying out your plan in detail and working with graph paper or a computer program.

Designing Your Floor Plan by Hand

A floor plan is an architectural representation of a structure or room from a bird’s eye view. Even though it’s just a two-dimensional depiction of a space, it gives detailed perspective and is a great starting place when embarking on the design process.

Floor plans should be drawn to scale, meaning that the proportions between all objects and lines should be true to form whether the house drawing is tiny or large. The most commonly used scale in American architecture is ¼" equals 1'. This means that a ¼" object or line represents 1' in actual space. If something is drawn to full scale, it’s life-size and a bit difficult to carry around in your pocket.

The best way to ensure your drawing is accurate is by using an architectural/engineering scale. This triangular ruler is like a standard ruler. However, it contains several different scale options on it. You can draw with incredible precision by using an architectural/engineering scale. Always make a note on your sketch what scale you used for reference. A high quality mechanical pencil as well as a nonsmudging eraser are the only other materials you’ll need.

Here are the steps for creating a hand drawn floor plan:

1. Exterior walls. Lightly draw the exterior walls of your tiny house. Use your architectural scale for precise lines. Make sure to incorporate the thickness of the exterior wall in your drawing. For the highest level of accuracy, the depiction of the exterior thickness also should include the framing material, siding, and interior finish wall materials. Although it’s not common practice in residential architecture, it’s important to include these items in a tiny house because of the extreme floor space and total width restrictions.

2. Interior walls. Again, be sure to draw interior partition walls using light lines. Be sure to account for wall thickness. It’s easy to forget that information, but a miscalculation of even 2" can cause issues in a tiny house design. An improperly measured partition wall in one of our hOMe sketches nearly threw off our entire cabinetry layout.

3. Doors. Lay out your door(s). Erase any lines on the same plane your door openings will go. Draw a quarter circle to represent the direction the door opens. Refer to the floor plan image for instruction on how to draw a pocket door. A typical entry door is 36" wide.

This is a hand-drawn sketch of our 28' hOMe plans. There are certain industry conventions applied to floor plan sketches. Once you learn what they all represent, you’ll be able to understand any floor plan drawing.

4. Windows. Windows can be depicted as boxes superimposed over the wall plane. For more information on window and door placement strategies, see “Windows and Doors,” later in this chapter.

5. Appliances, cabinets, and fixtures. A typical lower kitchen cabinet depth and countertop is 2'. Uppers are generally 1' deep. Lower cabinets are depicted with a solid line while uppers are shown with a dashed line. Refrigerators and ranges/ovens are drawn just a tad deeper than cabinetry. Refer to the floor plan image for how to illustrate fixtures and appliances.

6. Finishing up the first floor. Clean up any smudges and label appliances and rooms if you desire. If you’re pleased with this floor plan and feel fairly confident your exterior wall dimensions won’t change, take a pen and go over the exterior lines. Make them pretty bold. We don’t recommend you do this with your interior walls, cabinetry, and appliances, just in case you want to make modifications.

7. Lofts: If you plan on incorporating one or two lofts into your tiny house, take a separate piece of paper and place it atop the first floor elevation. With the exterior walls clearly marked in pen, you should be able to see them through the top piece. Copy the exterior wall outline (except for the windows) onto the second sheet and draw out your lofts in pencil. Incorporate any second-story windows into that sketch.

8. Mechanical/electrical systems. Before you can really go into depth with this step, you’ll need to research the following systems: water heaters, electrical panels, HVAC sources, water filtration systems (if needed), and mechanical ventilation systems. If any of them require a significant amount of space, be sure to account for where they’ll be placed. Make sure to include a utility closet in your design for housing at least some of these items.

In terms of ceiling lights and switches, you might want to wait until you feel pretty set on your floor plan. Add those details once all the larger pieces have found homes. Don’t race past this step, however. Lighting is incredibly important in any space, especially a tiny house. Be sure to give this adequate attention in the design phase.

