The faculty and alumni of Indian Institute of Technology (IIT) Madras have developed India's first 3D printing construction technology. Start-up firm Tvasta Manufacturing Solutions and the Civil Engineering Department of IIT Madras have established a unique 3D printing laboratory to formulate technological solutions for construction and take this technology to the mass market. Manu Santhanam, Professor, Department of Civil Engineering, IIT Madras, shares more on the technology. Sustainable construction ‘Green’ or ‘sustainable’ construction means the lower use of resources, coupled with long service life of the structure. As 3D printing optimises the use of concrete only in locations where it is necessary, resource consumption is low. Further, as the concrete is designed with high-performance materials to achieve a unique combination of characteristics, it has good durability and, so, longer service life. Additionally, suitable cement replacement materials are also used in the mix design to achieve printability-related properties. This reduces the carbon footprint of the structures being built.  3D printing can also play a major role in reducing the lifecycle energy costs of a built structure. It can also help build structures that have natural insulation—for example, by having hollow walls or multiple materials within the same wall—thereby reducing the structure’s energy needs during its lifecycle. Concrete architecture 3D printing technology uses precise deposition of raw material (concrete or any other) for building large-scale structures in a layer-by-layer manner. This deposition process and the movement of the 3D printer are all controlled using a centralised controller that receives instructions based on the digital file that has been inputted into it. With this digital technology, there are no limitations based on the skillset of the person involved, which usually constrains conventional construction processes.The technology can be easily used to build complicated architectural elements and structures with curved and organic shapes that are difficult to build using conventional techniques. The development of new technologies in concrete materials, such as ultra high-performance concrete (UHPC), can aid in making the 3D printing of complex architectural shapes easier. The complete lack of requirement of formwork and moulds for building structures can also make it easier to build complex structures with less difficulty. Single-use moulds or formworks are expensive and unsustainable. As 3D printing does not distinguish between the number of structures that need to be built and operates with the concept of mass customisation, building unique architectural structures becomes an easier task. - SERAPHINA D’SOUZA