Introduction: Tiny House Series: Pt. 1 Exterior

About: Trask River Productions is a non-profit vocational education woodshop ran through Trask River High School, which is in turn located inside of a Youth Correctional Facility in Tillamook, Oregon.

We at Trask River Productions are building a tiny house! We had great success with our tear drop trailer last year, so this year, we stepped things up a bit and started a tiny house. Due to the enormous task of building a tiny house, we are going to break our instructable down to 3 separate steps;

1) Exterior

2) Interior

3) Furnishing/Finishing Touches

This instructable is the first step of the process, the exterior. Subscribe for automatic updates when we post the next part of our Tiny House Series.

As you will see in some of the instruction photos, we had to blur the faces of some of the people in our instructable. Trask River Productions is a vocational education program ran through Trask River High School, which is in turn located inside of a youth correctional facility. This leads us to confidentiality laws and prevents us from revealing the identity of any of the youth in our program.

With that being said, let’s begin.

Contest info: We are currently entered in the Epilogue contest, so if you enjoy our project, please vote at the top of the page. If we win first place, the laser engraver will be put to use in our program and provide our at-risk youth the opportunity to learn some new skills that they could possibly use in their lives as a career choice. Regardless of the contest results, we hope you enjoy our project as much as we have enjoyed building it.

Step 1: Introduction

This instructable is not meant as a perfect guide to building your own tiny house. I am not including detailed blueprints of it, nor am I providing very many measurements. Every tiny house should be built custom to the owner’s own preferences. I am however providing detailed steps and photos of the tiny house we built. I am hoping you are interested in building your own tiny house and will use my guide as a start for designing and building your own. The internet is crawling with other designs for a tiny house, and you can find just about any plans you would like to with a simple search engine. I am going to use layman’s terms, so people without any experience can follow along and not struggle with concepts and lingo. With all that being said, I hope you enjoy this instructable almost as much as we enjoyed building the instructable.

Another not is we are not going to provide an exact list of materials; however, we can help guide you in the right direction with our steps in the process and our rough material estimates.

Update: We expect to keep the total weight under 11,000 lbs. The tandem axle trailer is rated at 14,000 lbs and is custom built by a local trailer manufacturer, designed for a tiny house build. This tiny house can be towed with a 3/4 ton or 1 ton vehicle. It also comes with electric brakes and tail lights.

Step 2: Materials


Tiny House pre-made trailer from Iron Eagle trailers. (Or you own choice of trailer)


½” CDX Plywood Sub sheeting for the walls

2” x 4” Framing boards with 16” spacing on center

15lbs felt for sides between the CDX and Breckinridge plywood

3/8” Breckinridge plywood siding sheets

Our siding was primed and painted before we hung it.

1” x 2” clear cedar bats for siding, spaced every 16 inches on center

Windows / Door

(All the windows are white vinyl clad windows)

1 8’ x 4’ fixed window (Front center)

1 4’ x 2’ fixed window (Front Top Center)

2 4’ x 2’ opening windows with screens (Lofts)

2 3’ x 2’ fixed window (Front Top Middle)

2 3’ x 2’ opening windows with screens (Back Windows)

1 2’ x 3’ frosted opening window with screens (Bathroom)

1 2’ x 3’ opening window with screen (Kitchen)

1 3’ x 6’ 8” Exterior door, (fiberglass clad, 6 panel door, with obscured glass on the top)


2” x 4” Framing boards with 16” spacing on center

½ CDX sheeting for roof

30 lbs. Felt Sheets

12” standing seam metal roof, repainted, trim and caps


2” x 4” Framing boards with 16” spacing on center

R-30 value foam insulation for floor

¾” Tongue and groove ply subfloor


Exterior Strength Calking



Assorted Nails

Assorted Screws

Step 3: Level the Trailer

To build a house, you start with a base, and in this case, the base is a trailer. While you can use just about any size and design of trailer, I would highly recommend purchasing a trailer from Iron Eagle, in Gresham Oregon. The trailer was perfect for our design, and it even has an inset pan to protect the floor insulation from the elements. If you cannot purchase a trailer from Iron Eagle, then I would recommend, purchasing a trailer that is built specifically for a tiny house. We went with a 24 foot long trailer. Our width is no more than 8 foot 6 inches at the maximum point, and a maximum height of 12 foot 6 inches so can keep it road friendly. Anything over these will require more permission and possibly a temporary permit to move on the road.

