By Stephanie Meeks

"Cities need old buildings so badly," the venerable urban activist Jane Jacobs wrote in 1961. "It is probably impossible for vigorous streets and districts to grow without them."

While this maxim was a radical statement in Jacobs' day, at a time when historic blocks and neighborhoods were too often being decimated to make way for ever more highways and "urban renewal," we have since seen the truth of her words. In fact, if anything Jacobs was understating the case.

With the advantages of 21st century technology, unique and nontraditional data sets, and case studies gathered from all across America, we can now empirically prove that historic preservation is one of the strongest tools for urban regeneration we have.

Taken to scale, building reuse can create jobs, amplify economic growth, encourage affordability and sustainability, ameliorate disinvestment and displacement, cut carbon and energy costs, promote healthy lifestyles, and bring Americans together. And the best part is, the buildings that can drive all of these positive changes for your community are already there, just waiting to be revitalized.

The Power of Place

I will delve into National Trust for Historic Preservation's (NTHP) research statistics but first, join me in a thought experiment: What are the places that make your home city or county unique and distinctive? I'm talking about the places that define your neighborhood or town, the places that members of your community think of when they think of home.

Stop and picture one for a moment. What do you see? Was it a park or a church? A local landmark or city hall? Main Street or the old public square?

These sorts of landmarks are the lifeblood of our communities. They help make them feel like someplace rather than anyplace, and in the 21st century, that distinctiveness is a tremendous social, economic, and environmental asset for your community.

As Ed McMahon of the Urban Land Institute well put it, "Place is what makes your hometown different from my hometown. In the Old Economy, markets mattered. In the New Economy, place matters most. In a world where capital is footloose, if you can't differentiate [your community] from any other place, you will have no competitive advantage."

Statistics support McMahon's argument. According to 2006 survey by CEOs for Cities, two-thirds of college-educated young residents say they pick the city they want to live in first, then look for a job.

"Cities are volatile, cities are exciting," one young biotech engineer said of his decision to live in Baltimore. "I feel for a while that cookie cutter was a thing. Now people want a lot more authenticity—in what they wear, in what they eat, in where they live."

That is partly why, according to the New York Times in 2014, the number of college-educated younger people living within three miles of city centers had surged by nearly 40 percent since the turn of the century.

One might argue that local governments hold many amenities beyond just old buildings. And yet, data suggest that the character that older buildings provide is one of a neighborhood's biggest draws. In 2014, the architectural firm Sasaki Associates conducted a 1,000-person survey in six cities—Austin, Texas; Boston, Massachusetts; Chicago, Illinois; New York, New York; San Francisco, California; and Washington, D.C.—to determine exactly what residents loved about their homes.

The answer, they discovered, was historic buildings. Nearly two-thirds (57 percent) of the residents said they liked to stop and admire historic buildings while walking around, far more than those who said the same of modern buildings (19 percent) or skyscrapers (15 percent).

When asked how to best improve the city, the most popular answer by far (54 percent) was working to renovate "existing historic buildings to retain character while making them more useable." By contrast, only 17 percent "felt their city was too quaint and would like to see more skyscrapers and iconic buildings."

These findings mirror those of other studies. A 2007 Gallup poll on happiness and urban living found the strongest positive correlation between happiness and those who felt they lived in a beautiful place. "What makes a building come to be loved?" author Stewart Brand asked in How Buildings Learn.

The answer time and again, he found, was "age. . .the older a building gets, the more we have respect and affection for its evident maturity, for the accumulated human investment it shows." In fact, Brand points out, "Something strange happens when a building ages past a human generation or two. Any building older than 100 years will be considered beautiful, no matter what."

That holds true for tourists as much as for residents. As McMahon pointed out, tourism is a top industry in every state, and the biggest tourist draw is often a historic neighborhood. The French Quarter in New Orleans and Seattle, Washington's Pike Place, for example, are the No. 1 tourist destinations in Louisiana and Washington, respectively.

