Russ, get someone who knows what they are doing and abides by Codes of Local Govt. agencys for Permits which cost Money.
Now, a little hint, if you have a back stoop for walk out, you ah may be able to add on to it with out all of the Govt BS. Check any Lumber Groups a Major Hardware Stores, they may have Kits at a Reduced Price to buy.
Good Luck Russ, they are nice when they are done!!!!!

Enjoy!