Those shopping for apartments for sale on the Upper West Side are enjoying a boom of new activity in the area, even in the prized west 70s and 80s. HFZ Capital Group’s The Chatsworth at 344 West 72nd Street is currently undergoing a dramatic conversion that will renovate its 159 apartments to approximately 55 luxury residences. The classic pre-war building, formerly a rental property, will soon join the list of hot NYC co-ops for sale while it will also offer buyers incredible proximity to the many amenities of the Upper West Side.