The exterior of the tiny house has (mostly) been complete for a few months now! I relied a lot on information from other people within the NZ tiny house community, I know how valuable it is to share experiences. I’m often asked about my build and the materials I chose to use, so I’ll share a breakdown of what was used for the external shell.
We all know I love upcycling, reusing, and diverting things from landfill. So you would expect that my tiny house build would use all reclaimed materials, right? I’m meeting in the middle and using a combination of reclaimed and new materials. While reclaimed materials are low cost, sustainable and interesting, unfortunately, they also require a bit of time and skill to make it work. Even though I’m building my tiny house myself (with a bit of help from friends and my Grandad), I really don’t have any practical skills. I am learning along the way, but upcycling takes a certain skill level I don’t possess. The other downside to reclaimed materials is they take a lot of time to make useable. The tiny house build is not a full-time project and I currently don’t have somewhere for it to stay long-term, I need to save time where I can. I mentioned in my previous tiny house blog post, that due to my lack of building experience, I am making easy building choices, which is why I have chosen the following materials. I’d also like to point out that I am in no way affiliated with any of the companies mentioned below, these are the companies I chose to go with after extensive research and recommendations.
My Tiny House External Materials
The trailer is usually the first thing one buys when going tiny, and it’s also the most expensive thing! I did quite a bit of research into trailers for this reason. Eventually, I chose a local manufacturer, Pinto, a well-known trailer company in New Zealand mostly known for their horse floats. I chose Pinto as they were in my local area, affordable, and had been recommended by other tiny housers. Also, they support Project Jonah! I did see a considerable number of recommendations for Bay Engineering, but I chose to go local mainly for logistical reasons (I don’t have a vehicle to tow my trailer haha). My trailer build took 4 weeks, costing just over $10k (including road user costs).
I chose steel framing for a few reasons.
- It’s lightweight
- It’s easy to erect
- Best framing for a vehicle (cause the tiny house is technically a vehicle)
- Quick to install
I got my framing from local company FrameTek who made the frames and delivered it on the same day, such a small job for them! The framing took my friends and I a weekend to erect. A professional would be able to do it in half a day. Steel framing costs more than wood, but for me, the benefits out-weighed this. My main issues with the steel framing are having to screw everything, as opposed to just using a nail gun/staples, and spacing is not at 600 even.
I chose to get a thermal break to help with preventing thermal bridging between the cladding. I got the thermal break sheets, that were supplied by FrameTek. Unfortunately, these are polyester, and I’m not sure if they can be recycled. I found the sheets quite difficult to work with, they snapped easily and there were a few casualties due to even the slightest breeze. The sheets were glued to the steel framing. In retrospect, I would have used a cavity batten with a thermal break, such as this.
My original plan was to clad the tiny house in corrugated iron. I love the look of weatherboard but knew I did not possess the time, skills, space or tools to install. Corrugated iron and shadow-clad were both easy cladding options, as they come in full sheets. Corrugated iron is light-weight, easy to source and install and affordable. I decided to add in shadow-clad to break up the iron and give my tiny less of a shed look.
I bought ‘seconds’ shadow-clad from a supplier in Hamilton. The sheets were cheaper as they had strapping tape marks on them, which doesn’t bother me. I plan on staining or painting the wood to help extend its life. I’m currently undecided as to which, so let me know your thoughts on what is better- painting vs staining.
The corrugated iron was a combination of second-hand colour steel (from TradeMe), and new ‘downgrade’ offcuts from my local corrugate manufacturer, Dimond. The downgrade corrugate cost $20 per 2.4m long, new corrugate is about $20-40 per metre, so this was a decent cost saving. The pieces are exactly the width of my tiny house so this worked perfectly for the short sides. As I was buying downgrades, this meant I did not have much of a colour choice, I had to choose what was available. There are 6 different colours of iron, including the roof, and only 1 panel that is randomly mismatched (on the back). Again, it really doesn’t bother me.
