Building-integrated photovoltaic (BIPV) systems coupled with energy storage systems offer promising solutions to reduce the dependency of buildings on non-renewable energy sources and provide the building sector with environmental benefits by reducing the buildings’ environmental footprint. Hence, the economic viability of such energy systems must be further assessed, particularly regarding the market price and required initial investments. This paper aims to evaluate the net present cost (NPC) and saving-to-investment ratio (SIR) of the electrical storage system coupled with BIPV in smart residential buildings with a focus on optimum sizing of the battery systems under varying market price scenarios. Therefore, a parametric energy model of a residential building, a life cycle cost analysis approach, and a Monte Carlo analysis are carried out to elaborate the dynamism between the storage size, market price, and net present cost of the system over its life cycle. The results provide a decision-support tool to find the cost-optimum size of the battery systems and to realize the interplay between the battery system size, the market price, and the economic feasibility of the electrical storage system coupled with residential BIPV. In more detail, the results reveal that the economic viability thresholds of the battery systems’ market price are in the range of 250–300 €/kWh depending on the chosen life cycle cost indicators, while the cost-optimum size of the battery systems varies noticeably according to the market price of battery systems. Furthermore, the paper provides insight to designers, policymakers, manufacturers, and the market for developing scenarios to accelerate the implementation of energy storage systems in the building sector.

The application of sustainability assessment in a decision context is associated with various challenges that explain why the transition to action-oriented knowledge still needs to be fulfilled. Therefore, this paper aims to explore the associated challenges in sustainability assessment in the decision context of the built environment. Several publications are reviewed to provide a systemic understanding of the associated complexities. The challenges in sustainability assessment in the built environment are categorized at different levels, from understanding to measurement and implementation. The challenges are further categorized into definition, context, interpretation, data, measurement methods, uncertainties, indicators and indices, results, coordination, conflicts, and action-oriented knowledge. Moreover, according to the nature of each challenge, they are classified into epistemological, methodological, and procedural challenges. The novelty of this review is that it reviews and reports almost all fragmentedly reported challenges in sustainability assessment of the built environment in the literature within a holistic framework that provides a clear understanding of the state of the art and second discusses them within an integrated framework (the Sustainability Assessment Network) including the position of active-role players to resolve them, including strategists, scientist, and stakeholders.