Simon Property Group is looking to expand Copley Place, adding 114,000 s/f of retail space and 660,000 s/f of residential space. The proposed addition will push the current retail space into the plaza at Stuart and Dartmouth St. with a 54,000 s/f expansion of Neiman Marcus, which currently resides in 115,000 s/f in Copley Place. Another 60,000 s/f will be added for other shops, restaurants and a public wintergarden. On top of the retail component, the proposed design calls for the addition of 280 units for residential use in a tower--including the lower retail floors--that will top out at 47 stories. The units are currently in the works to be designed as condominiums with the hope of attaining a Silver LEED certification, with features, among others, that include rainwater storage, high-efficiency lighting and operable windows--which naturally ventilate the building in order to reduce the burden on heating and cooling systems--among others, to be determined. The mixed-use facility still needs approval from the citizen advisory council and requires permits from the city. The approval process should last the summer and the developer estimates--if the project is approved--by the fall a timeline can be set for the project's completion.