These additions are drastically altering the skyline. Manhattan is experiencing an unparalleled increase of towering structures. In the past, new buildings would be shorter and less tall, but over time they're being raised higher and higher. The city's building regulations require that all buildings over 10 stories high be approved by a special panel called the Landmarks Commission. They can refuse to approve any proposal they feel might alter the character of a neighborhood or ruin views from nearby properties. But these restrictions only apply to new construction. Older buildings can be changed much more freely. There are many examples of this in Manhattan alone-from ancient skyscrapers like Rockefeller Center to modern marvels like Trump Tower. If you own part of any of these buildings, you can change what goes on inside them as long as you follow certain guidelines. For example, your landlord can't just add four stories to their apartment house without getting permission from the Landmarks Commission. But they can replace one floor of apartments with a single large room if they want to. Or they could remove every other floor in each unit if they wanted to make more space available. In general, old buildings are far more flexible than new ones.