Developers like to quote Mark Twain: “Buy land. They’re not making any more.”

A fair point, although Twain probably never said it. Advertisers popularized the slogan in the early 1900s, according to the Center for Mark Twain Studies. Another quibble: There is plenty of land that hardly anyone wants.

In New York, one of the most expensive cities for new development, there are acres of vacant land on irregular lots considered too narrow, too shallow or too onerous to build on. Like the offal left after the prime cuts of meat, they are the odds and ends that take the most skill to manipulate.

But with land prices near all-time highs, developers and nonprofit housing groups are giving the leftovers another look. In some cases, building on odd lots can mean a rare chance to get into high-demand neighborhoods. In others, the lots can represent a relatively inexpensive way to build below-market-rate housing. The city has long grappled with how to deal with vacant public land that comes into its possession — often through unpaid taxes — even as the need for affordable housing has grown.