Helios House, the “green” gas station at Robertson and Olympic (for, er, BP) designed by Johnston Marklee, shown left, top row, is one of many must-see projects conceived in the last few years by Los Angeles architects and now gathered in a book, A5: Los Angeles. The book, edited and written by Berlin-based architect Casey Mathewson and published by ORO editions, was launched last week, June 24, at A+D Museum. Casey Mathewson was there, along with several of the architects whose work is featured in the book,  LA editor Ann Videriksen and yours truly, who wrote the introduction.