The research field of construction robotics broadens further and further in terms of complexity, approaches, technologies used, active stakeholders, and application areas. Worldwide labour and resource shortages, the need to increase circularity and resource efficiency, new materials and the increasing utilisation of digital construction tools in the planning and construction industry massively spur the uptake of robotic solutions for on-site construction. More and more BIM2Robot pipelines, human factors engineering, construction materials and sustainability become key aspects in construction robot design.

The construction industry, together with the materials industries which support it, is one of the major global exploiters of natural resources, both physical and biological. Whilst the need of public housing due to the population explosion is continuously increasing (United Nations, 2019), the material and labour costs are rising. The increased competition and shrinking profit margins are some further challenges facing the construction industry. According to McKinsey Global Institute, the construction industry has an intractable productivity problem. Global labour-productivity growth in construction has averaged only 1 percent a year over the past two decades, compared with growth of 2.8 percent for the total world economy and 3.6 percent in manufacturing (McKinsey Global Institute, 2017). Therefore, using innovative solutions to increase the productivity of the construction sector becomes critical to the sustainability of the construction industry.

Recently the worldwide growing need and interest in construction robotics became highly evident. A multitude of robot systems are pushed by start-ups and spin-offs and their investors to the market. This is backed by an enormous number of activities and projects carried out in the academic area pushing to the boundaries of what is technologically possible.

Major associations and their conferences increase significantly in popularity such as ISARC (International Association for Automation and Robotics in Construction), EC3 (European Council of Computing in Construction), Robots in Architecture, and the CyberCraft Kolleg. Competency in digital construction, automation and robotics becomes a key for all stakeholders in the construction industry and many universities worldwide launch dedicated interdisciplinary programs. Major funding programs such as Horizon Europe (Europe) massively request and fund the development of robotic solutions for construction such as drones, mobile robots, 3D-printing solutions, cable-driven robots, and exoskeletons.

Regulators and standardisation organisation start to develop the first certification and standardisation schemes for construction robots and large software companies make attempts to allow to simulate and program robotic construction processes efficiently and robustly based on digital building and construction data.

To showcase the diversity of cutting-edge research in the area, this special issue invited seven extended versions of selected papers from the ISARC 2021 conference. As such, this issue covers the automation of construction process by parallel-kinematic manipulators, comparison of on-site and off-site robot solutions, automated and robotic laying activity with heavy pre-fabricated elements, and progress estimation for automated construction machines. Furthermore, novel approaches to teaching construction approaches are addressed, passive back-support exoskeleton in material handling tasks are discussed, and cobot uptake in construction is analysed.