As you go along, try to see your design through fresh eyes when possible. In one of our hOMe plan renditions, we realized we had forgotten to add a refrigerator! We were so focused on other details we completely skipped over it.

Windows and Doors

You’ve likely established your door placement, but perhaps you haven’t determined where your windows will go. Windows are important not only for allowing light into your house, but also for augmenting your design.

There’s an art to knowing how to make the most out of window placement. The Rule of Thirds is a great place to start. It’s a composition concept used in photography, but the principle can be applied in architectural design as well. By dividing your tiny house design into thirds both horizontally and vertically, you create a grid of nine rectangles. Important elements (such as windows) should ideally align on any of the four corners of the grid lines. This adds visual interest to a design.

We incorporated the Rule of Thirds in our hOMe design by placing windows and the door toward the four corners as much as possible.

Another important consideration for your windows is line of sight. Optimize the placement of windows by anticipating your views from the inside out. If you plan on being parked in one location, be sure to incorporate views you want and minimize those you don’t. If you intend on being mobile, design your sightlines for the best use of light and views in a general sense. You can always add multi-directional blinds later if your new view isn’t as appealing as you had hoped.

Solar gain on south facing windows can warm a space for free during cold winter months. It can also overheat that space in no time on a hot and sunny summer day if you don’t plan for ways to protect the windows from that sun. A THOWs has the unique advantage of being able to move with seasonal cycles, allowing you to take advantage of natural heating and cooling. Simply pull out into a clear open spot in the winter, orient your longest wall with most windows towards the south, and in the summer, tuck it away under the shade of a tree.

Design Programs

A lot of design details are challenging to visualize without having a 3D perspective. While some people are talented enough to build physical models or draw a house in 3D, the rest of us need other tools and solutions.

Luckily, we live in a world of computers, applications, and multi-media options made to simplify the design process. That said, some of them have steep learning curves even for those with a computer background.

There are several architectural design software programs available that can give you 3D functionality. There are new programs on the market all the time, so be sure to consider all of your options before you get started. For example, we recently discovered an app that allows us to map out 3D spaces with our smartphone camera. By literally tracing our hOMe layout with the phone, this program translates that data into a floor plan. These technologies are getting more sophisticated every year.

Let’s look at some of your options in the following section.

SketchUp

In designing hOMe, we used SketchUp (sketchup.com). We had never used the software before, so our learning process was slow. We invested a couple weeks working through free, online tutorials until we felt proficient enough to design our own tiny house. In the end, we were pleased with SketchUp’s functionality and ability to create a working 3D representation of hOMe.

The biggest advantage of SketchUp is that the drawings are created in 3D from the beginning. Within this environment, you can move figures, furniture, and other details around easily. This makes checking the functionality of a space quite simple. SketchUp provides you with a human figure drawn to scale. As you move the figure through the house, you can double check that you’ve budgeted enough space for all components.

Pros:

• You can use the free version for most needs.
• Very powerful design options.
• 3D design for easy visualization of the space.
• Lots of online tutorials available.

Cons:

• Can be a steep learning curve.
• 3D only may make drawing the design difficult.
• Lines drawn in the wrong plane cause major problems with overall design.
• Pro version required for best results, which is fairly expensive.

TINY TIP

You’ll need to ensure that your lines are drawn in the correct plane or axis when working with SketchUp. Because you draw in three dimensions, a line placed even one degree out of plane can cause all kinds of headaches. Make sure your lines are precise and snapped to the correct axis to ensure the software works correctly.

You can do a lot with the free version of SketchUp. However, to create your tiny house design to its fullest, we recommend you upgrade to the pro version. There are a lot more add-ons and functions available with the pro version that make the overall job easier and faster.

AutoCAD

AutoCAD (autodesk.com) has been around for a very long time, and it packs a lot under the hood. It’s most likely far more powerful than anything you’ll need for a tiny house design, but it’s a great resource should you decide to use it.

AutoCAD can be used to draw in both two dimensions and 3D. If you struggle with visualizing things in three dimensions, it might be easier for you to work in two dimensions instead. Because AutoCAD is such a well-known platform, many architectural programs allow you to import your 2D AutoCAD designs into its 3D simulator.