Before you can start your build, you need to start with a level trailer. Ours has leveling jacks; however, we wanted to do something more stable for the long run, so we used wood blocks. Using a car jack, we jacked up the high side of the trailer and placed wooden blocks underneath the corner of the frame. Once the high side was where we wanted it to be, we continued with the other 3 sides. It will take a little bit of time to level the trailer, but in the end it will be worth it. No one wants their house to have un-level aspects to it, and building on an un-level surface will do that.

Sorry I don't have any more photos of this process, I hope you are able to understand the process without photos. If you have any questions, feel free to comment and I will answer them.

Step 4: Adding the Subfloor

To begin your tiny house, you start with the floor. So adding the floor joists is the first step. As the trailer is pretty square and now level, it’s pretty easy to do this step. Simply cut the 2x6 boards to go around the inside of the pan for the floor, to the outside of the wall. This will give the other joists a place for them to attach to other than the metal trailer. Use bolts, nuts and washers to secure the boards to the wall.

Once the outside edges are attached, it is time to put the center floor joists into place. The trailer is short enough wide that you can run single boards across the width of it. Using 16” on center, attach them with floor joist ties to ensure stability.

Once all your floor joists are in place, start to insulate between them. You can use any kind of insulation, but we went with solid foam insulation with an R-30 value. This way if water happens to leak into the pan, the foam will hold up more than fiberglass will as far as mold or mildew goes, it’s also a lighter material and helps keep the overall weight down of the tiny house.

Once the insulation is in, use a caulking gun and caulking along all the 2x4’s and start to lay down the ¾” Tongue and groove ply subfloor. Make sure your seams are not on the same floor, so stagger the sheets so there is no solid seam down the length or width of the trailer, a seam would take away from the strength and solidity of the floor. Use nails to attach the plywood to the 2x4s, and a chalk line would be a good idea to make sure your nails hit the boards in the center. Before nailing down the plywood, use liquid nails to make a more secure bond.

Also, be sure to leave the width of your wall on the outside of the plywood floor. For this, we created a jig as you can see in the photos. The wall frames are going to attach directly to the trailer frame, so we don’t need the floor underneath the walls.

Before you finish the whole subfloor, be sure to leave an open space by the bathroom for the plumbing. We left the whole front of the trailer unfinished when it comes to the floor. So no insulation, or calking, but it is okay to cut the plywood subfloor and lay it down, just don’t attach it down until the plumbing is done in the next instructable.

Step 5: Building the Walls

This is probably the most important part of building the tiny house. By now you should have your plans finalized and ready to begin building.

Just like when you frame a house, we are building our walls flat on the ground, standing them up and then attachment them together. We started our house with the back wall, as well as the back side wall. This gave us the chance to attach the walls together for a support; no one wants their wall the fall down as they are making it. This is where it is very important to have your final design and build plans all laid out. This includes your windows and any doors you might include. As well as the knowledge of what kind of siding you are going to use and the measurements of it. This will allow you to have a stud to attach any seams of your siding together. But don’t worry too much as you can always add another stud for the plywood seams to attach to when you need to.

When framing your walls, use a measuring tape and speed square so you know that your walls are square and will be level this way. The trailer should be level already, so making your walls square will insure that they also remain level. There is probably going to be some degree of error where it is not perfectly square or level, but you should still try to get it as square and or level as you can.

