Homebuilding in the Twin Cities metro posted a healthy gain during November, the ninth consecutive increase this year.

During November, 474 permits to build 1,099 houses and apartments were issued in the 13-county metro area, the Builders Association of the Twin Cities said Tuesday. That was a 17.6 percent increase in permits, but a 3.8 percent decline in the total units compared with the same four-week period last year.

Though there were more apartment units than single-family houses permitted during the month, housing construction has been increasing dramatically in recent months. Buyers are trying to get ahead of increases in mortgage interest rates.

"Whether it's the warm weather, low inventory of existing housing, or the growing economy we're definitely seeing more families in the market for new construction," said Meg Jaeger, the Builders Association of the Twin Cities 2016 president, in a statement.

During the month, 452 single-family houses were permitted, 20 percent more than last year. At the same time, 647 attached units, mostly upscale rental apartments, were permitted. That was a 15 percent decline over last year.

With more houses being built than apartments, the total value of those permits has increased dramatically. The combined value of all units permitted in the month was $227.5 million, a 19 percent increase over last year.

Minneapolis was the busiest city for total construction with 16 permits to build 466 units, mostly apartments including a 144-unit apartment building at 315 Seventh Av. N. in the North Loop neighborhood that is being developed by a partnership between the Opus Group and Greco. Those figures also included a 198-unit, six-story apartment building that is being developed by a Kansas-based developer near the University of Minnesota campus at 117 27th Av. SE.

Prior Lake was next with 11 permits to build 54 units, followed by Blaine (28 permits to build 53 units) and Norwood Young America (3 permits to build 51 units).

The report comes in the midst of growing concerns about affordability. The average 30-year fixed-rate mortgage topped 4 percent for the first time since 2015, according to the latest weekly survey from Freddie Mac. And on Tuesday, the S&P CoreLogic Case-Shiller U.S. National Home Price Index hit an all-time high during September, breaking the previous peak set in July 2006, suggesting a complete recovery of home prices on a nationwide basis.

For the Twin Cities, the Case-Shiller index during September rose 5.3 percent to 155.39, still below the peak of 171.12 set in September 2006.