I think the critical piece of the question here was "in the Fan." The Fan is a designated historic district, and the entire neighborhood is on the National Register of Historic Places. Additionally, it is the largest contiguous collection of Victorian architecture in the United States. Garages here are worth a LOT more than in the standard neighborhood. Many garages don't even fit full-size cars, since they were originally carriage houses. However, even smaller garages are still prized because of the storage capacity they afford. The Victorians just didn't have as much "stuff" as we do!
My broker, who has lived in the Fan for 25+ years and been in real estate for over 34 years, says a garage adds somewhere between $25,000 and $100,000 in value, depending on the size of the garage and the price point of the home. For example, a Monument Avenue home without a garage would be priced $100,000 less than a similar home with a garage. A smaller, attached side street home could get an additional $25,000-$50,000 in value from a garage.
Hope the information helps, happy buying! MLS... more