Now that we have done denigrated the poster for his alleged violations of morals, lets get back to the actual LEGAL issue.
The PA Castle/Stand Your Ground doctrine is expressed in 18 PaCS 505.
It's a little to lengthy to post
http://www.legis.state.pa.us/WU01/LI/LI/CT/HTM/18/00.005.005.000..HTM
The synopsis is that PA's law is non unequivocal. There are restrictions and pretty much are limited to that which is IMMEDIATELY necessary to prevent unlawful force (to result in death, serious injury, rape, or kidnapping) against you.
No a shed that is not occupied is not a dwelling or residence under the statute.
Note, you don't even get to hold him at gunpoint unless you believe the above are happening either.