Depending on the home requirements of your new future buyer, converting the changed living space back to the garage, can be viewed as a positive and as a negative (problem).
If you purchased the home based on size where the sq ft of the converted garage was considered the same value as the normal living space, then converting it back to a garage could possibly lower the overall value of the home. As an example a 2000 sq ft home at say $100 sq ft, when reduced to 1500 sq ft for the garage, would reduce the value by $50k. This is just a simple example with "round" figures as an illustration and not factual.
If garage space is a premium in your location, then it may not be an issue. That said you will gain the garage you want if you proceed.
Janet & Graham Ford
Phone: (918) 798-4428
4105 S. Rockford Ave
Tulsa, OK 74105