I don’t think it’s a secret that we here at Market Urbanism are skeptical of mandatory historical preservation of private property, but until recently I hadn’t realized how utterly counterproductive some of these efforts really are. I’m talking specifically about cases where historical preservation statutes forbid additions from being added to the tops of buildings – structures that increase a building’s value and floor space without detracting much from the history, facade, or even interior of the building.

New York City, with its rapacious developers and entrenched preservationists, seems to be a hotbed of addition-induced turmoil. The enormous pent-up demand occasionally surges through the legal barriers, with unapproved additions and penthouses popping up throughout the city, and developers sometimes being forced to tear them down. A relatively innocuous penthouse on top of a hotel in TriBeCa that’s partly owned by Robert De Niro narrowly avoided this fate a few days ago, but a one-story addition atop a townhouse in Chelsea wasn’t so lucky – apparently slaves used the rooftop to flee when it was a part of the Underground Railroad, so the addition is being taken down and the roof is being restored in all its slave-fleeing glory. A few months ago a building in Dumbo lost six stories that were almost five years old because the owners never got a zoning variance to add residential space to the commercially-zoned property. Developers like Ramy Issac and Ben Shaoul have become infamous as “tenement toppers,” and while their tactics are sometimes unsavory and illegal, the fact that anyone is willing to take such a risk is indicative of the extraordinary unmet demand for density in the city.

And with the city’s real estate market already heating back up, this demand is only going to become stronger. Even if the preservationists win today’s battle and stave off redevelopment for a few more decades, densification will need to occur some day. And when it does happen, these small buildings are going to be the first to go. While just a few extra stories would raise their value and protect them against future redevelopment through the price mechanism, these short properties with only a few tenants will only become more attractive targets for developers. And unlike today, when developers want to work with the existing structure and add on to it in an incremental fashion, the redevelopment of the future will likely involve razing the building entirely.

Beijing is currently facing such a dilemma with its traditional hutong neighborhoods, albeit one caused by decades of redevelopment-strangling Maoism rather than the redevelopment-strangling Greenwich Village Society for Historic Preservation. Robbed of the opportunity to densify gradually over the course of the 20th century, the only practical option now is total demolition. The alternative – museumification – is not practical in a rapidly-urbanizing China, and I don’t think that New York is quite ready to accept its fate as a New World Venice either.

So while historical preservation may have its place, it is very shortsighted to use it against developers who want to retain the facade and vast majority of the original structure of a pre-war building. If preservationists in the East Village and Dumbo, for example, succeed in blocking these eminently reasonable proposed additions, they’ll have only themselves to blame when, fifty or a hundred years hence, the buildings are torn down completely because developers see no value in their small size and low revenues. Additions add value to buildings, and this market value is the best way to ensure preservation in a profit-driven society. In its dogmatic opposition to even non-destructive redevelopment, this form of total preservationism is sowing the seeds of its own destruction.