Historic preservation isn’t the villain in the debate over housing affordability

No matter what folks in Boston tell you, Philadelphia is America’s most historic big city. So why is architectural preservation increasingly under attack here, especially as Philadelphia gets ready for its star turn in the nation’s 250th birthday celebrations?

The movement to protect Philadelphia’s rich and varied architectural heritage was thrown into disarray Feb. 26 when a Court of Common Pleas judge invalidated the historic district created in 2024 to protect Washington Square West, a neighborhood that includes both Colonial-era masterpieces and nationally important infill buildings from the 1960s urban renewal period.

Judge Christopher R. Hall’s decision primarily focused on procedural issues and could be reversed if it’s appealed. Yet it is just one of several existential threats facing the preservation regimen that has guided the city for the last 40 years.

His decision is likely to encourage a group of developers who are challenging the Spruce Hill historic district, which also was created in 2024. It could similarly embolden Councilmember Mark Squilla, a former preservation champion who once created a controversial zoning carve-out to protect a one-story supermarket in Society Hill. Having jumped on the anti-preservation bandwagon, he’s now pushing legislation that many believe would gut the powers of the Historical Commission.

While the issues driving each of these challenges vary, it’s no accident that they’re happening at a time when people are increasingly concerned about rising housing costs. For years, pro-development activists have argued that there is a link between the city’s historic preservation laws and the scarcity of affordable housing. By adding an extra layer of regulation, they contend, those laws restrict where people can build, limit new construction, and raise maintenance costs for homeowners.

There’s no doubt that the city’s preservation laws require owners of historic properties to go through an extra step in the approval process. That takes time and can sometimes add to the cost of a project.

Yet it seems odd that pro-development activists have cast historic preservation as the main villain when so many factors influence the city’s housing supply: zoning regulations, interest rates, availability of labor, cost of construction materials. President Donald Trump’s tariffs alone sent the price of lumber soaring in the last year.

In an effort to put things in perspective, the nonprofit Preservation Alliance recently commissioned an economic analysis to explore its impact on housing prices. The report made two interesting observations: Apartments in older buildings rent for less than those in new ones. And protecting those older buildings actually helps maintain a supply of “naturally occurring affordable housing.”

The study, prepared by the Washington-based Place Economics, also examined claims that historic districts are enclaves for the wealthy and exclude renters. Data show the opposite: Historic districts continue to gain new residents long after they been designated. In fact, between 2010 and 2020, the population of Philadelphia’s historic districts grew almost five times as fast as the city as a whole, which suggests new housing is being built despite the additional oversight.

Not all that construction takes the form of new buildings, however. Even in the best of economic times, erecting a new apartment building in Philadelphia is far more expensive than fixing up an old one. As a result, the city has come to rely on older buildings to provide new housing. Without them, Philadelphia would be a much less affordable place.

In the past, the city’s obsolete offices and factories were the main targets for housing conversion. Those buildings are relatively easy to adapt because they have large, rectangular footprints.

But what about smaller, more irregularly shaped historic buildings? Are the city’s preservation and zoning laws flexible enough to allow more density in old townhouses, which, after all, constitute the bulk of Philadelphia building stock?

To understand the role those buildings can play in the great Yimby-Nimby debates, I reached out to Lea and Evan Litvin, who run Lo Design, an award-winning firm that has its offices in the Rittenhouse-Fitler historic district. Lo Design started out doing single-family homes for developers, but lately they’ve taken on commissions to turn large townhouses into apartments.

Small conversions are more labor-intensive than erecting a new townhouse on an empty site, but they allow the Litvins to do work that aligns with their architectural ideals. The conversions create more housing for less money, using fewer natural resources. “Saving an old building is the most sustainable form of construction,” Evan explained.

Since Philadelphia’s historic townhouses were never meant for multiple tenants, and often have awkward layouts, the Litvins have developed architectural tricks to make them function as apartment buildings. Sometimes that means attaching a new wing on the back. In other cases, they’ve built freestanding structures in backyards.