Be sure to use proper framing methods when framing around windows, and doors. Remember that every window should have a header and cripple to support them. If you are unsure of some of these terms, use a simple Google search to understand how to properly frame a house. If you are using a blueprint or building plan, then you only have to follow their design, another benefit of using one.

If you are still unsure of where to start with your frame, I hope these photos will give you some clue on where to begin at. This is the part where I am not going to include measurements, but you could figure it out with your own designs and our photos.

When building the walls, all 2x4’s should be spaced 16” on center apart. This provides the proper amount of support, and is spaced perfectly for 8’x4’ sheets of plywood.

Because the front of the tiny house, as well as the back of the tiny house are exact mirrors of each other, we can build them on top of each other so we know they are the proper size and angle. The only difference will be the windows as the front of the house is the bathroom and there is only one window in the center; while the back of the house is the living area and there is two windows.

After all the 2x4s are nailed together in their correct placements, we start attaching the CDX plywood. The 2x4s should have window and door holes framed into them. For the front and back of the house, leave a ½” of plywood hanging off the edge of the wall. This will become flush with the plywood of the other wall and give a nice finish. Refer to the photos if you unsure what I mean.

For the windows, when it comes to attaching the plywood to these sections, simply nail the plywood down over the window holes. Then after the plywood is nailed down securely, using a drill, drill a hole from the inside of the window holes to mark each corner, draw a line to connect them together, and use a power saw to cut the holes out. This will ensure that the plywood fits perfectly together.

Remember that the end walls should be higher than the side walls to compensate for the height of the roof. Because the roof is framed with 2x4s, and has a ½” plywood, the side walls should be 4” taller than the side walls. (2x4s are not actually 2x4, but rather 1 ½” x 3 ½”)

After two walls are cut out and ready to go up, get a couple friends and/or family to help you raise them and attach them together. We started with our front wall and the door side wall of the trailer. Be sure to use temporary braces made from 2x4s to hold the wall up until it is all attached together. We left the braces attached until all our walls were attached, and I would recommend doing the same thing for safety reasons.

Continue raising the walls until they are all raised up and attached together. If your design is anything like ours it’s going to take a little bit of time and some patience.

After your walls are all attached together and covered with the plywood, the roof is the next step in the process.

Step 6: Building the Roof Frame

After all your walls are up and covered in CDX plywood, it is time to start building the roof. Every design of tiny house will differ with how the roof is built, but it’s pretty straight forward for every design. Every design should include a slope for rainwater and possibly snow to run off. A tiny house with a flat room will hold the water and or snow and cause structural problems. I have seen tiny houses with a double sloping room, almost like an A-frame, which is great for rainwater and snow to run off. However, you lose a lot of room inside, especially on the lofts. So we used the design of one single sloping roof. This gave us plenty of room inside of the tiny house and especially the loft, as well as providing the slope for the rain and possibly snow to run off.

To begin your roof, make sure your walls are done completely. Your frame should have two 2x4’s already on the top of the walls, so the roof will attach to both of them, using hurricane ties to hold it down in place once we are to that step.

The 2x4s should run the width of the tiny house, so using big enough lumber is a must. I believe 10’ 2x4s will work, as it did in our design, but it depends on your actual designs.

To attach the 2x4’s, simply rest them on the top of the wall frames, and attach them with a hurricane tie using nails. Simple enough right? Told you it was pretty straight forward.

The 2x4 boards should be space 16” apart on center again. We started with the boards on the back of the trailer and moved towards the front of the trailer.

On the ends of the tiny house, there should be a 10” overhang for rainwater, and to add to the overall design. We would add one to the sides as well, but we have to keep the whole house to under 8’ 4” to keep it street legal without any extra permits.

The final step is to cut 2x4 lengths to fit between the long beams of the roof. They go at the high and low sides of the roof to seal it in even more. I don’t have any actually photos of the process, but you can see it in the finished product photos. They provide a barrier for the outer plywood to attach to.

