WASHINGTON — Tall cranes dot the sky along 14th Street N.W., hovering above half-finished high rises that are replacing vacant lots and low-slung buildings.

In the next 24 months, virtually every block in a one-mile stretch of 14th is slated to gain a new or renovated building containing residential units and ground-floor retail space. When the dust clears, the strip will have more than 1,200 additional housing units and more than 85,000 square feet of additional retail space.

Few here are surprised. After all, the section of 14th Street from Rhode Island to Florida Avenues, about two miles north of the National Mall and near a major Metro station, has been undergoing redevelopment for years. But in 2008 financing for new projects stopped, and it did not start flowing again until 2010. Now the taps are fully open.

A few small condominium projects are in the mix, including PN Hoffman’s transformation of a Verizon building into 34 upscale units. But given Washington’s very tight rental housing market, developers’ main focus is on apartment buildings, most of them skewing toward the high end.