Immigrating to the U.S. often necessitates purchasing real estate. The U.S. real estate market is filled with "pre-war buildings" (built before World War II), which are not uncommon and are as noteworthy as new developments. Why is it so difficult to break ground on a new building in a country that invented the elevator and created skyscrapers? Public opinion is one factor; in the U.S., any construction project must first gain the approval of the local community to ensure that the increased foot traffic and traffic pressure from new buildings remain within acceptable limits. Achieving unanimous public approval is no easy task, and negotiations between developers and the public can take months, sometimes even years. The apartment building in Fort Lee, The Modern, was delayed in construction due to strong opposition from the local Southern European immigrant community. However, a more significant reason is that many cities in the U.S. have historic preservation districts, where buildings, regardless of their height or age, must maintain their original appearance and cannot be demolished or altered externally, only internally renovated. Thus, renovation has become the way for people to change their living spaces rather than rebuilding from scratch.
Historic preservation districts are categorized into federal, state, and local levels, so in larger cities, preservation areas may be scattered throughout the city, making it quite challenging to build new structures. For instance, New York City alone has one hundred and ten historic preservation areas plus twenty extension areas, involving over thirty-one thousand buildings, including one thousand three hundred thirty-two designated landmarks, one hundred fifteen interior landmarks, and ten scenic landmarks. Federal preservation areas generally include national parks, national landmarks, and buildings listed on the National Register of Historic Places, while state and local levels include government-built museums and historic districts. Nowadays, there are more and more government and non-profit organizations dedicated to preserving historic buildings; in New York, there are dozens trying to solidify more historic districts in the present and preserve the collective memories of the people.
Even in non-historic preservation areas, building construction cannot be entirely arbitrary. Zoning laws regulate the use of each piece of land, with different areas having varying restrictions on building height, structure, and use. The skyline of Manhattan, Chicago, San Francisco, and other places, with its undulating beauty and diverse architecture, owes much to the role of zoning laws. The height ratio between historic buildings and new structures was calculated from the beginning of urban planning, and the allocation of "air rights" between different areas has already been firmly established, leaving no room for negotiation.
In densely populated metropolitan areas, building height is crucial, and "height limits" are undoubtedly fatal for developers focused on economic benefits. Of course, urban planners are aware of this, so alongside height restrictions, they introduced the concept of "air rights," which refers to the development rights of unused space within height limits. U.S. law allows for the "transfer of air rights": buildings that are designated as landmarks and cannot be rebuilt or raised, if they do not reach the height limit of their area, can sell their unused air rights to adjacent buildings, allowing the latter to gain additional floors.
On one side are developers competing for every inch of usable space, brainstorming new possibilities; on the other side are preservationists holding firm to their beliefs, striving to retain more buildings that embody historical memories. American towns develop in this unique rhythm of competition between both sides.