Once all the 2x4’s are in place, it’s time to use the plywood to cover the top of the roof. Be sure to stagger the seams and always have seams line up on the middle of a 2x4 so there is support for both sheets of plywood. The benefit of spacing the 2x4s every 16” inches is that the 2x4s will line up for every seam perfectly, making it a lot easier to attach the plywood.
I apologies for the lack of detailed photos for this step. It was a little hard to climb on the roof and take photos while the roof was being build and the ladders were in use. I hope the photos that are included do provide you with enough detail though.

Step 7: Sealing the Roof

To seal the roof, we used 30lbs felt paper. To lay down the felt paper, start at the bottom of the roof and unroll the paper along the length of the roof. Be sure to leave a couple inches of extra along the edge of the roof, we can always cut away the excess when we are done. Starting at the bottom, slowly layer the paper strips overlapping the bottom ones as you work your way up the house. Be sure to leave a couple inches of overhang to prevent water from leaking under the paper. Attach all the paper with a hammer stapler.

Step 8: Attaching the Metal Roof

Now for a tiny house, there are many different ways to finish the roof. I have seen many of them myself; tar or wooden shingles, metal sheets, even a plastic composite shed roof style. Because we are going to be moving our tiny house, we didn’t want to do tar shingles, as they wouldn’t stand up very well against the wind going down the interstate. So, we decided to go with a metal standing-seam roof.

A metal standing-seam roof is a very simple roof to install and works a lot faster than tar shingles would. They also have the benefit of allowing you to get them painted. The downside is you have to custom order them and it takes a couple days to get them.

The first step is to attach the lowest side of the roof’s metal flashing sheet. This seals the end of the roof, most of the flashing tucks under the main roofing metal strips, but it’s still a necessity. We use a different step for the top of the roof, so this is only applied to the bottom of the roof.

Use screws or nails to attach the metal flashing down, I would recommend screws, but nails would also work.

Next, start on one side of the roof and slowly work towards the other side, attaching the metal strips. Each strip of roofing covers the screws or nails from the previous sheet, so they provide a wonderful barrier against any rain or snow.

Because you had to custom order your metal roof, it should be perfectly sized to reach directly across the roof with no extra gaps or metal.

After the main roof strips are screwed down in place, attach the flashing for the ends of the roof, they might need to be cut to size as they usually are sold in long sheets and not custom made.

The final step is to apply the flashing at the top of the roof to keep the rain water from getting under the metal roofing.

Step 9: Installing Windows

Installing the windows and door is a pretty fairly straight forward process. Our window frames should already be cut and sized correctly for our windows so this step is simple enough.

Before we can install any window, we need to first prep the hole with an ice and water shield. This will help keep the wood free of any moisture that would mildew or even rot the wood away. The inside of the window hole needs to have this barrier attached to it with staples. Look at the photos for an example.

Once the barrier is in place, it’s as easy as putting the window in the frame, and nailing it in. Be careful not to hit the glass or vinyl frame either. Use any shims you need to keep the window centered in the frame and as level as you can get it.

Step 10: Finishing the Outer Walls

Before you can attached any siding to the walls, you’ll need to cover the walls with the 15 lbs felt paper. This will help provide a waterproof sealing if water leaks through the Brackenridge siding. Run the strips horizontally across the trailer, and be sure the overlap the layers of felt. Do the bottom first, the each layer above that will cover it as you work upwards to the top of the walls. Use a hammer stapler to attach the felt paper.

Before hanging the Brackenridge siding sheets on the wall, we need to primmer and paint them. This insures that all edges of the siding are thoroughly painted, again protecting them from any water damage. Be sure to use an exterior grade paint and primmer.

The next step of building the walls is to attach the Brackenridge siding on top of the felt paper. Use nails to attach the sheets to the 2x4 studs. We are going to hide the nails with the cedar bats, so be sure to nail the nails on a straight line and spread 16 inches apart. Start the edges of the sheet at the bottom of the walls, just past the bottom of the trailer so water runs off the wall and off the trailer instead of back on the trailer edges. As the sheets are only 8’ tall, we will need to attach more at the top to complete the wall.

