**7. Conclusions**

The evaluation of digital fabrication technologies, particularly 3D printing, has been adopted to enhance environmental performance and economics. This study compared (1) additive manufacturing by means of extrusion method and (2) conventional construction using cast in-situ concrete. The comparative analysis was performed on a single-storey house in the UAE from environmental and economic perspectives. The analysis utilized LCA using midpoint impact methodology ReCiPe 2016 to measure the relative environmental burdens. The LCCA analytical framework was conducted to determine the financial feasibility of the examined scenarios. The results of the LCA and LCCA analyses were combined using a ratio method to determine the system with the higher eco-efficiency. LCA analysis revealed better environmental performance of the 3D printing method due to the absence of several components, such as formworks, steel reinforcement and the lower use of materials, compared to conventional construction alternatives. From an economic perspective, the LCCA indicated that 3D printing is 78% more profitable than its conventional counterpart. The eco-efficiency analysis revealed that 3D printing was the optimum choice. The sensitivity analysis revealed that decreasing cement ratios in 3D printing mortars can significantly decrease the environmental impacts. In this study the 3D printing construction technology showed a better overall eco-efficiency. However, it is acknowledged that the number found in this study may differ for different comparative analysis conditions.

**Author Contributions:** The contribution of each author can be described as follows: Conceptualization, K.P.F., M.A., A.K.T.; Methodology, H.A., M.A.; Software, H.A., M.A.; Visualization, H.A., M.A., A.K.T.; Validation, H.A., K.P.F., M.A., A.K.T.; Writing-Original Draft Preparation, H.A., K.P.F.; Writing—Review & Editing, H.A., K.P.F., M.A., A.K.T.; Supervision, K.P.F., M.A., A.K.T.; Project Administration, K.P.F., M.A. All authors have read and agreed to the published version of the manuscript.

**Funding:** The work in this paper was supported, in part, by the Open Access Program and FRG20-M-E44 gran<sup>t</sup> from the American University of Sharjah. This paper represents the opinions of the authors and does not mean to represent the position or opinions of the American University of Sharjah.

**Conflicts of Interest:** The authors declare no conflict of interest.
