Using data provided by the City of Harrisonburg, the information below is what I am finding on vacant land in the City of Harrisonburg.  Bear in mind that there is a bit more vacant land than referenced below, but I chose to exclude land owned by educational institutions, local government, religious organizations, state government. 

Vacant Land In Harrisonburg:

• 918 Residential Parcels (750 acres)
• 135 Multi-Family Parcels (192 acres)
• 216 Industrial Parcels (484 acres)
• 183 Commercial Parcels (320 acres)
• 14 Large Parcels (88 acres)

This is a total of 1,466 large parcels totaling 1,833 acres.

• The 1,466 vacant parcels account for 10% of the 15,075 total city parcels.
• The 1,833 acres account for 19% of the 9,655 total city acres.
  

Here is a visual to show the amount of vacant land remaining in the City of Harrisonburg: