Rustic guesthouse DIY build wrap-up, episode 4

The final Build episode in our second semi-trailer project (P2) is a progressive update looking at the evolution of the guesthouse bedroom and bathroom. Mike does the final major edits to the industrial space to reveal a beautiful view and an attractive space for him and Heidi to offer guests some comfortable hospitality!

Follow along to see how Mike achieves some of his affordable and creative solutions that you can apply to your own projects! This episode features the final touches on the bedroom space including a DIY murphy bed, some funky ceiling and detail finishing and a major overhaul of windows in the bathroom. All in time for some visitors!

Semi-trailer guesthouse build update, episode 3

The third episode in our second semi-trailer project (P2) is a progressive update looking at the evolution of the guesthouse bedroom. Mike aims to craft a space that belies the dark and unfriendly nature of this industrial container into a cozy guest quarters.Β 

Follow along to see how he achieves some of his ideas with affordable and creative solutions that you can apply to your own projects! This episode features the completion of the overall bedroom space, some funky ceiling finishing, easy-to-DIY cabinet-making, lighting tips and ensuite bathroom progress.

Our Top 5 interior design principles

Tips and Tricks: the Design Principles that we used for our semi-trailer home

To get the most out of your limited space in a tiny house, it pays to examine some specific design principles that will help you maximise the perception of your space. On the journey in building our semi-trailer tiny home, we focused on these main concepts. While our space is unique, there are many design principles that can apply to any tiny house or other small space. Let’s have a look at our Top 5!!

5 Pros and Cons to semi-trailer homes

What sorts of things should you consider when thinking about building your tiny house out of an ex-refrigerated semi-trailer? It is a great way to build especially for DIYers, but there are things to watch out for as well. Mike looks at his top 5 pros and top 5 cons for going this route for your future tiny home.

Check out the video at the bottom of this post if you’d rather watch than read πŸ™‚

The Surprising Pros and Cons of Building a Tiny House Inside a Semi-Trailer

If you’ve ever looked at a tiny house and thought, β€œI love it… but could I possibly have more space, more stability, and a little less anxiety?” β€” then let me welcome you into the peculiar, underrated world of the ex-refrigerated semi-trailer tiny house.

Heidi and I live in two of these gentle giants, and over time we’ve learned what works, what doesn’t, and what simply makes you smile and shake your head at your own life choices.

Here are the top pros and cons β€” the things you absolutely want to know before diving into one of these beasts.

The Pros: Why a Semi-Trailer Makes an Amazing Tiny Home

1. The Sheer Size (It’s Basically a Studio Apartment on Wheels)

It still surprises people when they step inside. A typical refrigerated trailer is around 12–13 metres long2.5 metres wide, and 2.7 metres high inside. That gives you a huge rectangular canvas β€” no odd angles, no quirky rooflines, no sloping ceilings designed for hobbits.

Just… space.

Space to design.
Space to breathe.
Space to spread out your tools and pretend you know exactly what you’re doing.

And when you’re building a tiny home, that simplicity is priceless.

A person pointing towards a modified ex-refrigerated semi-trailer tiny house, showcasing its green exterior and window

2. The Price (Yes, Really)

This is where semi-trailers quietly destroy the competition.

Our two trailers cost $10,000 total β€” that’s 64 square metres of ready-made structural envelope for less than the price of a bare tiny house chassis.

Walls, roof, floor, frame β€” all done.
Made from fibreglass, steel, and aluminium built for endurance.

In tiny-house-land, that’s a unicorn-level bargain.

Two ex-refrigerated semi-trailers converted into tiny homes, situated in a grassy area with trees in the background.

3. The Ease of Building (A First-Time Builder’s Dream)

The joy of building inside a semi-trailer is that the structure is already doing the heavy lifting.

Want a door?
Cut the hole, weatherproof it, pop the door in.

No structural framing.
No load-bearing walls.
No engineering anxiety about whether that cute light fixture secretly weighs as much as a small goat.

Inside, weight restrictions vanish. Marble benchtops? Concrete floors? Go wild.

It’s the closest thing a DIY builder will ever get to playing a life-sized version of The Sims.

A person using a circular saw to cut the exterior wall of a semi-trailer while standing on a yellow ladder, wearing safety gear including headphones and a dust mask, against a backdrop of partly cloudy blue sky.

4. Road Safety and Stability (A Heavy Beast Is a Safe Beast)

A semi-trailer is built to carry 35 tons at full load, cruising down highways like it’s nothing.

So your tiny house ends up with:

  • Airbag suspension
  • Massive wheels
  • A bulletproof steel chassis
  • Remarkable stability in all weather

Compared to towing a lightweight tiny house, this thing is a zen monk rolling down the freeway.

A semi-trailer converted into a tiny house, parked in a grassy area under a cloudy sky.

5. No Loft Living (Depending on Who You Are, This Is Glorious)

Some people love lofts. Some people love not smacking their head at 2am because they forgot to duck.

We chose single-level living: high ceilings, no ladders, no crawling into bed like a tired cat.

We even installed a lift bed to reclaim floor space when needed.

Interior view of a tiny house built inside a semi-trailer, featuring a kitchen area with blue cabinets, a refrigerator, shelves with dishes, and large windows allowing natural light.

Bonus: Giving Industrial Waste a Second Life

Each trailer is around 15 tons of metal and fibreglass. Most end up rusting in paddocks.

Repurposing one is an act of quiet environmental kindness β€” rescuing literal tonnes of material from landfill and turning it into a home.