Their current project at 15th and Waverly used a little of everything to transform a historic Greek Revival mansion into a 32-unit building.

The brick building began its life in 1860 as a private home, complete with a stable. At some point, someone popped on a mansard roof to create a fourth story and added wings on the sides. Then, in the early 20th century, the mansion, stable and a neighboring townhouse were fused into a single building that served as offices for what was then known as the Society to Protect Children from Cruelty.

For the project’s developer, Keith Alliotts, the building’s main attraction was its size — 26,000 square feet, significantly larger than a typical townhouse, which might be 6,000 square feet. He also liked that the location, a few steps from the former University of the Arts’ Hamilton Hall, felt like part of the Rittenhouse Square neighborhood.

Yet the challenges of transforming the awkward amalgamation into a coherent, multifamily residence soon became clear. None of the floors in the different buildings lined up. The U-shaped footprint complicated the flow through the building. The interior was a mashup of Victorian and post-modern details. On top of everything else, the project would need a zoning variance and approval from the Historical Commission.

Getting those permits turned out to be the easy part, the Litvins said. Because the complex had been empty for years and was starting to deteriorate, the neighborhood enthusiastically embraced the idea of using it for apartments.

From the start, the Litvins knew they would have to expand the already sprawling complex to ensure the apartment layouts weren’t too eccentric. Fortunately, there was a large yard behind the house where they could add a new wing to turn the U into an O. They decided to install a large penthouse on top of the stable and insert several connecting passages to improve the interior circulation.

While reusing these buildings was no easy feat, the project is a good example of “gentle density.” The neighborhood gets more rental housing, yet the look of the 19th century mansion remains substantially the same.

By comparison, the first collaboration between the Litvins and Alliotts was a breeze. Alliotts had spent most of his career developing single-family housing in North Jersey before “discovering” Philadelphia during the pandemic. Coming from such a pricey environment, he said, “I was really taken aback by the city’s affordability.” After studying the market here, he fell for an early 20th century brownstone on the 2000 block of West Girard Avenue in Francisville.

Despite the house’s impressive architecture, it wasn’t listed on the city’s historic register. That meant Alliotts could have demolished the building for something new, an approach taken by several other developers on that once-elegant stretch of Girard Avenue.

Alliotts liked the house too much to destroy it. And since the site was unusually deep, he knew he could fit the equivalent of a second house in the yard. But rather than build another stand-alone house, he asked the Litvins to fit a 12-unit condo building in the same space. Alliotts envisioned the condos — now called The Francis — as starter homes, so he wanted to keep the prices below $300,000 for a two-bedroom unit.

Still, 12 units is a lot of density, even for a generous townhouse yard that was 200 by 31 feet. By making a donation to the city’s Housing Trust Fund, Alliotts was able to get a zoning bonus that allowed him to raise the structure’s height to 45 feet, enough for a fourth story.

To avoid jamming the new, metal-clad building against the old brownstone, the Litvins decided to push the condos toward Cambridge Street, which was once a service street lined with carriage houses. That gave the architects space to create a landscaped courtyard between the two buildings.

After the success of the Francis, the Litvins had hoped to replicate the model for a new project at 2313 Green St. in the Spring Garden neighborhood. The main house there had already been divided into five apartments, but the site at 238 feet was even deeper than the Girard Avenue property. They proposed a five-unit stand-alone building in the garden, accessed from alley off Wallace Street.

But this time the Historical Commission and neighbors rejected the proposal.

So, the Litvins reduced the size of the building and turned it into a carriage-house-sized structure with three units. They offset the loss of units by adding a sixth apartment to the main house for a total of nine units.

Some preservation opponents may see the outcome as an example of the nickel-and-diming that occurs when developers attempt to add density to historic properties.

But the fact that a former single-family house will soon accommodate nine apartments reveals the untapped density in Philadelphia’s historic buildings. These conversions prove more housing can be created without sacrificing the city’s heritage.