The feasibility of installing rainwater harvesting systems in buildings is usually defined based primarily on economic analysis. In this perspective, we reviewed the literature related to water consumption in buildings, rainwater use, and environmental assessment tools to evaluate the impact of rainwater harvesting on the environment. Identifying water end uses in buildings showed a high potential for potable water savings through alternative sources (e.g., rainwater use for non-potable purposes). Most studies reviewed found potential for potable water savings from 20 to 65%. Moreover, the literature reported that rainwater harvesting systems might reduce the runoff volume from 13 to 91%. However, other possible benefits and impacts of the systems on water flow and the environment must be assessed in addition to the potential for rainwater harvesting. Life cycle assessment, life cycle cost assessment, and water balance modelling have been used in urban water management. Most life cycle studies reported that rainwater harvesting systems have better environmental performance than centralised systems. The water balance method may effectively determine the impacts these systems cause on the water cycle. Using life cycle assessment and the water balance method together is essential to evaluating rainwater harvesting systems integrated into the urban environment.

This review aimed to critically assess the effectiveness of LEED certification in enhancing the energy performance of buildings. This study discusses the background to the creation of LEED, the LEED energy performance assessment, the consumption of certified buildings compared to non-certified buildings, the consumption predicted by simulations versus actual consumption, and the influence of considering thermal insulation in the envelope on the effectiveness of the certification. The review highlights that LEED was developed in the United States and bases its energy performance assessment on ASHRAE 90.1. Findings highlight significant energy performance variability among LEED-certified buildings due to factors like geographic location, building type, and discrepancies between predicted and actual energy consumption, often influenced by occupancy patterns and user behaviour. While higher certification levels generally correlate with better energy performance, lower levels frequently underperform. Additionally, in hot climates, thermal insulation strategies following ASHRAE guidelines may inadvertently increase cooling demands in buildings with high internal loads, hindering heat dissipation. In conclusion, although LEED represents a significant milestone in advancing sustainable construction practices, its energy performance framework requires refinement to better account for diverse climatic and cultural contexts, thereby optimising its contribution to energy efficiency.