Housing construction starts in Canada plunged to their lowest level in six years last month and could go even lower over the next few months before bottoming out, Canada Mortgage and Housing Corp. reported this week.

The federal housing agency blamed high interest rates, the buildup of the inventory of unsold housing units and low consumer confidence. The slump last month broadened, spreading from single-family homes to apartments and condominiums, the agency said.

A spokesman for the home-building industry said the housing slump is the worst since the 1981-82 recession and estimated that as many as 250,000 people in building and related industries could now be out of work.

The federal housing agency said there were only 12,019 building starts last month, which if adjusted for seasonal variations and spread over 12 months works out to an annual rate of 137,000, down 16 percent from August and the lowest level in six years.

"On a regional basis the decline was widespread, with the exception of a slight increase in Newfoundland and no change in Alberta," CMHC said. "Sharp declines in Quebec and British Columbia contributed to the overall lower level of activity in September."

Gord Thompson, president of the Canadian Home Builders' Association, said, "Housing-start numbers at this level are disastrous ... . The employment situation is pretty grim."

The numbers also reflect the fact that houses aren't selling.

"There could be as many as 200,000 to 250,000 people across Canada now out of work directly and indirectly related to the residential housing industry," Thompson said.

"High interest rates were what started the downward spiral," Thompson said, something the association pointed out to Finance Minister Michael Wilson and Bank of Canada Governor John Crow last spring.

"They didn't listen to us at that time," Thompson said.

Adding to the industry's woes is widespread gloom among Canadians who, even if they can afford to buy a house, are reluctant to do so because they are worried about the future of the economy and their finances, Thompson said.

What's important now is that the government get interest rates down now and that it reassure Canadians that the economy will improve, he said.

Mark Burchinshaw, CMHC economist, said the stock of new but unsold houses is very high and builders have very little incentive to construct more.

He said it will probably be the middle of next year before there is any increase in building activity.

The Second U.S. Circuit Court of Appeals in New York has affirmed a decision of a lower court to prohibit a Manhattan church from building a 47-story office building on the site of its community house on Park Avenue, according to the October issue of Historic Preservation News.

St. Bartholomew's Church has been trying for more than 10 years to tear down the building, which is protected by the New York City Landmarks Preservation Commission.

Suffering from lowered church attendance and declining revenues, the church planned to put its land to more lucrative use. It challenged the commission's decision prohibiting demolition on the grounds that it violated First Amendment freedom-of-religion rights and constituted taking of property without compensation.

Historic preservationists claimed victory in the decision, saying it gives cities the right to protect historically important religious buildings.

IN THE BUSINESS ... The Subcontractors and Suppliers Council of the Suburban Maryland Building Industry Association named its Builders of the Year: The C-I/Mitchell & Best Co. of Rockville won the large-volume builder award, Sandy Spring Builders of Gaithersburg won in the medium-volume category and Natelli Associates of Gaithersburg in the small-volume group ... New home sales leveled off nationwide in August at a seasonally adjusted annual rate of 550,000, down 1.4 percent from the previous month, the National Association of Home Builders reported. Compared with a year ago, the August sales rate was off 23.5 percent. NAHB is projecting a total of 543,000 new home sales in 1990, down 16 percent from the 649,000 sold in 1989 ... Home sales in Prince George's County totaled 441 units in September, down 24 percent from 587 units in September 1989, the Prince George's County Association of Realtors reported. Year-to-date sales totaled 6,002 units in the county, down 11 percent from 6,751 units during the first nine months of 1989. The average residential sale price was $123,100, up 6.6 percent from $115,400 last September ... In Howard County, single-family sales totaled 216 in September, down 17 percent from 263 units during the same month a year ago, the Howard County Association of Realtors reported. Year to date, 2,243 units have sold in the county, up 4 percent from 2,155 during the same period of 1989. The average price was $109,390 ... Black Walnut Run Estates, a 90-home-site "Passive Solar" subdivision in Orange County, Va., won the State of Virginia's top energy award. The 240-acre project was designed and built by Joseph E. Butler of Butler Engineering & