WikiHouse in Imperial Units?

Hi There, I’ve been very excited to learn about WikiHouse - what a great concept!

If I were to start a pull request for an imperial version of the Skylark blocks (for North America), would we be able to merge it into the main branch? Or should I start it as a separate project?

The Skylark 250 blocks are close to 24” on center, and I could imagine a 16” on center version to work with standard construction materials

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Hi @stefan-webb. Good suggestion! I think a separate branch/project for now is probably the right approach, as it’s essentially a fork of Skylark and may well need it’s own (North American) bird name.
In terms of the 24" versus 16" set out, it’s worth finding a balance between standard construction materials available locally and the dimensional size of the plywood/OSB structural sheets (which I believe are generally still 8ft x 4ft in the US?). Other people have also raised the idea of creating a Skylark version for 3/4" plywood (~19mm), whereas in Europe the standard is 18mm.

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I’m just learning about wikihouse but agree that an imperial version would be appealing for US based construction. I’m interested in learning how I can help with the conversion – let me know if you decide to make a fork and are looking for help.

@ivy4cat Glad to hear you’re interested too! I investigated converting a basic wall block to something that would work with standard rockwool insulation batts and I think some small modifications in the dimensions would make it work.

I’m going to start some (parametrized) designs in Fusion 360 on a fork next week, but feel free to start yourself if you want to get going quicker!

@Clayton if the wall units were slightly thinner at 220mm rather than 250mm would this still allow you to build several story constructions? If you used 3/4" 4’ x 8’ sheets of structural plywood, then a wall unit that was 8.75" would fit an R30 Rockwool Comfortbatt perfectly!

@stefan-webb There is structural capacity information for the narrower 200mm wall blocks in the structural engineering guide. Yes, in theory even the SKYLARK200 series should be able to support multiple storeys, but it’s really down to your local structural engineer to assess this for your conditions.

@stefan-webb did you make any progress with the imperial fork? I took a pass today at the Small Wall unit and realized there are probably quite a few decisions with regards to dimensions that have implications for the other building systems. So sharing my first pass and hoping we can compare notes or sync up on a standard approach for the imperial version.

I first made a couple of assumptions about the unit dimensions:

  • For the interior wall “conduit cavity” I made the depth 1.5". I figured this would allow for easy 2x4 blocking if needed for any additional interior support.
  • For the insulation cavity, I made it 9.25". Originally I was still in a dimensional lumber mindset (i.e. 2x10) but then I just saw your note that about 8.75" fitting R30 rockwall batts. I guess the other question is how this impacts the corner units.
  • I went for the 24" on center approach. I considered 16" on center but thought that probably isn’t a material savings over traditional 2x4 or 2x6 construction and the metric ones are close to 24" so it did not seem like a drastic change structurally.
  • I wanted to put the interior “tabs” on a 12" grid so that applying sheet material like drywall would fit with standard building materials.
  • I thought that making the bowties imperial wasn’t worth it given they are a unique shape and already structurally vetted, so adjusted the “tab” spacing to be more regular imperial measurements and then placed the bowties according to the original layout.

Some observations from this first pass:

  • At 24" on center, you can’t fit the interior and exterior wall panels on the same cutting sheet. I made the Small unit 7’ tall, so this also means they will soon be too tall to fit on a single sheet and need to use the splice method.
  • I’m not structurally inclined, so I didn’t feel like moving the spacing of bowties too drastically. It seemed like the bowties were off center in the original units – I assume that’s intentional?

Would appreciate any feedback on the approach and or ideas on how to make the dimensions conform with imperial building conventions.

Thanks!
Wall-S-Imperial.skp (459.2 KB)


Sadly, I didn’t make any progress on an imperial version… I had second thoughts about the WikiHouse concept - see here for some discussion: Wikihouse: Open-Source Houses | Hacker News (ycombinator.com)

There must be a good way to solve construction problems - like speeding up framing - using on-site CNC and engineered sheet goods, just not sure this is the right approach

Thanks for the reply. Sorry to hear you’ve lost interest in the project. I was actively on that thread today hoping I could push HN toward more constructive criticism rather than outright dismissal. I guess I’ll soldier on in the land of inches and feet alone… :slight_smile:

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I used to spend a lot of time on Hacker News when I was a software engineer and seeing that comment section made me realise I wasted 5-6 years believing people on there actually knew what they were talking about lol.

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I found the comment from paulvdh on the HackAday article very ungrounded to outright false in facts. It is a pitty that this comment stays on top and no better arguing feedback comes up the popularity rank.

Plywood is typically made from smaller, lower-grade wood, whereas construction beams require larger, higher-quality, and rarer timber. Its layered structure provides strength in both directions, making plywood versatile for CNC production and automated production, resulting in overall lower waste compared to traditional timber construction.

In my role as lead structure designer for https://www.ecokit.cz/, we developed a fork plywood system tailored for commercial use. Our recent University of Prague break tests revealed that our beams can bear approximately three times more load than initially anticipated.

My country of origin, the Netherlands, serves as an excellent example of mass construction using the WikiHouse system. The Dutch fork WikiHouseNL successfully built a neighborhood of 27 houses with remarkable success.

Wood houses, in general, have lifespans extending to hundreds of years. WikiHouse anticipates a lifespan of 60 years or more with normal maintenance. Moisture, mold and bug control should be in place also for stone houses in general. The unique advantage lies in the system’s adaptability; it can be modified, extended, or partially replaced through the simple reproduction of CNC files stored on a USB stick. This aspect could be a key focus for the HackAday community.

In countries such as the UK, NL, USA, and Australia, WikiHouse construction thrives due to its complete digital design, customization, and rapid production. The advantage lies in well-designed structures arriving pre-produced at the building site, enabling self-builders to assemble them efficiently, thereby reducing construction labor costs. Additionally, viable alternatives for commercial buildings complement the capabilities a company like https://ecokit.us/. With a straightforward construction crew of 2 to 4 and no pre-training, we assemble a mid-sized house on location in a matter of weeks.

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Regarding Metric to Imperial adaptation, I’m a seasoned plywood building system designer with over 4 years of experience.
I can confidently undertake the task of converting and re-nesting the Skylark system in Fusion 360. My expertise includes successfully adapting buildings into Imperial units for several houses.

Furthermore, I am adept at converting architectural drawings into structures that can be assembled using standard or customized WikiHouse parts. And collaborate seamlessly with architects, structural engineers, and WikiHouse directly to ensure optimal outcomes.

I’m organizing a spring trip to Idaho, USA, to oversee the assembly of a house currently in production for the aforementioned company, Ecokit.

Melchior Hof
B.Sc. Technical Engineer
WikiHome S.L.
VAT: ESB02681351
Paraje Fuente Aporta, s/n,
18420 Lanjarón, Granada, Spain
info@cnccasita.com
+34 633630472
www.didihomes.es

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I have used std US materials. Most are actually 23/32nds, those products work fine with the sylark 250 blocks. We used an off the self OSB from a local home improvement store. Calipered thickness and it was 18.4mm…specs for machining say 17.x-18.3. We found tool paths worked fine.