The top 12 floors of the 20-story office building at 15 West 26th Street are being converted to residential condominium apartments.

The mid-block building, which is known now as 15 Madison Square North, is between Fifth and Madison Avenues and overlooks Madison Square Park and the Flatiron Building.

The very attractive building has a light-beige-colored brick facade with interesting figures on the third and 17th floors and a three-story limestone base. One of the heads of the figures on the third floor is missing.

Limestone escutcheons surrounded by owls are on the fourth floor. The building has a very fine curved cornice.

The building has deeply inset windows at either end of its facade facing the park and the center of the facade are three pairs of windows. The building has consistent one-over-one windows and there are arched windows on the top floor.

The building has a large wood-paneled lobby with concierge desk and a large entrance marquee.

It is being converted by Madison Park Owner LLC, of which Ernest Faraci of Walters & Samuels is a principal and financing for the development has been arranged through Deutsche Bank.

A sales office is expected to open later this month.

The buildings lower eight floors will remain commercial.

The building is the latest of several to be converted in whole or in part around the square. The former Gift Building at 225 Fifth Avenue between 26th and 27th Street is being converted as is the former International Toy Center at 200 Fifth Avenue at 23rd Street and 1107 Fifth Avenue at 24th Street. In addition, the building at 50 Madison Avenue on the northwest corner at 26th Street was recently expanded and converted and plans are underway to convert the great MetLife tower at 1 Madison Avenue into residential condominiums and perhaps a hotel.