Energy efficiency is the key to reducing fossil fuel use and carbon emissions in the built environment; mitigating fossil fuel consumption in this sector offers a huge, yet-to-be exploited economic opportunity.

These "true stories" that stem from Rocky Mountain Institute's project engagements and other exemplary projects across key building types demonstrate how barriers to deep energy savings can be surmounted using integrative, whole-building design. By recognizing how efficiency gains in one system can affect other building systems and attributes, many small improvements can be combined to create substantially larger benefits.

Browse the case studies to get an inside look at how these real-world deep retrofits markedly improved the economics of energy efficiency, achieving bigger energy savings (and other important benefits) at equal or lower capital cost.