In Florida, Miami's Art Deco district lags only behind Disney World. Places "that have substantially preserved their past continue to enjoy tourism," argued travel guide writer Arthur Frommer. "Those that haven't, receive no tourism at all. It's a simple as that. Tourism does not go to a city that has lost its soul."

Quantifying the Benefits

For all of these reasons, the critical importance of older places to our communities feels right to us. We all sense how their presence and character positively enhances our lives. At the same time, city planners and representatives rightfully want to make data-driven decisions about the future of their communities.

So in 2014, we at the National Trust began working to empirically quantify these many benefits of older places. After several years of work in dozens of cities across the country, what we have found surprises even us: The power of older buildings is far more than just aesthetic. They are tremendous engines of economic growth, vitality, and quality of life.

For NTHP's initial study, published in 2014 as Older, Smaller, Better, we chose three American cities that boasted both extensive older buildings and strong real estate markets: Washington, D.C.; San Francisco; and Seattle.

Using GIS mapping technology and innovative data sources like business registries, cellphone usage patterns, Walk Scores, and photos uploaded to Flickr, we examined how each block in these cities performed according to 40 different economic, social, cultural, and environmental performance metrics. (For a longer discussion on our methodology, the full report is available online at http://www.oldersmallerbetter.com.)

What we found is that neighborhoods with a mix of older and newer buildings have a "hidden density"—more people and businesses per commercial square foot than areas with just new buildings. They also have more small business jobs, more creative jobs, more new and women- and minority-owned businesses, fewer chain businesses, and more diversity in housing costs, meaning more opportunities for families of all incomes.

These neighborhoods are also more walkable and show more activity on evenings and weekends, with greater cellphone activity and more businesses open late. While the median age of residents is lower than in new-building-only areas, as noted earlier, young people love old buildings. These neighborhoods also exhibit significantly more diversity across age groups.

Enthused by these results, we began applying the same methodology to other places. This past fall, we started rolling out what we are calling the Atlas of ReUrbanism, which applies the Older, Smaller, Better rubric to 50 more cities across the United States (http://www.atlasofreurbanism.com). Once again, what we have found is remarkable.

Across all 50 cities in the Atlas, and when compared to areas with just new buildings, blocks with a mix of old and new buildings have 33 percent more new business jobs and 46 percent more small business jobs. These older areas also have 60 percent more women and minority-owned businesses, and more diverse populations in general—75 percent more Americans of color live in these older areas. They also provide 27 percent more affordable housing units than in new areas.

In every city studied, blocks with older, smaller, mixed-age buildings are denser, both in terms of population and housing units, than all new blocks. This held true for cities of all shapes and sizes, from megacities like Houston, Texas, and Los Angeles, California, to more modest-sized towns. Here are a few examples:

• In Portland, Maine, older, character-rich neighborhoods boast five times the number of women- and minority-owned businesses, three times the population density and number of creative jobs, and nearly three times the number of small business jobs and new business jobs as the newer areas of the town.

• In Pasadena, California, older and smaller areas have 80 percent more population density and 87 percent more jobs in creative industries than newer blocks.

• The older neighborhoods of Winston-Salem, North Carolina, have 56 percent more women- and minority-owned businesses than their newer neighbors.

• For Des Moines, Iowa, these older blocks possess nearly 90 percent more women- and minority-owned businesses.

The list goes on. While our next step is applying the Older, Smaller, Better model to towns smaller than 100,000 residents, we strongly suspect, given four decades of work at our Main Streets America subsidiary, that this case for preservation will hold there as well.

As of 2015, Main Street America has helped more than 2,000 communities preserve and revitalize their traditional downtowns and commercial districts. Over that time, they have seen nearly 530,000 net new jobs generated and more than 120,500 net new businesses opened, while helping to renovate a quarter million historic buildings.

We are extremely excited about what we are discovering. More than just providing useful empirical evidence, this research demonstrates how local governments across America can use their older commercial districts and corridors to generate jobs and dollars, attract more families and businesses, and support urban revitalization.

Smart Preservation Policies at Work

By now, you might be asking: This is all great, but what can local government managers do, exactly, to see these benefits of older buildings work for their communities?

