NEW YORK – Buying an office-to-condo conversion in Manhattan used to be a small bargain compared with a newly constructed condominium, but a new study by CityRealty finds that this is changing as more of the new office-to-condo residences occupy iconic New York landmarks. The study found that in 2014 office-to-condo conversions sold on average at $2,185 a square foot compared with $2,262 a square foot for a newly constructed condo – a 3.5% difference. Five years ago the difference was around 6%. The office conversion units are holding their value slightly better than newly constructed units with the price per square foot up 82% from five years ago; newly constructed condos are up by 78% during the same period. The average office conversion apartment fetched $3.5 million last year, compared with $5 million for a brand new condominium, the study reports. The New York State Attorney General's office – which signs off on condo conversion plans – approved 23 total office-to-residence conversions in 2013 and six in 2014. According to state records, no condo conversion projects have been approved this year. Senior brokers say the interest in developing office conversion units has leveled off as prices for office rent have accelerated. Many of the new conversions are in one-of-a-kind office buildings, including the 31-story Verizon building, designed by famed architect Ralph Walker, and the new apartments in the historic Woolworth Tower. "The prices for office conversion units spiked in 2013 because of a number of pricey closings at the Walker Tower," said Gabby Warshawer, director of research and communications at CityRealty. The average selling price for a condo at Walker Tower, a 55-unit Art Deco building constructed in 1929, was $13.5 million last year at $3,726 per square foot. "Everyone scratched their heads and couldn't understand how we got those prices. It has a lot to do with the architecture and structure of the building," said Vickey Barron, a Douglas Elliman broker for the Walker Tower. "Buyers will collect Ralph Walker building apartments similar to the same way people collect Frank Lloyd Wright houses," Barron added. The Ralph Walker Tribeca, located at 100 Barclay, is the third New York telephone building designed by Ralph Walker to be converted. The building, known for its lavish exterior, launched sales on April 25. Prices range from $3.2 million for a two-bedroom to $11.5 million for a four-bedroom. The next office-to-condo units to launch sales is 101 Wall, a former Art Deco office at 99 Wall Street with waterfront views of the East River. Prices, estimated to be in the "middle luxury" range, are still being determined and sales are expected to launch this summer.