Historic tax credits (HTC) were initiated into the federal tax code in 1976, making it one of the top federal programs which  has helped preserve America's historic structures.

After an amendment to the federal tax code in 1986, 20% of the total construction costs are eligible for credits on both the state and federal side. (Ex. – If construction is $3,000,000, 20% state level is $600,000, 20% federal level is $600,000. This is a total of $1,200,000 in tax credit eligibility!)

Your tax credit is administered through the National Park Service and the IRS. Tax credits you'll receive are 20% of all your qualified rehabilitation expenditures, otherwise known as QREs. National banks have authority to provide financing for these projects.

Details on the Application Process
There is a three part application process.

In Part 1 of the application, you'll provide details on the Evaluation of Significance. This helps determine whether your storage unit property is eligible to receive funding or tax credits.

Part 2 is Description of Rehabilitation, which will determine if the improvements being made will compromise the existing historic significant characteristics of the building.

Part 3 is Request for Certification so you can get an official historic preservation certification from the State Historic Preservation Office.

One copy of the application will be going to the State Historic Preservation Office and the other to the National Park Service. The State Historic Preservation Office generally reviews Parts 1 & 2 of the application first and within 60 days.

Qualifications and Exclusions
The money you receive is required to go toward the rehabilitation, with the cost of rehab exceeding the pre-rehabilitation cost of the structures.

Look out for some exclusions on the IRS page about HTCs. Some expenses you're facing aren't covered with the funding. For instance, you can't use the tax credits on acquisition costs, carpeting, decks, furniture, or parking lots as just a few examples. 

Be sure to hire a consultant to assist you to study the rules carefully before you spent time filling out the application.