Two years from completing what he says is the last waterfront residential project in the Seaport, Cronin Development principal Jon Cronin doesn't buy into the chatter that Boston has reached luxury condo saturation.

Residents won’t be able to move into the 114-unit St. Regis Residences, Boston, until 2021, but sales are off to a strong start, Cronin says. As of this week, a third of the units have been reserved in the luxury development going up at 150 Seaport Blvd., and there is a six-week backlog of appointments to visit a new $2M “experience center” down the street at 250 Northern Ave. to give potential buyers a tour of how condos will look and feel.

“It’s amazing considering we just opened the experience center,” Cronin said in an interview Thursday.

The St. Regis Residences, Boston, will be the first urban, all-condo development for the St. Regis brand (an all-condo St. Regis Residences in Rye, New York, is designed for residents aged 55 and older).

But it also comes as Boston’s second Four Seasons opened earlier this year with 160 luxury condos and 146 high-class condos are slated for a Raffles Hotel in Back Bay. Earlier this year, developers pulled the plug on a luxury condo project planned at 1000 Boylston St.

While Boston real estate circles have questioned if there are too many luxury condos slated for the market, Cronin thinks there aren’t enough.

“I wouldn’t be surprised to see [1000 Boylston] rejuvenated at some stage,” he said.

Cronin said there are two types of luxury condo buyers in Boston: those flocking to Back Bay and those heading to the Seaport. He isn’t too concerned with a glut of supply and said the St. Regis is in a good position as the last residential project to go directly on the Seaport waterfront.

The luxury EchelonSeaport condo development is across the street on Seaport Boulevard from the St. Regis.

Cronin said there is a significant level of local interest in the St. Regis, especially from empty nesters looking to downsize and those who bought in the Seaport or a different local luxury high-rise within the last five years.

There has been interest from international buyers, largely from St. Regis’ parent company, Marriott International, marketing to guests at its luxury properties.

“There has been a lot of interest from Chinese and Asian buyers but more for investments, and that’s not something we’re interested in at this stage,” he said.

A potential buyer from the investment community wanted to buy six units, but Cronin said his company turned them down.

Those who do end up with a condo at the St. Regis will be treated to a hefty amenity package, including butler service, two guest suites available to residents and a 12K SF amenity level. The project was originally slated to have 3K SF of amenity space when it was unbranded. When Marriott came on board, Cronin said five planned condos were eliminated to make room for the company’s amenity requirements, including an indoor swimming pool, a library, a spa and a St. Regis Bar.

“It changes the dynamic, but what they bring to the table is more than worth it,” Cronin added.