FARGO - About one-third of North Dakota's counties lost housing units in the last year, which mirrors the trend in population estimates for the state, experts say.

"I wish we could have positive news," said Richard Rathge, director of the state data center at North Dakota State University. "One has to be cautious with the interpretation, but it reinforces what's happening in our small communities."

Estimates released today by the Census Bureau show a 0.7 percent gain in housing units in North Dakota between July 1, 2001, and July 1, 2002. The total went from 292,014 units to 294,165.

The state ranks 42nd in the country in housing growth.

"A housing unit is simply a place where a person lives," Rathge said. "In some cases, certain housing units are torn down, mobile homes are moved, or a person who rented out units in their home may have stopped doing that."

The five largest counties in the state all showed growth in housing. Housing units in Cass County, the most populous county in the state, are growing at about 2 percent a year, Rathge said.

"That's trending nicely with the population growth," he said. "But you have to be cautious, too, with the type of growth. When you have apartments outpacing single-family units, there can be concerns of congestion, or not enough green space for kids to play … things like that."

The number of apartment buildings isn't as important as the location, said Jim Gilmour, Fargo city planner.

"They're built to provide the type of housing people can afford, but you have to be careful about getting them too concentrated in one area," Gilmour said. "If one starts to deteriorate, people will move out of the area."

The market plays a big factor in construction of apartments, Gilmour said.

"When the vacancy rates go down, the units jump," he said. "Right now with the lower interest rates, some of the builders are looking longer term instead of short term."

Burleigh County is second in the state with 30,134 housing units, up from 29,510 in 2001.

"That's a nice growth rate, to say the least," said Carl Hokenstad, Bismarck city planner. "Historically Bismarck has had a predominance of single family units versus multiple family units, and I think we're seeing a continuation of that trend."

Bismarck is expected to approve a growth management plan in August, which would help the city manage zoning and subdividing of property within 4 miles of the city limits, Hokenstad said.

"There's just a big demand for people to move out a little ways from the city," Hokenstad said. "They still want to be close enough for jobs, but they want more room."

Because counties in North Dakota are so small, it increases the margin for error on estimates, Rathge said.

"These are just ways we can come up with our best guesses of what those housing units are," Rathge said. "And some of the losses may be old, condemned buildings. It doesn't necessarily send a bad signal."