Pros:

• Very powerful design options.
• 2D and 3D design available.
• Interfaces with most other design software.

Cons:

• Perhaps overkill for your needs.
• Can be difficult to learn to use.
• You may need to create wall details from scratch, rather than importing existing details.

Home Designer Suite

Home Designer Suite (homedesignersoftware.com) is intended for conventionally sized houses, but you can use it on a tiny house design as well. It provides users with a questionnaire asking pertinent questions and generates a floor plan based on the answers.

With Home Designer Suite, you can view your 3D model from various angles as well as capture a video of the tour to share with others. One of the coolest features the program offers is the cost estimator. The program can create a spreadsheet with the cost of supplies you’ll need to build your tiny house. Though not 100 percent accurate, it will give you a general idea of what to expect.

Pros:

• Offers cost estimating software.
• Relatively simple design features.
• 3D design for easy visualization of the space.
• Questionnaire may be useful in triggering thoughts you might not otherwise have about the design.

Cons:

• May be more than you need for a tiny house design.
• Doesn’t interface well with other programs.
• Estimating software may not be as accurate as you would like.

SketchPlan

If you don’t need something quite as robust as Home Designer Suite, check out SketchPlan.com. By simply uploading your floor plan with dimensions formatted to their needs, you receive a polished computer generated substitute. You can even upgrade to a full 3D render of your floor plan, which allows you to take a virtual tour of your future home. The costs are very reasonable for this service, too.

Pros:

• Quickly generates 3D model for visualizing the space.
• Simple to use.
• Very reasonably priced.

Cons:

• You need to generate the 2D floor plan separately.
• Limited in its functionality and data representation.

Converting Your Designs into Architectural Plans

While having a floor plan—or a 3D version of your design—is a great starting place, it’s not the end. You’ll need to create what are called working drawings from the current plans. These drawings will contain a lot more detail about the actual construction methods.

DEFINITION

Working drawings are what you actually build from. They contain all of the necessary information to build the house including dimensions, material choices, layout decisions, fixture locations, cross sectional views, design details, and more.

For example, you’ll need to decide whether you’ll be framing your walls with 2 × 4 studs (16" o.c. or 24" o.c.), or perhaps using 2 × 6 studs. All of that information needs to be laid out clearly in the working drawings.

It’s all in the details, as they say, so the details need to be accurate. It’s important to show things, such as how the window framing details and trim come together. It’s also important to show construction details, such as the anchoring of the structure to the trailer. For better clarity, these details are typically done in a larger scale—¾" equals 1'.

You’ll want to create as many details and construction drawing pages as you deem necessary. Consider that taking time to draw the details is much faster than building them without fully understanding how everything comes together. It’s cheaper to erase mistakes on paper than in reality.

The Importance of Engineering

Engineering is essential on a set of tiny house plans, especially if the home is going to be on wheels. Engineering documents ensure that if all construction details are followed correctly, the tiny house will perform as expected and won’t pose a structural risk to you or anyone else. Because there are so many factors at play in THOWs, understanding how it all comes together can be difficult, even for a professional.

Licensed architects can provide their own engineering details on plans, but they often work with an architectural-specific engineer to ensure their numbers are correct. Designers, on the other hand, are required to subcontract all engineering work out to a licensed engineer.

TINY WARNING

Compared to conventionally built houses on fixed foundations, tiny houses on wheels suffer a much larger range of loads and stresses as they’re towed down the road. They must be able to endure earthquake-like movements, hurricane-force winds, and the stress of deceleration if the driver jams up on the brakes. It’s essential that your tiny house plans be reviewed by an engineer to ensure they can handle all of those loads and forces.

Wind Loads

Any residential structure must be designed and engineered with potential seismic-, wind-, and snow-load burdens in mind. Various technologies offer solutions to each of these challenges, even in tiny houses. Knowing which ones to focus on will help ensure you end up with a safe design.

