The ultimate test of the business case for high performance low carbon building is to consider how the human benefits of these buildings could be reliably quantified to prove beyond all doubt the positive Return on Investment (ROI). After all, staff costs, including salaries and benefits, typically account for about 90% of business operating costs.

Energy saving is a major policy objective worldwide and in the EU in particular. Evaluating the convenience of energy-efficient investments, however, is complex. This paper aims to apply stochastic Life Cycle Costing to assess the economic value of energy-efficient building retrofitting investments. The proposed approach investigates how macroeconomic variables affect such an evaluation by explicitly taking into account their interdependent stochastic nature.