Sustainable Stewardship: Historic Preservation’s Essential Role in Fighting Climate Change

by Richard Moe, President, National Trust for Historic Preservation

As growing numbers of people are worried about climate change, the degradation of the environment, and our relentless consumption of energy and irreplaceable natural resources, it is increasingly apparent that preservation has an essential role to play in any effort to deal with the environmental crisis that looms over us. Because it necessarily involves the conservation of energy and natural resources, historic preservation has always been the greenest of the building arts. Now it’s time to make sure everyone knows it.  

It’s all about sustainability.

Up to now, our approach to life on this planet has been based on the assumption that “there’s plenty more where that came from.” With our environment in crisis, we have to face the fact that there may not be “plenty more” of anything—except trouble. In the face of that realization, we’re challenged to find a way of living that will ensure the longevity and health of our environmental, economic, and social resources.

Much of the debate on this subject usually focuses on the need to reduce auto emissions. But according to the EPA, transportation accounts for just 27% of America’s greenhouse gas emissions, while 48%—almost twice as much—is produced by the construction and operation of buildings. The message is clear: Any solution to climate change must address the need to reduce emissions by being smarter about how we use our buildings and wiser about land use.

I’m not so naïve as to believe that preservation represents the way out of this environmental crisis. But I do believe that historic preservation can be—and must be—a key component of any effort to promote sustainable development. Indeed, preservation is sustainability.

The connection between historic preservation and sustainability is not a new concept. It’s something that many people in the preservation community have believed and talked about for many years. They understand that preservation is “the ultimate recycling.” As long ago as 1980, the National Trust issued a Preservation Week poster that featured an old building in the shape of a gas can—a reminder that reusing an existing building, instead of demolishing it and replacing it with a new one, is one good way to conserve energy.  

The challenge is to help people understand that preservation, by its very nature, is sustainability. The retention and reuse of older buildings is an effective tool for the responsible, sustainable stewardship of our environmental resources—including those that have already been expended. I’m talking about what’s called “embodied energy.”

Here’s the concept in a nutshell: Buildings are vast repositories of energy. It takes energy to manufacture or extract building materials, more energy to transport them to a construction site, still more energy to assemble them into a building. All of that energy is embodied in the finished structure—and if the structure is demolished and landfilled, the energy locked up in it is totally wasted. What’s more, the process of demolition itself uses more energy—and, of course, the construction of a new building in its place uses more yet.

It all comes down to this simple fact: We can’t build our way out of the global warming crisis. We have to conserve our way out. That means we have to make better, wiser use of what we’ve already built.

Still, too many people don’t yet understand that preservation must be an integral part of any effort to encourage environmental responsibility and sustainable development. Most recent efforts by the green community place heavy emphasis on new technologies rather than on tried-and-true preservation practices that focus on reusing existing buildings to reduce the environmental impacts associated with demolition and new construction.

This emphasis on new construction is completely wrong-headed. Here’s what we have to keep in mind: No matter how much green technology is employed in its design and construction, any new building represents a new impact on the environment. The bottom line is that the greenest building is one that already exists.

It’s often alleged that historic buildings are energy hogs—but in fact, data from the U.S. Energy Information Agency suggests that buildings constructed before 1920 are actually more energy-efficient than buildings built at any time afterwards—except for those built after 2000. It’s not hard to figure out why. Many historic buildings have thick, solid walls, resulting in greater thermal mass and reducing the amount of energy needed for heating and cooling. Buildings designed before the widespread use of electricity feature transoms, high ceilings, and large windows for natural light and ventilation, as well as shaded porches and other features to reduce solar gain. Architects and builders paid close attention to siting and landscaping as tools for maximizing sun exposure during the winter months and minimizing it during warmer months.

Unlike their more recent counterparts that celebrate the concept of planned obsolescence, most historic and many other older buildings were built to last. Their durability gives them almost unlimited “renewability”—a fact that underscores the folly of wasting them instead of recognizing them as valuable, sustainable assets.

