The housing supply has noticeably expanded throughout several different areas of the country in recent months.

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
SOURCE: Author's calculations of Census Bureau Annual Estimates of Housing Units, July 1, 2015 to July 1, 2016

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).