Thanks to the iPod, MP3 players and online movie streaming options like Netflix, stacks of unused CDs and DVDs are gathering dust on shelves all over the world.

You might not realize it, but DVDs and CDs are considered hazardous waste by government collection programs. This means you should never simply toss them in trash, and can only recycle them in programs designated for electronic and household hazardous waste. If you are feeling creative, you might want to skip the recycling bin and put those shiny discs to use in your own green-building project. The perfectly flat discs can be used as a roofing material for any structure that has a wooden-board roof, like sheds, doghouses, lean-tos and porches. Instructables has a great DIY guide for creating this unique type of roof, complete with directions on how to arrange the discs in a honeycomb pattern that will allow you to use the least amount of nails to secure them in place. The strategic method of drilling and arranging the CDs used in this guide means no water runs through the holes in the CD, keeping everything safe and dry in the structure below. When assembling the roofing “shingles,” you’ll have to decide whether you want to expose the top or bottom of the disc. Choosing to display the top of the CD or DVD will result in a colorful patchwork design because all the labels and printing on the discs will be exposed. Displaying the shiny bottom of the discs will help to keep the structure cool by reflecting sunlight, but could blind your neighbors on a particularly sunny day!