Seven-time Emmy-winning television writer and producer David Chase has two adjacent but not combined penthouse apartments atop one of the four towers that anchor the London Terrace complex in New York City’s prime West Chelsea neighborhood available at $16.5 million.

The larger of the two penthouses, the home of celebrated author and activist Susan Sontag until her death in 2004, comes in at about 2,700 square feet, and was purchased by Chase, creator of “The Sopranos,” in early 2013 for $9.6 million. Chevron-patterned wood floors run throughout the white-walled aerie that contains a sun-soaked, triple-exposure living room with a fireplace, and a sleekly outfitted all-white eat-in kitchen with a walk-in pantry and a second fireplace. There are two ample en suite guest bedrooms, one with yet another fireplace, plus a privately positioned master suite with six closets, a library nook, and a marble-floored bathroom.

The smaller, second penthouse was acquired in August 2014 for $4.6 million, and current listing details show that it’s configured with two bedrooms and two bathrooms, an eat-in kitchen, and a corner living room with a fireplace.

Marketing materials state that the penthouses have “fully approved” plans for a “masterfully designed” unification that would bring the combined size to around 5,000 square feet with at least three bedrooms, 4.5 bathrooms, and approximately 2,200 square feet of private terraces. Alec Baldwin, about to have a third child with his wife, Hilaria, will soon be in need of a bit more space than their Greenwich Village duplex provides, and has reportedly peeped the penthouses at least three times. London Terrace, a colossal assemblage of rental and condominium buildings, has a long list of high-profile past and present residents such as Debbie Harry, Nicole Kidman, Katherine Helmond, Tim Gunn, Sam Waterston, and Lorraine Bracco.

listing photos and floor plans: Compass