I suspect that an appraisal from your Township would make a visit to your home and assess the remodeling done on your home. Your designation of a particular room may have an impact but generally speaking an adjustment upwards should be expected in your property tax assessment.
I am not 100% clear on whether the Usage designation has an impact, but I would call the township and ascertain how reassessments are made from remodeling a home and whether or not Usage designations have an impact. This is very important for you to find out as property taxes are paid every year and this could be potentially very costly to you.
Good Luck!