Wood has always been an essential building material. It is a sustainable material and carbon-negative – meaning it takes CO2 out of the air while growing. People have been building with it for millennia. Only stone carries a richer history as a building material.
A Brief History of Wood as A Building Material
The first recorded use of wood to build houses was in Britain 10,000 years ago. Since then, wood has often been the predominant building material. Even other building materials like stone and brick require the use of wood. In fact, the building of the pyramids in Egypt used up every bit of wood ancient Egyptians could find.
With this heavy use of wood, by the iron age 50% of the world’s woodlands had been cleared. While the forests have somewhat recovered with proper management, that still discourages its use for some people. Sustainability has become one of the top factors during architectural design.
Using All Parts of the Tree
When trees are used for lumber, only the trunk is used. The branches aren’t substantial enough for a traditional building material and are typically chipped or burned. The wood chips can be reused but burned wood obviously cannot. A study published at the 2019 International Conference on Tangible, Embedded, and Embodied Interaction looked at reusing those branches in a new way.
Using an online design interface, the branches are first scanned. Those 3D scans are then analyzed for geometric features. Non-expert users can use the scans of the branches to connect them into an architectural element using an online game called “BranchConnect”.
The geometric features identified by the computer helps the non-expert designer use each branch to it’s full potential. The computer program calculates all the joints and cuts to be made based on the final design. Using this program, a non-technical person can reuse the waste from trees to create interesting architectural elements – all the way from the initial design to fabrication.
Moldable Wood Composites
Researchers are developing methods for creating wood composites that return to their original shape after an environmental disturbance, like a change in temperature. The researchers used a combination of kerfing, a wood-cutting technique, with a shape-memory polymer resin. Kerfing involves cutting the wood widthwise to make the wood bend – kind of like a flexible plastic straw. It is a technique widely used in wood instrument fabrication.
A prototype was developed using a flexible, diamond-shaped kerfing pattern with a temperature-based responsive polymer. This technique could be used to create interesting and inexpensive wood architectural elements that can be transported using compact storage and shaped on-site.
A study funded by the Forest and Wood Products Australia created a composite material, called Microtimber, using a combination of saw dust and recycled acrylonitrile butadiene styrene. The aim of the study was to use a composite for 3D printing that replaces traditional architectural materials. The preliminary testing done during the study shows the material is promising and can provide another avenue to using wood and plastic waste.