This door is part of the “Church of Holy Communion and Buildings” complex, which was designed by architect Richard M. Upjohn and built in 1844-50 This site here has lots of pictures of it along with the following wonderful description of its history:
Designed in a rustic Gothic Revival style, this modest church was built for an Episcopalian congregation when the neighborhood was a remote, second-rate residential district surrounded by fields. Its asymmetrical composition, brownstone construction and simple ornament all function to emphasize its picturesque character. The Medieval details on the church and rectory echoed those of an nearby group of row houses which were a rare example of Gothic Revival residential architecture in the city. Saved in the 1960s by a landmark designation sought by its last minister, the Church building has since been used as a drug rehabilitation center and, subsequently, as a dance club called the Limelight.
The “remote” neighborhood it was built in? Today’s Sixth Avenue and 20th St. The church and associated buildings have also moved on from housing the Limelight; in 2010 it was transformed into a kind of mini-mall. Read all about that transformation here.