All wood from beach and hand-split shakes from driftwood cedar. Bruno Atkey’s incredible repertoire of buildings is on display on pp. 74-95 of Builders of the Pacific Coast (my favorite of all my building books).
Everything he does, all the joints, the design, the materials are to me, perfect. A kindred builder.
(My tower is roofed with shakes that Bruno split from driftwood cedar logs and that Misha drove down here in a van about 7 years ago.)