Dale, who works in real estate public relations, was interested in a bigger gym. The walk to the PATH train was longer than they wanted, too.

At Trump Bay Street, which opened nearly two years ago with around 450 units, they were impressed by the lobby, which had “beautiful furniture and great design, and it smells lovely,” Dale said. They liked the two-bedroom, two-bathroom units, which had big closets and a big kitchen with an island.

They also checked out the newer and taller Urby, right across the street, which has about 760 units and a cafe in the lobby. “They had a great marketing campaign, and it’s branded very well,” Dale said.

But the bedrooms had built-in cabinets beneath the windows, which the twins felt limited their furniture-arranging options, and the kitchens were comparatively small.

Image The Ellipse, a 380-unit Jersey City rental tower that opened last year, had curved walls that made decorating a challenge. Credit... Robert Wright for The New York Times

They decided to sign on for a $4,700 two-bedroom at Trump Bay Street, which — like other buildings they had seen, including the Ellipse and Urby — had smart elevators that appealed to them. “It groups people together, so it gets you there as efficiently as possible,” Dale said.

From the beginning, though, Dale had been contemplating a one-bedroom of her own. “It was about being mid-30s and still living together,” she said. “As twins, you see other twins as adults in their 40s and 50s and still wearing outfits that match, and we are not going to be that.”