I used the plastic CaviBats for the cavity between the building wrap and cladding. Cavities help with air ventilation for moisture control. I chose the plastic CaviBats as they are lightweight and came recommended by other tiny housers. Honestly, these things were so hard to use with steel framing. With timber framing, you can easily use a nail gun to secure them. Screwing these into the steel framing was time-consuming and frustrating. I mentioned before that retrospectively I would have used a thermal break CaviBat, but actually, timber cavity battens would have been ideal (with a thermal break still). CaviBats are 100% plastic and are recyclable. Environmentally, these were a bit of a nightmare, as it was so hard to capture all of the micro-plastic! I actually vacuumed these before using, recycling the microplastic in a container of the same plastic type. The off-cuts were mostly all used, and the remaining amount I had was sold on TradeMe, to another family building a tiny house. Any non-usable amounts were recycled.
The building wrap was purchased from the same place as my shadow-clad, it was ‘seconds’ purely because it had random branding on it. It was still functional building wrap. I ended up running out in the last 3 meters (doh!), fortunately, my grandad had some spare building wrap kicking around his basement.
I went with metal roofing due to weight and ease. I bought my roofing from Dimond, purchasing brand new roofing and flashings. The place I got my flashings from also chucked in a free box of roofing screws, as the guy had no use for them. This saved me a small fortune, and there were enough to do the whole roof, and they even matched the colour of my iron! The roofing paper I used was another one that my Grandad had in his basement, I was very lucky to have Grandad’s old building supplies as a resource!
Windows & Door
The windows and door were the second things purchased, after the trailer. To save money I purchased second-hand windows before having my steel framing made. This meant I didn’t have to have new or custom made windows. All of the windows and the door were purchased from Demolition Traders in Drury. I have visited quite a few demo yards now, but have found this one to be one of the better ones. Some of the windows needed the wooden sills replaced, my builder Grandad did this for me. Two of the windows are fixed (i.e. not opening), saving on costs and because that’s all I could find in the yard on the day. The windows and door cost about $1700 total, which is pretty cheap for windows. The cat door was also an early purchase, as I stumbled across it at the Waitakere Transfer Station Recycle Shop. My cat is 11 years old and of all the rental properties we’ve lived in together (about 7!) I’ve never had a cat door, so this was a must! The little frame around it was custom built on a CNC machine using scrap wood.
The utility/storage box at the front was built last, using timber framing and leftover shadow-clad and corrugated iron. This will house my solar batteries (hopefully) and bit & bobs.
Tiny House Update:
The tiny house exterior was built part-time over about 3 months, with the help of my friends and my Grandad, who is a builder. My Grandad was reluctant to help out, as being a traditional builder he would rather I buy an actual house and build with timber. The steel framing proved to be particularly frustrating for him, having never worked with it before, and with it being less forgiving than timber.
I am extremely grateful for all of the help my friends have given, some of them have practical skills, and many more learned how to use power tools during the process. I should also add, that all of the power tools I’ve used were borrowed! I feel very lucky to have had access to tools and help! I wouldn’t have gotten this far if it wasn’t for my Grandad though, who came and helped out despite telling me not to build a tiny house! I decided to name my tiny house Earnie, short for Earnest, my Grandad’s middle name. Earnest also felt like a very fitting name for such a small house.
The build has cost about $25,000 dollars to complete the exterior shell. I think I’ve done pretty well, considering the trailer cost $10,000 and steel framing was another $6000 ish. It could have been cheaper, but there’s those time/money trade-offs.
Currently, I am planning the technical stuff on the interior- plumbing, wall lining, electrical and the off-grid setup. This has caused me a delay, mostly because I don’t know what I’m doing and am researching heaps. I don’t have a deadline or time frame for my tiny house build, but considering I’m paying rent and flatting while building, it would be nice to actually get into my house sooner rather than later. And I’d like to finish before the landlords decide they really want it gone! I’ve been pretty lucky that they have been so tolerant of the build, but they have asked when it will be moved… If anyone in Auckland thinks they can help me in any way, feel free to get in touch with me here or email (firstname.lastname@example.org). Ngā mihi!
All of my tiny house blog posts can be found here.
I also recently wrote this article for This NZ Life: