Decision model for energy performance improvements in existing buildings

Purpose - The purpose of this paper is to describe a tool that supports an investment strategy aimed at improving the energy performance of existing buildings. It is particularly aimed at large building portfolios, such as encountered on university and corporate campuses, where typically a plethora of potential refurbishment interventions are candidates for a greening effort. Design/methodology/approach - The investment optimization strategy is implemented in a web-based software tool. Under a chosen financial constraint and investment time horizon, the tool empowers campus facility management to make the difficult "greening" decisions as part of their continuous building commissioning. The tool calculates and accepts user data that reflect different types of risks, posed by uncertainties in investment costs, energy performance, and energy cost scenarios. In addition, decision makers (DMs) can set different investment priorities, reflecting their financial risk attitude and commitment to "greenness". Findings - The tool helps DMs determine the best investment options from a set of available energy efficiency improvement options in the light of expected long range energy costs. It will enable the choice of the optimal mix of technologies and buildings within a given budget limit and predict the long-term monetary as well as "green" return on investment. Research limitations/implications - The tool has been tested on a portfolio of campus buildings, but needs further validation with a larger set of buildings in a real life campus management setting. The tool can become a trusted instrument in the hands of portfolio managers faced with the problem to select the optimal mix of technologies, and buildings within the given budget. It should be noted that "investment returns (IRs)" and " commitment to greenness" are just two elements considered in the broader decision making framework of portfolio energy management. Practical implications - The investment tool can provide an essential instrument for campus managers who are faced with the task to refurbish buildings in their portfolio to increase their energy performance. In the current business culture of campus management, the decision to investment in energy savings needs to be weighed against competing initiatives that target greener campuses. The target of the research was to develop an instrument that can help DMs to verify rapidly what can be achieved if a budget line item of, say $10 million would be added to the campus budget for energy performance improvements. Originality/value - The research output from this paper is valuable for continued efforts in the development of indicators that measure "IRs" and " commitment to greenness". Other elements that impact portfolio decision making can be identified in a common decision framework of which the investment tool will become an integral part over time.