We’ve all watched news footage of the damage tornados can cause to structures. The biggest concentration of this destruction is often seen in mobile home parks. That’s not because tornados have a personal vendetta against them, but because mobile homes are typically not designed to withstand high winds.

Mobile homes, now called manufactured housing, are more susceptible to wind damage because of their connection, or lack thereof, to the ground. Appendix E of the 2015 IRC addresses this issue and specifies requirements for setting manufactured housing on foundations. Because of this effort and improved anchoring, manufactured houses are resisting high-wind forces much more effectively today than in years past. By following the details of IRC Appendix E, or by using engineered alternatives, you can keep your tiny house safe in high wind events.

Tiny houses on wheels must also deal with excessive wind loads when being towed. Imagine driving down the highway with your brand-new THOWs at 45 mph. Wind is hitting your beloved tiny not only from the front but also from the left side at 50 mph as you near a storm front. Suddenly, an 18-wheel tractor-trailer passes you at 70 mph. Your poor tiny just got blasted with a hurricane-strength gust. You can practically hear it groaning. Knowing that your home has been engineered to handle these types of wind loads will help bring a sense of calm during a time of potential stress.

A Tiny House On Wheels (THOWs) being towed down the road is subjected to significant wind forces from various angles at any given moment.

Seismic Loads

Seismic, or earthquake, forces exert a different type of pressure on a Tiny House On Wheels (THOWs). When an earthquake occurs, a sudden release of energy travels on the Earth’s surface as seismic waves. Those waves move both vertically and horizontally, causing violent shaking to a structure as well as a side-to-side motion that can easily overturn a house.

In today’s residential housing codes, there’s nothing that recognizes THOWs, so all building science that discusses the need for proper anchoring is aimed at foundation-bound structures. Within those findings, the evidence is clear that foundation-bound structures must be sufficiently anchored in order to better protect the inhabitants during a seismic event.

We expect the same data to pan out for THOWs as well. As such, be sure to pay adequate attention to your foundation options and anchoring your trailer to the ground while parked. Even if you plan to move frequently, it’s still a good idea to anchor the home while not in transit.

Snow Loads

Though the white stuff looks pretty and fluffy as it’s coming down, it’s actually very heavy as it accumulates. While tiny house roof spans are small, they still must mitigate that weight in cold climates. In snow-prone areas, steeper sloped roofs are recommended over lower-sloped ones because they allow snow and ice to slide off more easily.

An important consideration when dealing with snow loads is rafter sizing. In a climate that’s warm year-round, you might be able to get away with 4" × 4" rafters (assuming they structurally support the span) at 24" centers. In high-snow zones though, that rafter size is likely not appropriate. Increasing rafter sizes in a THOWs is not simple because it translates to a decrease in loft ceiling height. Instead, you might be better off reducing the gaps between each rafter to strengthen your roof while not compromising your loft height. For example, move to a 12" spacing from the standard 24" o.c. layout.

Two feet of hard packed snow on a 28' × 8' tiny house weighs more than 6,000 pounds. If you framed your THOWs in Florida with rafters sized for that climate but now find yourself living the dream as a ski instructor in the Colorado Rockies, there’s a good chance you’ll come home to a pile of splinters after the first major blizzard if you don’t make some alterations to your roof design.

TINY WARNING

Snow is heavy and can cause a roof collapse if a house isn’t built to properly accommodate the load. Building codes for roof framing vary from region to region depending on snowfall and other factors. Check the building codes in the snowiest area you think you’ll visit with your THOWs to ensure it can handle those loads.

It’s essential you design your THOWs to best match future plans. If those aren’t clear, design the strongest and most versatile tiny house you can afford. This will give peace of mind not only to you, but also to any future homeowner that ends up moving the house to a different climate zone.

Additional Stress Loads

Imagine you’re towing your THOWs and are passed by a semi-truck traveling at 70 mph. As the truck passes you, you hit a pothole in the road. You just added an 8.0 seismic event for your THOWs to manage.

