The Census Bureau’s recently published local-level data includes updated estimates of housing units, current as of last July. While housing unit numbers don’t receive the same publicity as population estimates, they do serve as a useful leading indicator of municipalities’ growth.
Three of the top 10 counties experiencing the largest recent increases in their housing inventories are found in Georgia. Two exurban jurisdictions, Effingham County outside of Savannah and Forsyth County near Atlanta, each recorded increases of nearly 5 percent over the 12-month period ending last July. Several mostly suburban counties in Texas also registered sharp gains.
In jurisdictions that are more reliant on property taxes, construction of new housing can provide a financial boost. Osceola County, a fast-growing area spanning part of central Florida, saw its total property tax base climb about 7 percent over the year, according to the Osceola County Property Appraiser.
Rural McKenzie County, in North Dakota, experienced the single largest percentage increase in housing units of any county nationally. The largest oil-producing county in the state, it added an estimated 733 new units, up more than 12 percent from 2015. While North Dakota's oil production remains below recent highs, it has shown signs of rebounding more recently.
In all, 20 counties recorded increases of at least 3 percent over the short 12-month period ending last July.
| County | % Increase | Increase | 2015 Housing Units | 2016 Housing Units |
|---|---|---|---|---|
| McKenzie County, North Dakota | 12.5% | 733 | 5,859 | 6,592 |
| Osceola County, Florida | 4.7% | 6,449 | 137,065 | 143,514 |
| Effingham County, Georgia | 4.6% | 967 | 20,955 | 21,922 |
| Forsyth County, Georgia | 4.6% | 3,373 | 74,071 | 77,444 |
| Wasatch County, Utah | 4.4% | 529 | 12,021 | 12,550 |
| Williams County, North Dakota | 4.2% | 780 | 18,577 | 19,357 |
| Collin County, Texas | 4.0% | 13,561 | 337,745 | 351,306 |
| Fort Bend County, Texas | 4.0% | 9,310 | 233,131 | 242,441 |
| Dallas County, Iowa | 3.7% | 1,233 | 33,302 | 34,535 |
| Long County, Georgia | 3.6% | 226 | 6,345 | 6,571 |
| Hays County, Texas | 3.5% | 2,570 | 72,912 | 75,482 |
| Rockwall County, Texas | 3.5% | 1,099 | 31,594 | 32,693 |
| Montgomery County, Texas | 3.4% | 6,969 | 202,446 | 209,415 |
| Williamson County, Tennessee | 3.4% | 2,582 | 76,003 | 78,585 |
| Denton County, Texas | 3.4% | 9,744 | 288,152 | 297,896 |
| Williamson County, Texas | 3.3% | 5,977 | 180,987 | 186,964 |
| Hamilton County, Indiana | 3.2% | 3,892 | 120,058 | 123,950 |
| Morgan County, Utah | 3.0% | 103 | 3,381 | 3,484 |
| Gallatin County, Montana | 3.0% | 1,394 | 45,951 | 47,345 |
| Rutherford County, Tennessee | 3.0% | 3,394 | 112,073 | 115,467 |
Several hundred other counties lost slightly more housing units than were added, but none reported losses exceeding 1 percent.
The Census Bureau computes its estimates by considering new residential construction from building permits and mobile homes, then subtracting estimated housing units lost. Housing units are defined to include single-family homes, townhouses, apartments, trailers or single rooms occupied as a separate living quarters. They also include vacant units intended for occupancy.
As one would expect, jurisdictions with notable housing unit gains have also generally enjoyed strong population growth in recent years, which we’ve reported on previously. Over the past several years, mounting increases in the housing inventory are evident across the nation’s fastest-growing counties. New contruction still, however, hasn't kept up with the demand in many tight housing markets, pushing up rents and home prices. An Urban Institute analysis estimated a national shortage of 430,000 more new households that were formed than housing units completed in 2015.
Nearly all counties where the housing supply expanded at the fastest rate since 2010 are located in the South and western U.S., particularly in parts of North Dakota and Texas experiencing an influx of oil workers.
Large counties with the highest percentage increases in total housing units over the six-year period include Fort Bend County, Texas (22.4 percent); Loudoun County, Va., (18.2 percent); and Montgomery County, Texas (17.4 percent).
