For decades now, energy efficiency has been a stalwart tool for cutting greenhouse gas emissions and lowering utility bills. With appliance standards, utility programs, building codes, and other energy-saving measures, we’ve established a resource that now powers over a third of the U.S. economy.

But we need to fundamentally transform our strategies to accelerate this progress if the world is to avoid the worst impacts of climate change. Limiting global warming will require “rapid, far-reaching, unprecedented changes in all aspects of society,” the Intergovernmental Panel on Climate Change warns. In other words, the status quo isn’t going to cut it. Beyond energy efficiency, we need to be driving straight at the heart of buildings-driven climate change by focusing on emissions impacts and marrying climate with equity interests to make the results durable.

We think we can do this through a new conceptual framework: energy optimization. Energy optimization means using—and not using—energy in the built environment to maximize benefits for the climate and for people. From a resource perspective, we’re talking about a three-legged stool:

• Energy Efficiency: Expanding energy savings primarily in existing buildings
• Demand Response: Helping customers to use energy in concert with a dynamic power grid
• Fuel Switching: Stop burning fossil fuels indoors and switching to electricity

Forty percent of the nation’s carbon emissions are wrapped up in our buildings. These three energy interventions will enable our building sector to scale up performance to match a power sector driven by clean energy. But we can’t just rely on renewable energy to absolve us of the need to reduce, shift, and electrify—that is, optimize—energy use in buildings. We’re making long-term investments here: structures that can last a century and heating and cooling systems that can last two decades or longer. Because power plants turn over far faster than buildings, we need to be making changes before the power sector decarbonizes.

To move toward a new era of energy optimization, we propose five key changes to the existing efficiency approach:

1. Electrify the built environment efficiently and rapidly. Thanks to Herculean work of many, the widespread switch to efficient lighting is under way—now we must turn to efficient electric heat as the nation’s leading efficiency measure to achieve higher levels of savings.
2.  Expand finance to jumpstart the retrofit market. The bulk of optimizing energy use in homes and businesses between now and 2030 will be heating and cooling existing buildings better while using less total energy.
3. Empower customers with advanced technologies. Before customers can decide to save energy, they need to have their energy data presented to them. Smart meters, intelligent management systems, and other tools can help point to opportunities.
4. Shift to meter-based savings. Long-established advances and cost declines in meter-based measurement technologies are ready to help revolutionize how we quantify energy efficiency and move away from the current processes that slow us down.
5. Modernize codes and standards. We need modernized building energy performance standards that not only address new construction but also jumpstart the retrofit market.

All of these changes will help further our climate goals, but they are also good news for people: People who can install efficient heat pumps, people who will pay lower total energy bills, people who will breathe fewer toxic fumes from their gas stoves, and all the construction workers we’ll need to employ to make it happen.

In the coming weeks, we’ll be rolling out a series of posts outlining each of these strategy pivots in more detail, as well as a perspective on an important new report out of California, “Equitable Building Electrification: A Framework for Powering Resilient Communities.” The challenges they entail are complex and daunting—but thankfully, our energy efficiency community has proven its ability to accomplish the daring, to beat the forecasts, and to deny the skeptics. That tenacity, coupled with a broader coalition going forward, is a winning recipe for progress.