Before doing that we need to install the metal flashing to prevent water from flowing into the top seams of the siding. Once the metal flashing is secured into place on the top edge of the bottom sheet of siding, you can finish hanging siding up on the walls.

Paint and primer the cedar bats and attach them to the trailer. This is a finishing step, so use a finishing hammer, and be careful not to over nail them and damage the bats in the process. The bats should be spaced 16 inches apart on center, and covering the nails used to hang the siding up.

Step 11: Calking and Trim

The final step is to trim the windows and door with some clear cedar for a finished look. Before adding the trim, be sure to primer and paint the trim. We used white in our house and gave it a nice touch to the overall aesthetics of the tiny house. Use whatever size of boards you prefer, but we used a 4” wide board for our trim.

Before you can nail the trim in place, use an exterior strength calking and seal up the seams all the way around the trailer. This includes the windows, soffits, and even the seam around the roof and walls. If you don’t use calking it, you can almost guarantee there will be water damage.

In most places the calking is going to be covered so do not worry about it looking perfect, but rather worry about it sealing well. In the areas that the calking will be seen, do your best to make it look even and clean. If you prefer there are tools sold to help you with the process, ones similar to a putty knife.

Final step is to nail the trim in place. You can use whatever size of trim you would like, in any design you would like, but most certainly use a small finishing nail.

Step 12: Installing the Door

Now comes the part where it begins to feel like more like tiny house and not a glorified shed, installing the door.

The frame should already be there, so it’s a simple matter of putting the door in the frame, leveling it out with shims, and screwing it in place. Before you start attempting the push the door into place, take 4 small plywood screws, and screw them to the outside of the door frame. This will save you countless moments of frustration attempting to adjust 3 parts of the door at the same time. Once the plywood is attached like in the photo, all you have to do is push the door forward against the plywood and it will keep it nice and flush.

Move the door to inside of the tiny house, and dry fit it in the frame to make sure it fits as planned. When fitting it, expect a large amount of space around the outside edges, something close to 1”-2”.

Once you are certain your door fits, use a calking gun and apply a generous amount of calking to the bottom of the door sill where the door is going to sit out. This will provide a water barrier to keep water from running under the door and ruining the flooring.

Now fit the door in place and start using the shims to get it located in the right position. Eventually you will trim the shims down, so don’t worry about them sticking out. Use multiple shims to get the perfect balance you are looking for. Remember to push the door to the outside of the trailer, as the four plywood guide you attached should prevent the door from going too far forward.

The door should open easily, and not close or open by itself. A perfectly balanced door will stop moving open or close when you take your hand of it. Because we leveled the trailer before we started, this should be the main goal of installing a door. No one likes a door that closes itself or swings open by itself.

The door should have a trim/seal inside the door that is removed to reveal the place where the screws go. Be sure to screw it in there as you will cover it with the trim/seal to hide any unsightly screws.

After the door is installed, it’s time to spray a foam insulation into the gap between the door frame and the 2x4 frame. The foam expands a lot, so don’t use too much. If you accidentally use too much, simply sand the foam flush with the door after it’s dried, and don’t worry as the final trim will cover it up.

Finally, install the door handle and lock.

Note: If you plan on installing any large appliances such as 1 piece shower and tub like we are, I recommend putting them inside of the tiny house before installing the door, it will make it a lot easier than trying to fit it through the door after it's installed.

Step 13: Final Thoughts

Now that you have your tiny house’s exterior complete, it’s time to begin the fun parts, the interior. Because I broke our tiny house instructable into a multi-part series, stay tuned for the next step in the process, the interior work. We are about half way done with our interior and will begin publishing our instructable soon. So follow us to receive instant updates when we have posted the next instructable. You can also go to our website and view our gallery, view other projects, or even subscribe to our mailing list. We update our tiny house gallery every step of the way and are constantly showing off the progress we have made. You can view our website at

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