As you read this, you are likely sitting in a building that will still be standing decades from now. In many ways, that is where the future of buildings begins.

Analysis by the American Council for an Energy-Efficient Economy, based on U.S. Energy Information Administration projections, estimates that 62% of the building floor space that will exist in the U.S. in 2050 was already built by 2022.

When we think about the buildings of tomorrow, we should not only be thinking about what we will build next. We should be thinking about what we can make possible with the buildings already around us.

New construction gives us the chance to apply new thinking from the ground up. Existing buildings give us the chance to build on decades of investment and make those assets more efficient, more adaptable and better prepared for what comes next. And ‘what comes next’ will ask different things of them.

Consider temperature, for example. U.S. Energy Information Administration data shows that commercial buildings in the hottest parts of the country are more than six times as energy-intensive for cooling as those in the coldest regions. Looking ahead, EIA projects that warmer climate conditions will increase cooling demand in U.S. commercial buildings.

The conditions buildings operate in are changing. So are the energy systems around them, the technology inside them, the way people use them and the expectations placed on their performance.

Alongside the question of how we build the next generation of buildings sits another: How do we bring the next generation of performance into the buildings we already have?

Here are four ways I believe building owners and operators can think about that opportunity.

1. See Retrofit as a Pathway, Not a Destination

Buildings have always evolved. Think about how differently a commercial building might be used today compared with 20 or 30 years ago. Occupancy patterns have changed along with the way we work, the technology we use and the demands we place on energy.

The same will be true over the decades ahead. None of us can know exactly what every building will be asked to do in 2040 or 2050. The important thing is that it has the ability to respond.

That is why I see modernization less as a single project and more as a pathway.

In practice, that does not always mean changing everything at once. An owner might improve how a building is operated before major equipment reaches the end of its life, align larger upgrades with planned refurbishment, or make improvements in stages rather than waiting for one major intervention.

The pathway will be different for every building. The principle is simple: understand where you are today, where performance can improve and how each investment can open up more possibilities for the future.

2. Build on the Value Already There

America’s existing buildings represent an enormous investment—in capital, resources and the role they play in our communities. Making them future-ready does not have to mean starting again. It can mean finding new value in what is already there.

For owners, that starts with understanding the building in front of them. Where is energy being used? Where are operating costs rising? Where are occupants experiencing problems? Which systems are approaching a natural point for renewal? And where could an improvement solve more than one problem at the same time?

Those questions can help turn retrofit from a single large decision into a series of more manageable ones.

They can also help reduce disruption. Improvements can often be planned around existing maintenance, refurbishment and replacement cycles, allowing buildings to evolve while continuing to do what they are there to do.

For owners and operators, the opportunity is to make each investment count twice: once for the building they manage today, and again for the building it can become tomorrow.

3. Look at the Whole Value of Better Performance

Energy savings remain an important part of the case for improving buildings, but they are not the whole story. A better-performing building can also support lower operating costs, greater resilience, better experiences for the people inside it and more flexibility as needs and expectations change.

The context around those decisions is changing too. Building Performance Standards are also being adopted in a growing number of U.S. jurisdictions, setting performance targets for existing buildings. For owners, that makes regulation another factor to consider alongside energy costs, resilience, occupant needs, and long-term asset performance.

So where should investment begin? I would start with three questions:

1. Where is the building under the greatest pressure today?
2. Which improvements could create value across more than one area—cost, energy, resilience or occupant experience?
3. Which investments will leave the building with more options in the future?

The answers will be different for an office in Phoenix, a school in Chicago or a hotel in New York. And that is exactly the point—retrofit starts with the building in front of you.

4. Make Adaptability Part of Future-readiness

For years, we have talked about making buildings smarter. That is still important, but the more I look at where buildings are heading, the more I believe adaptability will become one of the defining measures of performance.

A future-ready building does not need to predict everything that will change over the next 20 years. But it needs to be ready to respond when change comes.

For an owner considering the next investment, that creates a useful filter: Will this improve performance today while giving us greater flexibility tomorrow? Does it build on the value we already have? Will it make the next change easier to make?

That last question matters because the best investment may not always be the one that does the most today. It may be the one that solves today’s need while opening up more possibilities for tomorrow. That is what adaptability looks like in practice.

Across America—and the rest of the world—buildings that have already served us for decades will continue supporting our businesses and communities for decades more. We do not need every one of them to become something completely different overnight. However, we do have an opportunity to make them work harder, perform better, and evolve as the world around them changes.

The buildings of tomorrow are already here. Our opportunity is to help them become ready for what comes next.