Odysseas Kontovourkis

3D printing (3DP) is considered as a promising technology in construction industry due to a number of advantages that among others include fast and accurate construction, as well as elimination of formworks and material waste. Although 3DP technology is at an early stage of adoption in construction industry, its positive contribution towards a more sustainable construction approach is well acknowledged. Nevertheless, various constraints prevent its further establishment that include among others lack of knowledge among construction actors, premature investigation regarding techniques and material properties, as well as limited work on design optimization, cost, and environmental impact performance analysis. This chapter aims to contribute towards this direction by analysing the 3DP cost and environmental impact of a number of brick units, forming walls with different geometrical complexity. Results show that while walls’ complexity is increased, there are no significant changes in cost, global warming and primary energy consumption. In contrast, through the application of traditional construction processes, the result values would have been increased proportionally to the degree of complexity. This proves the potential of applying the 3DP technique to the construction of any structure at no extra cost and without increasing the environmental impact. Also, it provides an indication of its potential to be included within a regenerative construction framework.

Regenerative sustainability is gaining great attention as an essential concept for a transformative process, a re-designed mindset shifting from the narrowed focus of considering particular aspects such as energy efficiency, renewable materials, or sustainable technology towards the creation of a self-regenerating social and ecological system. Apart from being a vision of the future, regenerative sustainability has already been implemented successfully in individual projects, plans, and extensive strategies. The goals of this research are (1) to set up the conceptual framework for regenerative sustainability principles in the built environment; (2) to investigate and identify the drivers and barriers faced during the implementation of regenerative principles in the built environment; and (3) to identify gaps in the paradigm shift towards regenerative districts and macro-level projects. A multi-stage methodology was implemented. First, an in-depth literature review was conducted aiming to understand regenerative sustainability state of the art and define the key principles. Then, quantitative data analysis was conducted aiming to identify drivers and barriers of regenerative implementation in buildings following by semi-structured interviews with the representatives of regenerative buildings or districts. The step-by-step methodology resulted in the identified drivers of applying the regenerative principles, which are available financial incentives; marketing and sales benefits; improved companies/investors market image and competitive market advantage; reduced building lifecycle costs/effective use of energy and resources; enhancement buildings’ users’ well-being; and receiving building certification. The main barriers identified were lack of knowledge and experience working with regenerative materials and technologies by employees, consultants, and construction companies and usage of the available tools that enable such constructions; overall stakeholders’ culture and their resistance to changing their mindset toward a regenerative approach; inadequacy of national and international standards and legislation to address regenerative policies; and increased construction cost and time and lack of financial incentives. Ultimately, during the broad examination of the case studies, regenerative qualities served as a valuable insight to understand barriers and drivers at neighborhood and macro levels.

The term Robotic Additive Manufacturing (RAM) describes the process of material deposition in layers, leading to solidified products using industrial robots. Similar processes like construction-scale 3D printing have gained considerable attention during the last few decades and today an increasing interest is observed. Despite their emerging trend, very early adoptions are visible today, with issues under further consideration to include construction time and cost, associated with material minimization and structural efficiency, but also ecological aspect of materials evolved. This paper discusses the current role of 3D printing in the architecture and construction and proposes a framework for implementation using Topology Optimization (TO) principles and clay-based materials. This is applied in a case study example where the design and fabrication of a building element is conducted. The results derived from this investigation are critically discussed and conclusions are drawn for a new and more effective application in the architecture and construction industry.