But doing everything proper will assure you can add the value to your property when it is time to sell. Un-permitted buildings are actually a problem when you want to sell your property!
Virtual opinion not your best interest contact a contractor who performs that type of service
Lynn911 Dallas Realtor & Consultant, Loan Officer, Credit Repair Advisor
The Michael Group - Dallas Business Journal Top Ranked Realtors
Before coming into real estate, I worked for quite a while in construction, believe it or not, for a general contractor!
Depending on whether you live in the city or county, You want to contact either the city planning dept at 300 Richards Boulevard, 3rd Floor (permits counter) or call them at (916) 264-5011or the county planning at 827 7th Street 225 - Second floor (public counter/applications) 916-874-6221.
They are very helpful and friendly and can probably even refer you to simple plans for your structure. You will need to have those before you can proceed with attaining a permit to build, which you may need. Especially if there is electrical involved (which would make for great resale).
My best to you!!
I'm guessing that the restriction might be in how close you are to the edge of your property in building the structure. this doesn't sound like a structure that would be habitable so you'd have less restrictions.