Blue–green infrastructure (BGI) has become a practical approach with emerging attention to addressing flood mitigation in many countries worldwide. The environmentally sound, sustainable approach of BGI has led it to gain scientific interest above other available mitigation techniques, such as grey infrastructure, soakaways, etc. This study was intended to conduct a thorough scoping review, followed by a bibliometric analysis, using the VOSViewer version 1.6.19, of the available flood mitigation techniques and the emergence and effectiveness of BGI as a strategy. The scoping review was based on 50+ recent (between 2013 and 2022) journal research papers. The study enabled the development of an elaborative idea about BGI and its applications in Australia, and it describes the trend of research to use BGI for flood mitigation. Following a comprehensive survey, it was established that BGI had been recognized as an effective measure in addressing unexpected floods, and it is indeed a beneficial project in the long term. It mitigates urban flooding, improves the environmental quality by purifying the urban atmosphere, and, further, includes the health and well-being of the community as co-benefits. However, although BGI has many environmental and other connected benefits, there are some restrictions that are decelerating the initiation of BGI as a project. Therefore, this application takes time and effort even before implementation. The bibliometric analysis of this study revealed that robust connectivity is seen in the global perspective between BGI, green infrastructure, and flood risk management, depicting a strong bond. In contrast, in the Australian context, an explicitly networked BGI specifically had yet to be seen, and only “green infrastructure” was used instead. However, the emergence of BGI for flood mitigation was recognized in 2015, while Australian research was likely initiated in 2016. There is less acceleration in Australian studies compared to the global scenario. BGI is a trending topic in scientific research, offering a vast variety of benefits to the country. Concluding, this study strongly suggests an immediate initiation of proper awareness and the development of relatable policies as two primary considerations to encourage the implementation of BGI, which is an effective strategy to address floods in Australia and create livable and healthy cities.

Adaptive Reuse of Historic Buildings (ARHB) is a new concept in developing countries like Sri Lanka. One of the main concerns for the intendancy of decision makers to ARHB is the operational energy. This paper analyzes the research gap of reusing historical buildings as office spaces by utilizing their structural and architectural designs and preserving the buildings’ authenticity for the future. It further aims to protect energy-efficient historical buildings from getting demolished and replaced with new modern buildings. A set of operational energy variables of modern office buildings and the potential historic buildings that can be reused as office spaces was established. During the early 1990s, old Dutch-era buildings in the country were mainly used as government office buildings. Three Dutch-era buildings in Galle Fort and three modern buildings in Colombo City have been selected as the case studies. Design-Builder (DB) software was used to comprehensively analyze sets of operational energy consumption variables. Selected historic buildings in Galle consumed 143.74 kWh/m², 156.34 kWh/m², and 209.39 kWh/m² while modern buildings consumed 337.29 kWh/m², 210.99 kWh/m², and 382.57 kWh/m² as operational energy, respectively. According to the analysis, the operational energy requirement of ARHB is comparatively lesser than that of modern buildings. This study, therefore, mainly concludes that the historical buildings saved more operational energy than the modern building envelopes while considerably reducing environmental impacts and saving the building energy cost.