I lived on the 1900 block of 22nd Avenue from 1979-1997. Almost all the homes started out as 2BR/1BA floor plans built by Costello Builders circa 1940. Over the years, some owners added the traditional room and bath down, and by the late 1980s, some were adding up. Now I see one of my neighbors' houses (1915-22nd Avenue) listed for $1.58 million. The tunnel entrance and most of the garage have been turned into a wide-open living space (family room, dining room, kitchen, bath) opening onto a small outdoor patio. The main floor living room remains, along with the 2 bedrooms, but the original kitchen and the dining room have now been turned into bedrooms and the original 1 bath on the main level has become 3 baths. I can only imagine how many cars are going to be parked on the street! Is this the new standard for the once-quiet Sunset neighborhood?
http://www.sfrealtors.com/US/Home-For-Sale/CA/San-Francisco/Parkside/1915-22nd-Avenue/20015474.html