Not quite sure what you are after sscac3d ... but since your house is simple ... here is a simple window shade you can make.
Step 1. Create a sphere ... centered at the orgin and make its diameter just larger than your door or window. I suggest 12 or 14 segments.
Step2. In the front view, using the vertex selection mode, (and if you have the new version 6, turn on Select Through), now select all the vertices for the bottom half of the sphere and go Surface--> Cutaway Object. Delete this object.
Step3. In Top View, other settings as step2, select vertices for one half of sphere, and Cutaway Object again.
Step 4. Set object to 2S(ides). You have a basic sunshade that you see at bistros etc.
If you want to get fancy, in the top mode, select vertices for every other 'rib' and cut each rib away (one at a time).
You only have to cutaway every other ... then just lock them. After cutting them away hide the remains, unlock the ones you cut away and merge them.
If you look at object hierarchy ... should have two objects
Colour one red or green and the other white say.
griff