We revisit optimal investment in energy-efficiency, presenting a decision framework built around the agent's wealth and wealth dynamic. An investment rule in the form of a trigger is derived such that the agent invests the first time the energy-carrier price crosses this threshold from below....

Despite the vast literature on the energy-efficiency gap, there is a general dearth of investment models which incorporate the consumer's temporal freedom in the investment decision. Focusing on the building sector, we formulate optimal investment in energy efficiency as a problem of wealth...