This is a 7'x12' greenhouse I made out of old windows from my home, I used poly-carbonate plastic roof panels and cedar shakes.
If you're looking for a roof that lasts long and is easy to install—try Interlocking metal roofing. It's expensive but it works great and looks fantastic!
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How to Cut Corrugated Metal Roof Panels (with Pictures) | eHow
Solar Roof Panels - Standing Seam Metal Roof can easily be integrated with solar roof panels that convert solar energy into electricity, which provides free energy for your home. This can be a great element of sustainable building design.
DIY Storage Shed Building Tips Order Cut-to-Length Steel Roof Panels
SoloPower has developed highly efficient solar thin-film panels that can be set up on metal or flat roofs.
copper penny roof photos | MELCHERS GREEN SNAPLOCK ROOFING PANEL, WITH WHITE SIDING; WHAT A GREAT ...
Shop Tuftex Polycarb 2.17-ft x 8-ft Corrugated Polycarbonate Roof Panel at Lowes.com
Photovoltaic thin-film laminate is integrated with standing seam metal roof panels for a sleek appearance. It’s bonded directly to the standing seam roof panels in the factory. Found an updated link.