Construction labor costs continue to increase and construction productivity has been flat for decades. These forces have created demand for cheaper construction, leading to the application of new tech like machine learning, robotics, 3D-imaging, and drones. While the sector hasn't seen nearly as much attention as fintech or its cousin, proptech, it has received $27 billion in funding since 2008, according to McKinsey partner Jose Luis Blanco. There are two contech unicorns —  Procore and Katerra. We've polled construction tech experts, VCs, and analysts to create a list of 10 of the hottest contech startups to watch in 2020.