I would take the time to read through your neighborhood's CC&R and try to find any reason why your current plans were turned down (maybe its too big, wrong location, etc).
You can use it as a guide to change your planned dimensions and structure. If you feel that you have modified your plan accordingly to comply with the restrictions, then resubmit your application and include copies of the pages of the CC&R that apply to your current restrictions.
Underline or highlight each sentence/paragraph that applies to your case.
Please note that not all HOA staff are the same.
Some are pretty good and perform due diligence and work with you to get within code. The current HOA management in our neighborhood was pretty pleasant to work with and are knowledgeable with building/neighborhood codes. They would tell us why the proposal is "out of code" and gives us recommendations on how to correct the plans.
Some people (like the ones from the HOA from my old home) are just in it as a hobby and want to have something else on their resume other than "Stay at home spouse".
They get flustered when they see blueprints and plans submitted to them and think of the quickest reason to reject the plans.
They would scan through the CC&R, see the words "Structure" and "Restriction" and decide that all additional structures are absolutely prohibited.