Building Energy Retrofits: A Review of Decision-Making Models

With increasing energy consumption and the resulting environmental concerns, the need for energy conservation has grown. Buildings, as one of the most energy-intensive sectors, have gained much attention. In 2018, the buildings and construction sector accounted for 39% of the US’s total energy consumption. Therefore, improving building energy efficiency can result in a significant effect on energy conservation. Retrofitting is a practice that can improve the energy performance of existing buildings. One of the main challenges of energy retrofit projects is selecting and prioritizing criteria, systems, and energy-retrofit measures. Numerous decision-making models have been introduced to support retrofit measure selection and combinations for a specific building. However, due to the wide variety of parameters, such as architectural, existing systems, regional, and facility operational features, the decision-making process is a complicated and dynamic problem. This study presents a literature review on energy retrofit decision-making models. We identify the most influential factors, methods used for combining conservation measures, and their implications for lifecycle cost and energy savings. In addition, recommendations for using energy retrofit decision-making models are presented. Results show that although the models’ financial criteria are considered more than social and environmental parameters, factors such as legal regulation and technical considerations should not be neglected to achieve the best possible solution.