ZAC Posen is moving on from duds to domiciles. Sources said the fashion designer is teaming with architect Morris Adjmi to create a luxury boutique residence just south of the Flatiron District. Posen, who also has a furniture line coming out next year, will be in charge of creating the fixtures, trims, and furnishings of the units, which will go on sale in December. Adjmi also designed the High Line Building now being built over the new park at West 14th Street.