For Alquist Founder and CEO Zack Mannheimer it all started while working for a consulting firm helping cities with economic and workforce development. A key part of that was the attraction and retention of workers, and the number one problem there was housing - his firm could solve other problems for its clients, but not that one.
Then several years ago he heard about 3D printing, became obsessed with the idea, and working with Virginia Tech University, printed his first home a year ago.
"The way it works is you lay a foundation traditionally. The printer which is a very large robot - there are two styles, there's a robot arm printer and there's a gantry printer - we've been using the gantry although we're moving to a robot shortly. The printer gets set up on the foundation, we mix all of our material on site, so the raw concrete mix which is a reinforced concrete gets delivered to the site, we pour that through a silo into our pump and the pump system mixes it with water, then the material is pumped through a hose directly to the print head, and it lays out layer after layer of material until you have your wall sytem."
The printer nozzle lays out two walls, with a gap in between for electrical and plumbing, and for insulation.
"There really is no limitation except for imagination. We've only printed one story so far. We've gone as big as 1,600 square foot but you can go as big and tall and you like. There are printers on the market that are capable of going up four stories and new ones come online all the time. That being said, there's only three instances of anyone printing above one story so far in the world. We do plan on printing more than one story later this year but technically there's no limitation it's just adapting to the technology."
Since building houses using 3D printers is still very much in the experimental phase, the cost savings are minimal so far.
"Three D printing methods allow several cost savings. So first of all you can print faster than you can put a traditional framed wall system. We can print the exterior walls of a home in anywhere between 18 and 25 hours depending on size and location. Secondly you have a labor savings. We technicaly only need two humans to operate the printer - today we use three or four and as the teams get more experienced that will decrease. And the material itself costs less than lumber"
But by 2025, Mannheimer says savings could be 30 per cent versus the cost of building a traditional home.
"There's lots to learn still.There's no perfect printer on the market and there's no perfect material. Of course concrete is great but it's far from the greenest material on the market - we know that and we want to get away from that. We're going to be experimenting this year with new materials with recycled products in it with hemp in it with other renewables and trying to make the material stronger, greener, and less expensive - that is an on going pursuit. But there's still a lot to learn, the pump systems to get stronger, the machines need to get faster, and the workforce needs to get bettet trained."
Alquist 3D will build its first homes in Iowa this year, with four in Muscatine this spring and six more in the fall. Then it'll build some more in western Iowa, in Lennox and Malvern. And he's talking with other communities about future projects.
Classes on 3D printing using concrete will begin in the fall at Muscatine Community College. You can watch a video of 3d home printing on the Alquist 3D website.
