This one to the right, takes only a few more windows, creating a glass green house. If this were to become a permanent feature in your garden, a framed piece of glass hinged for the door at the end might be better for the neighbors. We are currently having zoning hearings in our county regarding gardens and structures. Please check with your local authorities before building. WE will soon be limited to four feet in height and 25% of a lawn! Outrageous!
Do not be discouraged by your lack of wood and building skills. Get around the internet and you will find alternatives. This is the time to be curious and experimental and a little adventurous.
If you look around your house you too may have a warm spot. If the snow never builds up next to the heat pump that may be the right place for the cold frame. Usually the outside temperature control units are on the "ugly" side of the house, hidden behind fences or in the back away from street side. Cold framing may spruce up the area, give you more use of unused, untraveled area of the yard where your plants can enjoy the extra protection of that "lost" heat.
Now, for those of you who live well North of me and wonder about the poor old cold plants when it snows, some people heat rocks in their fireplaces and place them in the cold frame on a snowy night. But if you are concerned about extreme temperatures, I suggest you dig down. Dig a hole larger than the cold frame and deeper than the frost line. Insulate with straw bales or cinder blocks ( the dead air in the concrete blocks is insulating) and set the cold frame on the bales, return the soil from the hole to the sides of the frame. This photo shows an additional sun amplifying layer of foil that is also insulating.
Make the most of the ground you have to garden. If you have a slope where you do't really plant, use it for your cold frame location. You will get more sun on the slant without having to learn to measure and cut angles.
No matter how you do it, cold frame in your garden and extend the fresh food in the home without running to the store. Start your seeds now, cold frame until it's safe to get those plants in the ground and make the growing season last longer no matter where you are.