Lightweight Prefab Wood Framing System Goes Together Without Nails

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©. SI Modular via Metza Wood

We do go on about how we love wood construction; it is the only building material that sequesters carbon for the life of the building. These days, “Mass Timber” is all the rage; this is big wood, glue-lam, cross-lam, nail-lam and dowel-lam, using a lot of wood.

But there are other techniques out there that are a lot more efficient in their use of wood, including good old American style platform framing, (which still uses dimension lumber) and the increasing use of engineered wood products in lightweight wood construction. And while everyone is all gaga about 3D printing of houses, I am much more excited about digital fabrication, where computers drive CNC machines to design ever more efficient, lighter buildings out of renewable materials like plywood or engineered wood. We have previously shown the brilliant work of FACIT homes in the UK, but here is another approach.

SI modular building

© SI Modular via Metza WoodThe big Finnish wood company, Metsä Wood, has a wide range of engineered wood products, including Finnjoist I-beams made out of Kerto Laminated Veneer (LVL). They are showing this really interesting SI-modular wood framing system designed by architect Hans-Ludwig Stell from Münster, Germany.

attachment detail

© SI Modular via Metza Wood

With this system, the houses are constructed in timber completely without screws, by simply using interlocking connections in the installation. The starting point for a sustainable concept with the idea of an easy, quick and self-explanatory timber construction was for Hans-Ludwig Stell the Metsä Wood ́s I-beams Finnjoist®.
House on a forklift

© SI Modular via Metza Wood

Hans-Ludwig Stell was given the task of constructing a type of house within the framework of development aid that could be assembled as simple as possible, and almost self-explanatory in various regions of the world. “I was architecturally inspired by steel construction”, remembers Hans-Ludwig Stell, managing partner of the Stellinnovation GmbH, “nevertheless, our company, the architect team, excluded steel construction specifically for this application.”
wood house si modular

© SI Modular via Metza Wood

So they built it out of wood I-beams. The wonder of it is that it needs no nails, thanks to the precision and stability of the engineered wood; the only tool you need is a mallet to knock it all together. Video is in German but really no soundtrack is necessary:

The individual timber components are connected using exact interlocking connections, that join into each other by themselves. Due to the dimensional stability of the I-beams and the precise milling, no assembly errors arise and, in addition, the construction is very stable. Only a hammer is necessary for the assembly. Steel bolts are hammered in selected places. “If you can generally say timber moves - this is not the case here!”, explains Hans-Ludwig Stell to sum it up.
office building

© SI Modular via Metza Wood/ office building

The wonderful thing about engineered wood like this is it’s efficient use of fibre; it doesn’t take much to make the I-beam and it doesn’t take a lot of I-beams to build a house.

This is not only ecological in the use of timber, but also resource-saving due to the optimized design of the I-beams. In addition, not only the volume but also the lesser weight has a positive impact during transport and assembly. In conclusion: The construction kit system with the Finnjoist® I-beams has proven to be an extremely sustainable concept and offers rewards in different construction styles from the traditional residential building up to futuristic seeming office cubes.
proposed development image

© SI-Modular

SI Innovation has come up with the framing system but doesn’t do complete houses or projects, and is looking for partners. It looks like such a neat, fast and efficient system; I suspect they won’t have a lot of trouble. And I also hope this obsession with 3D printing homes out of concrete or plastic will go away; with systems like this, designers are using the latest computer technology to actually think and build in 3D instead of just piling up 2D layers. They are using sustainable, renewable materials as efficiently as can be. This is the future of construction.