While conducting the Older, Smaller, Better research, we have also been working with the Urban Land Institute on a project called the Partnership for Building Reuse. By talking with local officials, property owners, developers, and community organizations in various cities, including Detroit, Philadelphia, Baltimore, and Los Angeles, to examine specific problems and obtain specific recommendations, we have tried to determine the best policies to put old, vacant, or underused buildings to work. (A comprehensive report on our findings will be available later this year at http://www.partnershipforbuildingreuse.com.)

Speaking in general terms, we discovered two main takeaways from this research. First, building reuse should be the standard, and demolition should always be the option of last resort.

Second, older buildings work best when they are active—filling the needs of today's residents, and serving as centers of 21st century community. We also found that the same issues come up time and again:

Zoning. As Sonia Hirt points out in her book Zoned in the U.S.A., zoning and building regulations in America tend to emphasize single-family, residential-use homes, making it hard to reuse, say, multifamily apartment buildings with a first-floor commercial space.

These cookie-cutter regulations often leave valuable opportunities on the table. In Miami, for example, more than half of the city's densest blocks are in the historic neighborhood of Little Havana, an area that also boasts the highest concentration of affordable rental units.

And yet, Little Havana's unique, low-slung, mixed-use buildings wouldn't pass muster under many of today's more rigid codes. Making these regulations more flexible would greatly facilitate more building reuse.

Parking. By parking expert Richard Willson's reckoning, there are nearly three and a half parking spaces for every car in America. Certain parts of Los Angeles mandate two and a half parking spaces for every residential unit. With younger residents forsaking car ownership at historic rates, do we still need these same parking ratios downtown?

Focusing on empty and increasingly unnecessary parking lots can instead create new opportunities for sensitive infill development that can keep neighborhoods affordable while encouraging healthier forms of transit, such as walking and biking.

Street life. We know that lively streets are vibrant streets that attract more walkers, residents, and tourists. From farmers markets to pop-up exhibitions of street art, we can further unlock the potential of older buildings by helping to facilitate foot traffic in historic neighborhoods. To take one example, Philadelphia introduced a new sidewalk seating ordinance that has resulted in a 73 percent increase in outdoor seating since 2010.

Energy codes. As the saying goes, "the 'greenest' building is the one that's already built." We have found it takes decades for even new, LEED-certified buildings to make up the carbon costs of their construction. Yet many current energy codes act as a barrier to building reuse.

As one way forward, Seattle has pioneered an outcome-based energy code that establishes goals for actual use rather than projected use. This allows developers to take advantage of the many characteristics of historic buildings that make them naturally energy efficient, including thicker walls, deeper eaves, and natural siting.

Investment dollars. One of the biggest obstacles to any reinvestment project, of course, is having the money on hand. That's why the federal historic tax credit, which helps defray the cost of historic rehabilitation, is one of the most powerful preservation policies.

Since 1981, the federal credit has created more than 2.3 million jobs, leveraged $121 billion in private investment, and transformed more than 40,000 unused or underused buildings for new and productive uses. Some 75 percent of the economic benefits of these projects stay in state and local governments, which is why 34 states have created their own state historic tax credits to augment returns.

A study of the Maryland credit, for example, concluded that each $1 invested generates $8.53 in economic activity.

Moving forward, the National Trust stands ready to help communities unlock all the many benefits of their older buildings. The fact is, in places big and small, the best preservation projects are creating opportunities for residents at all income levels, while retaining the local history that ties generations together.

Jane Jacobs was right all those years ago. These places don't just connect us to our past. They are the cornerstone of a brighter future, and we are richer and stronger when they remain.

Stephanie Meeks is president and chief executive officer, National Trust for Historic Preservation, Washington, D.C. (smeeks@savingplaces.org), and author of The Past and Future City: How Historic Preservation Is Reviving America's Communities. On Monday, October 23, she will be the featured speaker at ICMA's 2017 Annual Conference in San Antonio/Bexar County, Texas, that will be held October 22-25.