But wait, it gets better. We have another force to throw into the mix—deceleration. This is the force exerted on the house when you hit the brakes. It could be slow and gradual or dramatic depending on how hard you hit the brakes. Are you getting the argument for engineering yet? We hope so.

On top of all these tiny house specific stresses, there are two standard load paths that all houses must deal with—dead and live loads. Dead loads consist of the weight of permanently attached aspects of the home. Examples of dead loads are framing members, fixtures, and any other load that doesn’t change with time.

DEFINITION

A load path is the path through which loads pass from the highest point in a structure through the wall systems, floor, foundation, and eventually to the ground.

Live loads consist of any load that is not constant over time. Examples are movable furniture, people, snow loads, and the like. Each type of load affects a house differently, but they must all be considered in the design. Can you guess who can help you with that? Bingo! An engineer.

We imagine we’ve gotten you a bit rattled reading this section, so we want to reassure you by saying that these potential forces can be mitigated with proper design. Houses have been built to withstand hurricanes, earthquakes, and more for ages. RVs deal with these stresses on a day-to-day basis with pretty good success. Your THOWs will do great as well provided you plan accordingly. Be sure to include adequate bracing, anchors, connectors, and other construction details to your tiny house and it will stand tall and proud no matter what force comes its way.

Weight Distribution

Weight distribution in a THOWs has a huge effect on towing performance. Properly balancing the loads over the axles and from side to side allows for a smooth towing experience. A poorly weighted tiny house, on the other hand, can instigate dangerous side-to-side sway.

When designing your house, pay attention to how the trailer is loaded. If you place a heavy kitchen on the right side and nothing on the left, your house will be unbalanced. Adding too much weight in front of the axles (on the tongue side) can also cause weight distribution problems. Conversely, adding too much weight behind the axles can create a safety hazard, too.

TINY TIP

We highly recommend sway bars for trailers and tow vehicles for an extra safety measure. This after-market addition helps spread loads from the trailer to the tow vehicle’s rear axle, offering stability and control above and beyond a well-balanced trailer design.

If you’ve balanced your home properly, your dead and live loads will all be accounted for. You’ll be able to tow without any sway and will look and feel like a champ as you pull your tiny house down the freeway.

What Does This Thing Weigh Anyway?

As tiny housers, we sure have to deal with a lot of interesting challenges, one of which is knowing how much our house weighs before the trailer is even ordered. Because the strength of the trailer is completely dependent on how much the house on top of it weighs, you’d better have a pretty good sense of it all ahead of time.

If you aren’t purchasing a set of tiny house plans with this information, an engineer can estimate the weight using weight tables and charts. You can also find similar charts by doing a web search for “common weights of construction materials.” There are also books geared toward builders (not engineers) that outline material weights, too.

Large hardware stores offer the weights of all their construction materials as well as cabinets, finish materials, and the like, on their websites. Look under each product’s information page for those specifications. In terms of the trailer, contact potential manufacturers and ask them for that information. Your trailer weight will need to be factored into your total load estimate as well.

For a general sense, you can calculate a rough lineal foot weight. The industry standard for most wood framed 8'6" wide × 13'6" tall THOWs says that you can expect a weight of 400 to 600 pounds per linear foot, including the weight of the trailer itself. That’s a pretty wide range because there are lots of different finishes available.

We always recommend people err on the side of a larger-than-needed trailer than one not built strongly enough. Changing axles and increasing the strength of the frame is not easily done and once the house is attached to the trailer, it’s nearly impossible to remove that home in order to place it onto a new trailer.

The Least You Need to Know

• To make sure you consider all potentials, it’s best to start designing your tiny house by dreaming big and then whittling down.
• To maximize efficiency, each item you incorporate into your tiny house design should serve at least two purposes.
• Sometimes it’s easier to purchase a complete set of quality plans and make modifications to it than to start from scratch.
• Design programs have become highly sophisticated and can create beautiful 3D perspectives on your tiny house design.
• The best way to ensure your THOWs will be safe while in transit and when set onsite is to hire a structural engineer to review your plans.