I’m not suggesting that all historic buildings are perfect models of efficient energy use—but, contrary to what many people believe, older buildings can “go green.” The marketplace now offers a wide range of products that can help make older buildings even more energy-efficient without compromising the historic character that makes them unique and appealing. And there’s a large and growing number of rehab/reuse projects that offer good models of sustainable design and construction.

More recent buildings—especially those constructed between the 1950s and 1980s—pose a greater challenge. Many of them were constructed at a time when fossil fuels were plentiful and inexpensive, so there was little regard for energy efficiency.

Today, these buildings make up more than half of our nonresidential building stock. Because of their sheer numbers, demolishing and replacing them isn’t a viable option. We must find ways to rehabilitate these buildings and lighten their environmental footprint while still protecting their architectural significance. This is a challenge that preservationists and green-building advocates must face together in the coming years.

I believe that climate change is the defining issue of our time. What’s at stake is nothing less than life as we know it on this planet. The fact that the threat is not immediate does not mean that it’s not urgent. The experts tell us we have no time to lose. The debate is over, the facts are in, and it’s time to act.

One of the first and most important things that must happen is a thoroughgoing revision of current government policies that foster unsustainable development.

For decades, national, state and local policies have facilitated—even encouraged—the development of new suburbs while leaving existing communities behind. As a result, an ongoing epidemic of sprawl ravages the countryside, devouring open space, consuming resources and demanding new infrastructure. Meanwhile, in the cities, disinvestment has left viable housing stock abandoned and schools slated for closing in areas where infrastructure is already in place, already paid for.

It makes no sense for us to recycle newsprint and bottles and aluminum cans while we’re throwing away entire buildings, or even entire neighborhoods. This pattern of development is fiscally irresponsible, environmentally disastrous, and ultimately unsustainable. To replace it, we need federal policy that directs growth to existing communities.

We also need incentives to encourage reuse and energy upgrades in older buildings. Over the past ten years alone, historic tax-credit incentives have sparked the rehab of more than 217 million square feet of commercial and residential space. We must insure the continued availability of these tax credits, and expand their use in older buildings that are not necessarily historic but still re-usable. Equally important, we must provide similar incentives that will help private homeowners use green technology in maintaining and renovating their homes.

Finally, we need to improve green-building rating systems to ensure that they recognize the importance of building reuse. Under the current Leadership in Energy and Environmental Design (LEED) standards developed by the U. S. Green Building Council, for example, a new building can be certified “green” even if it’s constructed outside densely populated areas; this kind of development amounts to “green sprawl,” which is contrary to every principle of sustainability. Also, under the current LEED rating system, reusing 75% of an existing building core and shell is assigned the same value as merely using environmentally-friendly carpet.

The National Trust and others are working with the U.S. Green Building Council—at their invitation—to improve these and other points. It will take time, but I hope that we’ll eventually arrive at a revised LEED rating system that accurately reflects the environmental benefits of “smart” locations and building reuse.

These public-policy steps are critically important, but we shouldn’t wait for government to act. That’s why the National Trust has launched its own Sustainability Initiative, which will gather reliable data on the comparative energy costs of rehab vs. building new. We’ll also undertake a major outreach effort to inform everyone—especially architects, developers, property owners and policy makers—about the benefits of preserving and reusing older buildings. And we’ll make our website a “best practices” resource for how to reduce energy consumption and use green technology in the rehab of older structures. 

Over the years, as the focus of our work has evolved, we’ve demonstrated that preservation is good for the pocketbook as well as the soul. Now, in the face of unprecedented climate change, we’re prepared to demonstrate that preservation is an essential tool for sustaining the environmental viability of the planet as well as the quality of life for ourselves and our children.

This article was excerpted from a speech made at the National Building Museum in Washington, D.C., on December 13, 2007, when Moe received the museum’s Vincent Scully Prize. It is reprinted here with the kind permission of the National Trust for Historic Preservation. The full text can be found at www.preservationnation.org/about-us/press-room/speeches/sustainable-stewardship-scully.html.