L&L Holding Co. has announced a major redevelopment of Flatirons's 150 Fifth Avenue, an office tower originally completed in 1890. When the redevelopment is complete the updated office building will feature 227,500 SF of office space complete with the addition of a unique, 2 story rooftop complete with a roofdeck. In all, 150 Fifth Avenue features 11 floors of rentable office space with open floorplans. The ground floor features 15,000 SF of rentable space, floors 2-8 feature 23,000 SF of rentable space each, floor 9 features 21,000 SF, before dropping to 16,000 SF and 14,500 SF respectively on 10 and 11. The redevelopment is being designed by Studios Architecture with Higgins Quasebarth & Partners. OC Development Management will be the project manager. Construction is expected to begin in February 2018 and wrap-up late summer 2019. According to TheRealDeal, Mastercard was negotiating with L&L Holding Co. in May 2017 lease the entire building at 150 Fifth Avenue where they reported average rent for office space in the Flatiron District was $72 SF. 150 Fifth Avenue was originally built in 1888 and was completed in 1890, undergoing a major renovation in 2003 and was selected in 2005 as BOMA’s Renovated Building of the Year.