Lower Manhattan “has a residual perception as a back-office location,” said M. Myers Mermel, chief executive of TenantWise, a real estate advisory firm, adding that office space downtown leases for around $25 a square foot less than comparable space at Hudson Yards in Midtown, despite having more transportation options. Many prospective tenants still view Midtown as the premier area for office headquarters, he said, while others may have reservations about relocating so close to the site of the attacks. Companies are also eyeing the newly rezoned Midtown East, where a slate of new projects is expected, he said.

The residential market in Lower Manhattan is also changing. “It’s a market in transition, from 9-to-5 to 24/7,” said Jonathan J. Miller, a New York real estate appraiser, referring to pockets of the area that can still feel isolated on nights and weekends.

In the first quarter, the median sales price in the area fell to $1,105,000, a 31 percent drop from the same period in 2017 — the steepest decline of any submarket in the borough, according to a Douglas Elliman report. The decline reflects, in part, a large number of new luxury condo sales that closed last year, pulling this quarter’s numbers down. But that doesn’t account for the entire drop-off, said Mr. Miller, who prepared the data. “I think it’s a reset, just like in the greater market,” he said, referring to the softening of prices at the top of the market.

There are other challenges. Frances Katzen, an agent with Douglas Elliman, said quirks to buying in parts of the area have scared away some clients. In Battery Park City, the land is owned by a public authority that charges developers a payment in lieu of taxes, which can inflate monthly carrying costs. For instance, condos in Battery Park City listed for an average of $1,523 a square foot, practically the same as in Murray Hill, according to Gabby Warshawer with CityRealty, a real estate data website. But the average combined cost of common charges and taxes in Battery Park City was $3,466 a month, about $1,000 more than the Midtown neighborhood.

But new condo developments, like Mr. Silverstein’s 30 Park Place, are in a different class. Located on the cusp of the more affluent downtown neighborhood of TriBeCa, the 157-unit project has just 18 unsold units left (sales began in 2014), with an average price of around $7.2 million, said Rob Vecsler, president of Residential Development at Silverstein.