A topping-out ceremony of the 19-story residential condominium building under construction at 170 East End Avenue was held this morning on the building's 12th floor.

Orin Wilf, shown at the right, a principal of Skyline Developers, LLC, the project's developer, said that about 50 percent of the building's 110 apartments have already been sold. The building is scheduled for completion next Spring.

Mr. Wilf told CityRealty.com that the high-end of the market has "really taken off" over the past two or three months and that he expects the project to be sold out by the time it is ready for occupancy.

The building occupies the blockfront on East End Avenue between 87th and 88th Streets directly to the north of the low-rise buildings on Henderson Place. The site, which is a stone throw away from Gracie Mansion in Carl Schurz Park, was formerly occupied by the Beth Israel Medical Center Singer Division.

The building's design by Peter Marino has a very high fenestration ratio and a Mondianesque-grid patterning that incorporates thin dark balconies with glass railings, deeply inset, multi-paned windows, and limestone-colored pre-cast concrete facades. The two-story base of the building will be rusticated limestone. Different sections of the building have their own pier arrangements and the center of the building is clear glass, which visually attempts to divide the mass of the building into two towers. Low-rise wings extend from the tower on the avenue along the side-streets framing a large communal garden.

Apartments will range in size from 1- to 5-bedroom apartments.

A five-bedroom, eight-and-a-half bath unit with 6,336 square feet is priced at about $14,400,000. A five-bedroom, six-and-a-half bath apartment with 4,924 square feet is priced at about $15 million. A four-bedroom, 5 bath unit with 3,916 square feet is priced at about $7,500,000. A two-bedroom, two-and-a-half bath unit with 1,500 square feet is priced at about $2,595,000. A one-bedroom with one-and-a-half baths and 1,008 square feet is priced at $1,015,000.

The building will have a large rear garden with a large waterfall that will be visible form the building's entrance on East End Avenue.

Mr. Wilf's organization's business activities are known as Garden Homes and Garden Commercial Properties. In 1955, Harry and Joseph Wilf established Garden Homes to erect single-family houses in New Jersey and subsequently expanded to also develop condominium apartments, office buildings, shopping malls and hotels in the New York metropolitan region as well as in California, Maryland, Florida, Pennsylvania and Delaware, Arizona and Israel.

Garden Homes Development is based in Short Hills, New Jersey and has operations in 37 states.

Its other activities in New York City include condominium apartment conversions of properties at 280 Park South and 75 West Street. It is also converting 41 Broad Street for the Claremont Academy Preparatory School and converting 37 Wall Street to 350 rental apartments. Mr. Wilf said that 37 Wall Street's conversion should be finished in October.

When completed, 170 East End Avenue will have a garage and a children's recreation zone that includes a toddler paint room, a computer area for preschoolers, and miniature golf, video games and billiards for older children. The building will also have a squash court and an interactive driving range.