For single wide use 22′ trusses, double wide 32′.
The one in the pic is using 32′ trusses with the 12′ wide building in the center instead of to one side. Length of the building will determine number of runs. Mine is 30′ and will accommodate 12 runs. In the pic it is set up with 9 runs + covered storage aria.
Each run is 4×10 outside under the roof + 4×4 inside with a 4′ wide isle down the center of the building. Price $22,000

My isolation runs (b*tches in season) is two 10×6 runs with a fabricated roof using Igloo dog houses. Each fall I have to replace the $12 tarp on top. Price $900
http://www.hunt101.com/img/486256.JPG