While it sounds do-able, as a designer I find the aesthetics don't seem very appealing at all. I always try to accommodate an poster's needs and do appreciate the pragmatism but is there a way to create walls or another room for it? Not only are you washing by your cars, there is dirt and dust out there, which somewhat defeats the purpose. Also what about the spiders that will want to live there because of the humidity and dryer?

Even though that is a fairly small space you could put some decorative trellises just in front of the fence with some ever flowering vines on them. Install a paver patio between them and the windows you hope to transform into doors.. You could also have the wisteria trained onto a pergola that would create a little shade for the patio as well. Some beautiful potted specimens/flowers and a couple of attractive outdoor chairs and you would have created a beautiful "picture" to act as a focus to the room. Additionally you have extra space for entertaining. Obviously the reason the previous owner obscured the window was because there wasn't much to look at. By creating a "view," you change the dynamic of the room as well as getting the light you want. Actual light will brighten the room like no change of floor would.

Id have Raised planter boxes put in around the outside of our yard so my mother in-law doesn't have to spend hours on the ground with a bad back to do the gardening!..

Okay, I eat popcorn maybe once or twice a year so when I do, I go all to H--- in a hand basket. Large Dutch oven, olive oil, fresh popping kernels, medium heat, constant shaking. When popped, humongous stainless mixing bowl, half lb. unsalted butter and salt to taste. Yummmmm. Oh, forgot to say, this ritual usually follows a dinner of sliced tomato and cucumbers. One does need one's veggies! :D