Glossary

Difficult Development Area (DDA)

Also known as: DDA

A HUD-designated metropolitan or non-metropolitan area -- determined by the relationship between local fair market rents, construction costs, and area median gross income -- where LIHTC construction and land costs are high relative to incomes, qualifying projects there for the same up-to-30% eligible basis boost available in Qualified Census Tracts.

Unlike a QCT, which is defined by the income and poverty profile of a tract's residents, DDA status reflects the cost side of the equation -- HUD calculates a ratio comparing an area's Section 8 Fair Market Rent to its area median gross income and ranks areas nationally, designating the highest-cost areas, subject to a statutory population cap similar to the QCT limit, as DDAs for the following year. Because DDAs are frequently concentrated in expensive coastal metros, Alaska, Hawaii, and other high-cost non-contiguous areas, the designation functions as a practical acknowledgment that a flat credit calculation applied to the same nominal construction cost nationwide would systematically undersize affordable housing feasibility in the country's most expensive markets absent the boost. As with QCTs, DDA maps are republished annually and must be verified against the current list; and notably, while the QCT/DDA boost applies automatically to a qualifying 9% competitive allocation, a bond-financed 4% deal only receives it if the issuing agency affirmatively finds the increase necessary for the project's financial feasibility -- a discretionary determination that is not guaranteed simply because the site sits within a designated DDA.