Hello,

I am going to be building an 8x8 "storage shed" this year, I live in Tennessee and I need the interior to stay below 110 degrees Fahrenheit during the summer and just above freezing in the winter. Some but not much heat will be provided by natural sources, it should be enough to stay above freezing as long as I can keep in the heat produced. The difficulty in this project is that everything has to be low-budget as my total budget for the project is $1500. I am going to buy a prefab wooden storage shed for the base construction ($700) so I have to work around that for everything else. Here's what I've got in mind so far to meet my heating, insulation and cooling needs:

Painting it with a highly reflective white paint to reduce solar gain in the summer.

Using white shingles for the roof.

Installing a thermostat controlled solar gable fan.

Installing r-13 fiberglass insulation in the walls

Now I'm also considering a radiant barrier, but i'm wondering if by reflecting radiant heat back into the structure if I wouldn't just be creating an oven in the summer?

Also, do you have any cheap lighting ideas? Right now I'm thinking of going with battery operated led lighting.

I'd put it on an edge-insulated slab with a vented metal cool roof. Insulate the walls with at least 2" of rigid foam on the outside and blown-in insulation in the walls. Seal it up good.

I'd also consider putting some windows on the south side and some water mass inside to collect solar heat. You would have insulated panels to go over the windows if summer heat is a problem. You might get away with just dropping shade cloth, too.