Todd West of Kenwood California has what he calls the “Kenwood Guestroom/Cottage” up for sale. Here is Todd’s description.
The framing was done with dry sound reclaimed fir. I use two layers of 5/8″ plywood for the sub floor. the exterior and interior walls are also 5/8″ plywood. I textured the interior to look exactly like drywall. the ceiling is drywall. the floor is reclaimed refinished oak. All it needs is a bit of siding and some exterior trim.
The interior ceiling height is 8.5″ at the walls and 9’3″ in the center. The big window is 4’x5′, the dutch door is 36″, and the french doors are 8′ tall x 5′ wide. the interior is painted and trimmed with reclaimed painted redwood 1×4. It is wired for 4 duplex outlets and one porch light. The total height is 10′ 5″. The attached redwood deck is 4′ x 10’3″ it is also reclaimed wood. Over all it is a nice cozy space.
You can view all the pictures of the construction here