SEC. 4. RELATION TO CITY PLANNING CODE.
(A) Article 10 of the City Planning Code is the basic law governing historic preservation in the City and County of San Francisco.
This ordinance, being a specific application of Article 10, is both subject to and in addition to the provisions thereof.
(B) Except as may be specifically provided to the contrary in this ordinance, nothing in this ordinance shall supersede, impair or modify any City Planning Code provisions applicable to
property in the Blackstone Court Historic District, including but not limited to existing and future regulations controlling uses, height, bulk, lot coverage, floor area ratio, required open
space, off-street parking and signs.
(Added by Ord. 464-87, App. 11/19/87)
SEC. 5. STATEMENT OF SIGNIFICANCE.
The significance of Blackstone Court Historic District is more historical than architectural, though enough physical evidence of past history remains to create a sense of the former place
and time in this unusual mid-block enclave of five structures on a blind alley. The north line of the ally, Blackstone Court, follows the north line of an early trail shown on U.S. Coast
Survey maps of the 1850's and 1860's, a trail that ran from town toward the Presidio, around the north end of Washerwoman's Lagoon (now drained and filled; so named for the Gold Rush
laundries). The western end of Blackstone Court is the western edge of William Eddy's 1849 Lagoon Survey which set up a grid parallel to Market Street, facing the view through the
Golden Gate. On a lot alignment perpendicular to the north edge of the old trail, 9-11 Blackstone Court appears to date from the 1850's because of its Gothic Revival veranda and its interior
plan and finish. It is first documented on its site in 1893 (possibly moved to clear a street right-of-way designated by the Laguna Survey of 1889-91). Before 1899 it was raised a story by
the Favilla family from North Beach, very early Italian-American residents in what became the Marina District. Abraham House, 30 Blackstone Court, was constructed in 1885 by Charles
Abraham, and enlarged by him in 1905. Abraham was the horticulturally significant founder of Western Nursery, which operated on most of this block from 1885 to 1947. It was the last
expression of the Cow Hollow/Marina District agricultural enterprises. An Australian peppermint tree and a Monterey Cypress app