The idea is that the platform will be made to fit both hutches, side by side, and constructed from reclaimed 4 x 4 and 2 x 4 treated boards. The roof will be a 2 x 4 treated frame with supported plywood in the bottom. Instead of going with more corrugated asphalt roofing, I'm going to try a green roof. A waterproofing roofing membrane will go on top of the plywood. Then a thin layer of gravel for drainage, landscaping fabric, good quality potting soil, and finally plants will follow.
The hutches will be sandwiched in between the elevated frame and the green roof with the option of adding in a plywood floor when the weather turns to cold for the nesting boxes to do the trick. In theory the roof frame would be easy to remove to access the hutches or add the plywood floor as needed. The weight of gravel, soil and plants not to mention the lumber could add up quick. I'll keep you posted.