Wayback Machine: Green Roofs,1933
From Modern Mechanix: "Covering a roof with growing grass might seem fantastic to most persons, but Louis Koefoed, an architect of East Rockaway, N.Y., has found it practical as well as decorative. Since he applied a roofing of sod over tar paper to his dwelling last fall he has experienced a welcome decline in his coal consumption. Moreover, he expects the heat-insulating covering to keep his home twenty degrees cooler next summer. Pipes along the peak of the roof spray the growing grass with water and keep the "lawn" roof green."