Energy conservation through efficiency measures is the best way to reduce greenhouse gas emissions in the short term. While energy efficiency upgrades to older buildings are complicated and expensive, new buildings can be constructed according to stronger and more consistent energy efficiency codes. At the same time, we can improve the monitoring and comparison of building energy data to ensure improvements are taking place. Further efficiencies could be achieved with a more intelligent electrical grid, providing opportunities for users to pay variable rates and modify their energy use accordingly.