The Cons: What You Need to Know Before Buying One

1. You’re Building Inside an Old Vehicle

Let’s be honest β€” these things spent their lives hauling frozen goods across Australia.

Expect rust, dents, roof repairs, bowed walls, and strange angles that test your patience.

The cheaper the trailer, the more quirks you inherit. You’re buying character… sometimes more than you bargained for.

2. It’s… a Big Box

If you dream of a tiny cottage with a pitched roof and storybook charm, this may not scratch that itch.

Semi-trailers are functional rectangles. You can beautify them, but they’ll still be rectangles with a very practical past.

An ex-refrigerated semi-trailer converted into a tiny house, showcasing its rear view with closed doors and a simple wooden staircase leading up to its entrance.

3. Flat Roof = No Easy Rainwater Harvesting

The flat roof simplifies building but complicates water collection.

If you’re off-grid, you’ll need a false roof, angled structure, or separate catchment setup. Skylights can add another layer of complexity.

A flat roof of an ex-refrigerated semi-trailer

4. The Monster Tires

Six per trailer. Twelve total. Each one is $1,000 new or about $100 used.

They elevate the house beautifully and give great under-floor access, but they also age, crack, and occasionally explode at inopportune times.

A person inspecting the tire of a semi-trailer, highlighting its size and condition.

5. Moving Isn’t Something You Do on a Whim

To move a semi-trailer tiny house, you need:

  • A heavy-duty truck
  • A driver
  • Scheduling
  • A little luck

You can’t just hitch it to your family ute and head off. If you ever need to move quickly β€” bushfires, land issues β€” it takes planning.

Final Thoughts

Semi-trailer tiny houses aren’t for everyone, but they’re incredible for the right person.

If you value space, stability, affordability, and the satisfaction of upcycling a multi-tonne industrial relic into a cosy home… this might be the path for you.

I hope this guide helps you think through your options. If you want to explore your own ideas or run designs by someone who’s made all the mistakes already, I’m always happy to help.

P2 progress: Rendering, window and toilet

Progress of the transformation of our second semi-trailer has happened in fits and starts, but I’ve seen some real transformation with our bedroom and bathroom areas. Slowed by factors like economic issues, the silly season and focusing on other business ideas, things haven’t been chugging along as I’d like, but sometimes the foundational work appears to be slow. Slap a coat of paint on something, implement a final component and suddenly you can gain inspiration and motivation with where the project is going.

My second video instalment in the building update of this second semi-trailer attachment (P2) to our main home (P1) (whose build I covered in an extensive video series between 2019-2022) shows some significant aesthetic changes from the original tour video I did of P2 in which I had already jumped ahead with some of the work I had done to form the basis of this new phase of building. In that sense, this video series will be far less comprehensive than the original P1 series as I started this project with no interest in filming it and then of course regretted that when I decided it would be a cool idea. Lesson learned: just film some stuff anyway…you can always just ignore/delete it if you don’t need it.

Anyway, here’s Episode 2! Thanks for watching and being a part of the journey β˜ΊοΈπŸ’šβœŒπŸΌ

The Perils of living in a house on tyres

Do tiny house tyres explode? Unlike some tiny houses which live on small trailers and get propped up off their tiny wheels when parked, it’s a bit different with our semi-trailer home.

In this short video, we respond to questions of how durable our tiny home tyres are and how we have prepared for their support and maintenance. Enjoy and thanks for watching! πŸ’š

A new start: our second semi-trailer project journey begins

the.semitrailer.project.P2 : : Build update – Dec 2023

A new chapter with a new semi-trailer project! This overview tour gives you a sneak peek at progress to date of the second half of our semi-trailer tiny home. Mike discusses what we’ve completed and future plans to come for this guest space, storage area and fancy bathtub room ☺️

With this new chapter, we hope that you find inspiration and creativity for your own project and minimalist vision. Enjoy and thanks for watching! πŸ’š

The FINAL house build video packed with goodies! Moving Day for our tiny to its new location

the.semitrailer.project : : Build update – Oct 2022

day 1317  : :  blog post 024

There was just too many fun projects left to finish, so it warranted this final jam-packed episode en route to us moving the tiny to its new permanent location. The clock was ticking to wrap up the last of the tiling, plumbing, flooring and many other little tasks before our Big House on Wheels (BHOW) was hitched onto the prime mover that took us to the outskirts of Adelaide.Β 

Our 3 year journey is wrapping up…thanks for being a part of it! Enjoy and thanks for watching! πŸ’š

A sneak peek inside our temp home for over 2 years, another semi-trailer called P2

the.semitrailer.project : : Video update – Oct 2022

day 1315  : :  blog post 023

As we roll down to the end of this series, join me as I expose our little unfinished shack (lovingly known as P2) to the world. This video might not interest many folks, but while we built out tiny house, we glamped in this unfinished semi-trailer. So this is more of a reminder for us about our old home but you might be curious as well. Enjoy and thanks for watching! πŸ’š

Finishing flourishes, cool homemade composting toilet and a change of scenery

the.semitrailer.project : : Build update – Feb 2022

day 1067  : :  blog post 022

One of our last episodes (did I say that last time??) πŸ˜›

Who doesn’t love getting close to the finish line on a build? It’s when we get to finally add the pizzazz like knobs, trim, lights and appliances. Throw in a unique homemade composting toilet solution, and we have the makings for a party! In this episode, Mike gets close to wrapping up a few areas and you get to see more of what all the fuss was about over this series. Poor withering Mike is also reaching the end of his stamina for house building!

Enjoy and thanks for watching! πŸ’š