The construction sector is strategically important to the UK economy, employing 3.1 million people (>9% of the workforce), producing £370 billion in turnover, and exporting more than £8 billion in products and services. However, its current philosophy is resource and cost inefficient and environmentally unsustainable, through its low productivity, slow technology adoption and tendency to demolish and rebuild. Metal 3D printing offers opportunities to solve these challenges and lead to a more productive, innovative and sustainable construction sector. Metal 3D printing technology has transformed other engineering disciplines, including the biomedical and aeronautical sectors, while its application within the construction sector is still in its infancy. The technology has been fundamentally proven through the MX3D Bridge, the first metal 3D printed structure that was opened in July 2021, however there are still a number of barriers preventing more widespread adoption. Current equipment and processes produce elements that have significant material and geometric variability, within the same build and between repeated builds, which is not optimal for real-world use. Furthermore, the limited availability of suitable printing equipment has prevented research into the development of this novel manufacturing technique and its applications to the construction sector. ICWAAM will be a globally unique metal 3D printing facility, dedicated to large-scale, cost-effective applications for the construction sector. It will offer new research capabilities into the printing process, automated manufacture and the repair and upgrade of our critical infrastructure, along with the printing of complex, materially efficient geometries, which are uneconomical or impossible with standard techniques. ICWAAM will fundamentally challenge the current philosophy of the construction industry and lead to its transformation into a more productive, innovative and sustainable sector, with increased worker safety. Without direct access to large-scale metal 3D printing equipment, such as ICWAAM, researchers are unable to undertake this critical research and development, to solve the longstanding challenges in the construction sector.