PHILADELPHIA-Construction has begun on the 48-story Residences at the Ritz-Carlton. It is located on a portion of the land which has been vacant since the Meridian Plaza office building was destroyed by fire in 1991.

The developer is a partnership among the locally based Arden Group; Gencom Group, which is based in Miami, and the New York City-based Colgate Development LLC. Colgate is headed by Brian Collins, former partner, COO and CFO of Millennium Partners. Craig Spencer, Arden's president and CEO, says the estimated construction cost is $275 million, making this "the most expensive residential tower ever to be built in Philadelphia."

Plans call for 280 units, but Spencer tells GlobeSt.com he expects some will be combined, which will lower the total count. Selling prices for a 1,000-sf unit begin in the $500,000-range and reach to a high mark for Center City. A 10,000-sf penthouse is priced at $12 million. Completion is scheduled for fall 2008.

Arden, Gencom and Millennium previously partnered in the conversion of the Girard Bank Building into the Ritz-Carlton Hotel. That site is adjacent to the residential condo and will give condo owners access to the hotel's amenities.

Ardmore-based Mariner Commercial Properties owns the remaining portion of the land. At one time, Spencer and Tim Mahoney of Mariner discussed partnering in a single project. Talks fell through, however, and Mariner has also disclosed plans for a condo tower next to the Residences at the Ritz-Carlton.