Maryland's Frederick County, already grappling with 18 years of growth, set a record for housing starts last year, raising concern that a new wave of building is underway.

Nearly 3,000 homes, town houses and apartments were constructed in 1989, surpassing the previous high of 2,082 housing starts in 1986, according to a report issued by the county's planning department.

"It's our biggest year yet," said Monika Robertson, a planning department employee who helped compile the statistics. "We expected 2,000 to 2,500 new dwellings. There were an awful lot of apartments built last year in Frederick city."

The growth in housing units has outpaced the county's population boom in recent years. The population of the county grew 32 percent between 1980 and 1990, while housing starts grew 38 percent during the same decade, the report said.

While the type of housing being built remains primarily single-family dwellings, multifamily dwellings and town houses are beginning to account for more of the total housing stock.

"There's more high-density building going on," Robertson said. "That's good because there's not so much spread-out development eating up more land."

Robertson said building activity had cooled since the beginning of the year, compared with last year. However, planning officials predicted that housing and population growth would continue, putting more pressure on schools, roads and public services.

The county population, estimated at 151,860, is predicted to grow to 203,170, or 34 percent, by the year 2000. By the year 2010, there will be 243,600 people living in Frederick County, according to projections.

Most of the new residents are from nearby metropolitan areas, primarily Montgomery County, a trend that officials expect will continue. An estimated 12,074 people migrated to Frederick County from Montgomery County between 1980 and 1987. Another 6,120 moved from Carroll County, the report said.

The new wave of building has puzzled some planning officials, who are not sure why building activity picked up last year.

"Maybe just because the market was right and the value was better in Frederick County than in Montgomery County," Robertson said.

Officials said another burst of building activity could be on the horizon in Frederick County, which has approved construction of more than 20,000 new housing units that have not been built.

To help control rapid growth, county officials are considering a law that would force developers to build roads, schools, sewers and other facilities before housing developments could be approved.

More than half of mortgage bankers surveyed recently report they are making more home loans now than in the first three months of this year, the Mortgage Bankers Association of America reported.

The association surveyed 56 of its member institutions, who together issued $18 billion in loans in 50 states last year, because of a "building perception of a credit crunch" in the real estate industry, said Ronnie J. Wynn, a Montgomery, Ala., banker and president of the association. "We wanted an accurate assessment of current mortgage market conditions," he said.

The survey found that 37 percent of lenders questioned made fewer loans and 11 percent reported no change. Most of the mortgage bankers who are issuing more loans now said they are getting more business because other types of lenders, particularly savings and loans, are pulling out of the market.

Lenders who said loan applications were down attributed the drop to higher interest rates, more competition and weaker demand for housing. A total of 54 percent said they have not tightened the rules for prospective borrowers. Those who are rejecting applications they might have accepted a few months ago said it was because the applicants were weaker financially and interest rates were higher.

A Bethesda firm, Interstate Equities Inc., has bought the Hancock Shopping Center, a 27-year-old outdoor mall in Austin, and plans to spend $10 million on renovations.

The company, whose parent firm owns or controls 13 million square feet of real estate nationwide, declined to say how much it paid for the center near the University of Texas.

Hancock had been owned for more than 10 years by Kingsmere Corp., a Delaware-registered firm controlled by a Dutch pension fund. Kingsmere had announced a major remodeling of the center in 1988 but the work never started.

Hancock was one of the city's first suburban shopping centers when it was built in 1963 by Homart Development, an arm of Sears Roebuck and Co.

Meredith Olson, president of Interstate Equities, said the renovations will give the center about 460,000 square feet of retail space and improve visibility from the street. About 70 percent of the center is leased.

The renovation work is expected to begin later this summer and be finished by spring 1991.

Maryland Department of Environment officials said this week they are seeking $33,000 in civil penalties against two Anne Arundel County firms accused of sediment-control violations at an Annapolis construction site.

Environment Secretary Martin Walsh said the administrative action alleges that Gilligan Development Corp. and Reliable Contracting Co. carried out work without taking proper sediment-control and erosion measures.

State inspectors visited the site several times last fall and the inspections allegedly revealed the companies were clearing and disturbing land without approved plans.

The lack of approved plans reportedly resulted in the discharge of sediment-laden water into a tributary of Aberdeen Creek.

IN THE BUSINESS ... Nationwide, new home sales fell in April for the fifth consecutive month to a seasonally adjusted rate of 542,000, the lowest sales pace since 1982, according to the National Association of Home Builders. Sales were down 10 percent from April 1989 and down 1.6 percent from March 1990. The NAHB predicted annual new home sales this year of 580,000, a 10 percent decline from 649,000 in 1989 ... Word-of-mouth recommendations are the most influential factor in the selection of a real estate firm, a survey for Homeowners Marketing Services revealed ... West*Group Inc. of McLean, in a partnership with Westinghouse Electric, plans to develop an office and retail complex on 30 acres near Baltimore Washington International Airport ... Donahoe Construction Co. completed a 33,000-square-foot addition to the Washington Marriott Hotel, a $5.2 million project, in addition to enlarging two adjoining buildings ... Sequoia Custom Homes L.P. plans to begin construction of the Symphony Place development in McLean ... Fox-Seko Construction Inc. of Vienna completed construction of a 3,000-square-foot Crestar Bank branch in Germantown ... Real Estate Consulting Group Inc. of Washington announced its affiliation with Relocation Professionals Ltd. ... Foulger Pratt Construction Inc. announced a program to recognize individuals and companies in community service ... The National Institute of Real Estate plans to hold a seminar on Tax-Free Exchange of Residential Investment Property on Monday, from 9:30 a.m. to 12:30 p.m., at 1880 Howard Ave., Vienna. The cost is $30.

PERSONNEL FILE ... Glen Construction Co. of Gaithersburg appointed John E. Offutt vice president of construction ... International Developers Inc. named Camilla S. Stroud vice president of community and public relations for Techworld Plaza ... Centennial Contractors Inc. promoted Jack Waschitz to vice president for project operations ... Long & Foster Real Estate Inc. named Roger Ashooh vice president ... The Bethesda real estate advertising firm of Robert Feldman & Associates Inc. named J. Larry Galey vice president.