19 November, 2020

Okay, the first thing you should know is that it won’t look like the familiar brick box with a plastic Georgian door stuck on the front, the kind the volume builders tell us we all love so much, but equally it probably won’t come with multiple defects that take an eternity to fix. It may seem like science fiction, but the robot builder is a lot closer than you think. As long ago as a 2018 – ancient history in our fast-moving digital age - the BBC carried a feature about a family moving into the first ever 3D printed house. It took 54 hours to print with another four months to add the windows and roof and was claimed to be 20% cheaper than its traditional equivalent.

Fast forward to this year and it gets interesting. A method developed by Texas A&M University uses soil in 3D printing technology. Finding a successful replacement for concrete would be major step in the global struggle to halt climate change. Using local materials, literally the soil beneath our feet, would also take volumes of vehicles from our roads. The trick is stabilising the soil enough to allow it to be used in this way. According to the University, there is progress but still work to do on this. Even though the printing technology lends itself primarily to making simple forms at present, as a means of delivering low cost housing at volume in underdeveloped parts of the world, it could play a huge part in achieving social and environmental advancement. Experiments have also been made using recycled plastic and bio-waste (or alternatively a bio-derived material like bamboo), but the scale problem is an obvious limitation. Being able to get hold of a reliable source of suitable recycled material to build in volume can’t be guaranteed. 

I’m particularly pleased the see the University involved at the forefront of developing this technology. We have a tie up with Texas A&M and host its student body on its annual visit here, sharing our day to day experiences on everything from UK construction practice to innovation and material science. It’s the students we meet on those visits who will probably end up helping to translate these new ideas for 3D printed buildings into action.

The immediate benefits of the technology are obvious; low labour resource, less waste, more accuracy and above all, speed. The barriers to wider adoption are really about finding better ways to integrate this technology with more traditional building activities that haven’t yet been automated. A revealing parallel comes from our increasing adoption of off-site manufacture for complex building components and assemblies. Taking complicated things off site and making them in factory conditions is reversed by 3D printing which puts the factory process itself on site. Trying to find seamless ‘push fit’ integration is the common theme between both. Frustratingly, despite all the technology available to us it’s still getting stuff to fit properly with other stuff that creates the majority of headaches on building sites.

Where 3D printing can be teamed with parametric design - an algorithm based method of design that organises and distributes material in building components to optimise their structural functions - it creates a powerful tool for designers to move away from simple shapes and express their creativity while the software does much of the hard material science work.

The pathway to a wider adoption of 3D printed buildings has two parallel branches, the first is about the development and scaling of the technology. The second and the most important from the perspective of sustainability is the development of the material the printers will use. There’s an irony in developing a technology that simply allows us to use more concrete than we do now, if it only returns a lower amount of waste from each building we make. This should, however, be distinguished from using 3D printing to make concrete components which can’t be made by any other means. Its unlikely concrete will ever be replaced entirely so ignoring technology that can release its full potential as a building material on ethical grounds seems short sighted. After all, the struggle to halt climate change is a battle being fought on many fronts at the same time.

Like most structural changes in industry the real driver here will be economic. If 3D technology can be developed to a point where it’s capable of producing an equivalent product in its market at scale, and at a significantly lower cost, there is every reason to believe it can grab a meaningful share of the market. But its potential is really much more than that. Its biggest impact could come from allowing us to access a much more sustainable way to build. All eyes on Texas A&M.