New condo developments on City Island, which hugs the eastern edge of the Bronx, aren’t proposed often, and residents of this 230-acre island have a history of being tough to please.

But On the Sound, a 43-unit condo development proposed for City Island’s “Gold Coast” on Long Island Sound, seems to have passed muster. The project will be the first large-scale residential development in about 15 years for City Island, a place that is reminiscent of a fishing village in New England and as such an anomaly within the borders of New York City.

With construction already underway and sales starting this fall, the development should see its first buyers moving in by fall 2015, said Thomas P. Ryan, a senior vice president of Greystone, the property development company building the gated complex. The project will consist of 21 two-family dwellings, as well as one single-family home and a clubhouse, clustered on five waterfront acres at 226 Fordham Place. Almost every unit will have water views.

“Without doing any marketing whatsoever, just by putting up a construction fence and putting excavators out there, we’ve had a lot of interest,” he said. “There seems to be high demand for what we’re doing.”