Twin Cities homebuilders are having their best April in nearly a decade.

Throughout the 13-county metro area, 383 permits were issued to build 788 units, including rental apartments and single-family houses, according to data collected by the Keystone Report for the Builders Association of the Twin Cities.

"This is the steady growth that we were hoping to see this year," said Meg Jaeger, president of the Builders Association of the Twin Cities and a custom homebuilder.

After several years of tepid gains, homebuilders are reporting slightly stronger demand that's being driven in part by deepening confidence in the economy and a lack of existing homes for buyers.

"With the Twin Cities' existing housing inventory at a record low," Jaeger said, "we believe this upward trend in new construction will continue."

Apartment construction continues to drive the recovery, with demographic forces and a two-decade drought of new apartments fueling demand for upscale rentals throughout the metro.

On Thursday morning, the U.S. Census Bureau said the homeownership rate nationwide continues to slip, according to its quarterly survey. But with household formation on the rise, the homeownership rate in Minnesota bucked the trend, increasing slightly to 74.5 percent.

Multifamily housing represented 52 percent of all planned units this month, up slightly from the previous month.

Apartment construction has a big impact on the permit numbers, creating volatility from month to month depending on how many large buildings were permitted.

A single permit can be issued to build more than one unit.

This month, for example, those permits included one for a 156-unit building at 100 Hennepin Av. S. in Minneapolis that is being developed by Ryan Cos. for Shorenstein Realty of San Francisco.

There has also been a recent flurry of suburban rental projects for seniors and low-income renters.

The April gains were in part due to a particularly slow spring last year. During the first four months of this year, single-family permits were significantly higher than last year at this time.

So far this month Minneapolis had the most planned units (243), followed by Prior Lake (178) Blaine and Lakeville (23 units each) and Plymouth and Otsego (19 units each).

Commercial builders in the region have also been exceptionally busy with everything from churches to warehouses. On Thursday, Dodge Data & Analytics said that total nonresidential construction spending in the 13-county metro during the first quarter increased 15 percent to $380 million.

For commercial and residential builders alike, the primary challenge in the coming months will be rising construction costs, especially when it comes to labor and land.