Last year, 34,000 new houses were built in the Washington area, a ratio of 2.43 for every existing 100 houses, down from 2.91 in 1988 and 3.29 in 1987, according to the Chicago Title and Trust Co. Nationwide, the ratio was 1.5, down from 1.64 in 1988.

Washington and Atlanta were the only two cities with more than a million households to record a housing growth ratio higher than the national average.

Naples, Fla., led the country for the third straight year with a ratio of 11.72. San Antonio trailed the 80-city list with a ratio of 0.38.

Office tenants have the upper hand over landlords in rent negotiations in 28 out of 34 North American markets surveyed by Colliers International.

The District and Toronto tied for first place in a list of North American office rental costs, with office space going for an average of $49 per square foot, including operating expenses. Midtown Manhattan ranked third with an average of $45 a square foot, Boston followed with $41 a square foot and Chicago came in fifth with an average of $39 per square foot.

Worldwide, the per-square-foot rental averages were much higher. Tokyo led the list with an average of $192, followed by London City with $154, London West End with $149, Hong Kong, Sydney, Paris, Madrid, Milan and Frankfort, which all had averages higher than Washington's.

The city of Baltimore is seeking buyers for 38 acres in Owings Mills that once were part of the Baltimore Colts' training facility.

Baltimore's Department of Real Estate has set Aug. 30 as the deadline for bids for the property.

Located next to Rosewood Center, a state hospital, the 38 acres are part of a 100-acre parcel in Owings Mills that the city acquired from Colts owner Robert Irsay after the football team moved to Indianapolis. The tract is zoned for light manufacturing use.

Shirley Summers, special projects coordinator for real estate, said the city has decided to retain ownership of the remaining 62 acres, which include practice fields, parking areas and a training facility, for possible use by another professional football team if one should come to Baltimore.

The city is selling the 38-acre tract because it is in a rapidly growing area, the city has no use for it and "we have had a tremendous amount of interest."

Interstate General Co. L.P. of St. Charles, a land development company, has been fined $2,500 for violating sediment control laws.

Interstate General pleaded guilty last week in St. Mary's County Circuit Court to one count of unlawful clearing and grading. The misdemeanor was punishable by up to a $5,000 fine.

IN THE BUSINESS ... Remodeling and residential construction both declined slightly in 1989 from 1988, according to preliminary figures released by the Census Bureau. Homeowners spent $100.9 billion on remodeling in 1989, down 0.2 percent from $101.1 billion in 1988. Residential construction during this period declined 0.7 percent from $139 billion to $138 billion ... Home sales in Prince George's County decreased by 10 percent from 831 units in May 1989 to 746 units during May 1990, the Prince George's County Association of Realtors reported. In the first five months of the year, 3,697 units were sold in the county, down 5 percent from 3,899 in the same period of 1989. The average price per unit increased 6.9 percent from $113,900 to $121,800. The average condominium price was was $72,000, up 9 percent from $66,000 a year ago ... In Northern Virginia, 2,367 home sales were reported in May, up 20 percent from 1,964 in May 1989, according to the Northern Virginia Association of Realtors. In the first five months, 9,412 homes were sold in the region, down 4 percent from 9,800 in the same 1989 period. The average price of units sold in May was $176,600, down 0.3 percent from the $177,200 figure in May 1989 ... Despite the widely reported softness in the local building industry, the Metropolitan Washington Building Industry Association is encouraging its members to attend the group's annual convention at the Frenchman's Reef Beach Resort in the Virgin Islands. For the first time, the trade group is offering rebates of $50 per person to companies that send at least 6 employees ... The National Community Development Association and the Federal National Mortgage Association announced the formation of a fund for low- and moderate-income households. The $345,000 fund, a pilot program involving the purchase by Fannie Mae of single-family rehabilitation loans made by the city government's Department of Housing and Community Development from 1977 to 1987 ... Sigal Construction Corp. completed construction of a three-story, 10,000-square-foot health club at the Four Seasons Hotel in Georgetown ... Harkins Builders recently raised more than $15,000 for Junior Achievement through a bowling contest ... The Real Estate Center at the American University's Kogod College of Business Administration recently received a $100,000 grant form the Homer Hoyt Institute to establish the Metropolitan Washington Real Estate Data Center ... The Harvey Construction Co. plans to renovate and restore a 30,000-square-foot, nine-story building for Strayer College at the corner of 15th and L streets NW, a $1.5 million project ... Coldwell Banker plans to hold a free seminar on the benefits of buying versus renting at the Providence Recreational Center in Falls Church, today from 10 a.m to 1 p.m. ... R. Patrick Casey formed a real estate auction and brokerage company called Coventry Ltd. in McLean ... W.F. Chesley Real Estate Inc. and Horizon Health Management Systems Inc. plan to develop a 180-unit Adult Congregate Living Facility on 35 acres in Upper Marlboro ... The Carey Winston Co. of Washington formed a commercial real estate work-out division to assist owners and managers of under-performing real estate assets with leasing management financial services and sales ... Reiss Construction of Bethesda completed construction of a building at 4301 50th St. NW for W.C. and A.N. Miller Development Co. ... BTR Realty completed construction of a 125,000-square-foot, $15 million building, the second built at the Gateway International Office/Hotel Complex near BWI airport ... Jeffrey W. Carpenter formed Monticello Homes, a custom home builder in Fairfax Station ... Cohen Development Corp. of Columbia completed the first phase of Trade Park 32, a $9 million condominium development in Jessup.

PERSONNEL FILE ... Carey Winston Co. promoted Stephen C. Conely to senior vice president of investment properties ... Lucente Enterprises of Oxon Hill named Anna Lucente vice president for commercial leasing ... Larry Hogan & Associates named Kenneth V. Duncan executive vice president and chief executive ... Shannon & Luchs promoted Yolanda Mamone to vice president.