The Canton de Vaud revised its Energy law recently and aligned it with the Swiss Energy Strategy 2050. The new law puts an emphasis on energy efficiency and renewable energies and states that 20% of the electricity supply for all new buildings must be from in situ renewable energy sources and 50% of energy consumption of new air conditioning systems must be produced from renewable energy sources. Moreover, large-scale enregy consumers must participate in energy efficiency improvement; and have the obligation to achieve agreed objectives or to perform an energy audit. The audit itself is divided in three main steps: a pre-diagnostic, a diagnostic and an in-depth audit. The audit analyses the potential energy savings, and takes into account both cost and technical feasibility. Finally it suggests a list of actions and priorities in order to improve energy efficiency. The audit program is innovative, and includes tools based on decisional factors which are likely to influence energy-efficiency investment decision in addition to the usual technical-economic audit assessment. Indeed, in a private company, the decision of making an energy-efficiency investment is not based solely on capital cost, other factors, such as the return on investment, investment risk, and the value, e.g. in terms of company’s image impacts, must all be taken into consideration.