YONKERS — [What you need to know to start the day: Get New York Today in your inbox.]

Across the suburbs north of New York City, clusters of luxury towers are rising around commuter rail stations, designed to lure young workers seeking easy access to Manhattan. In all, 16,000 apartments and condominiums are in the works in more than a dozen towns, along with spaces for restaurants and shops.

But the boom unfolding in Westchester County is under threat — not from any not-in-my-backyard opposition or a slumping real estate market.

Instead, it is coming from something unexpected: a lack of natural gas.

Con Edison, the region’s main utility, says its existing network of pipelines cannot satisfy an increasing demand for the fuel.

As a result, the utility has taken the extreme step of imposing a moratorium on new gas hookups in a large swath of Westchester, including for residential buildings planned in Yonkers, White Plains and New Rochelle. The only other places in the country with similar restrictions are in Massachusetts, gas industry officials said.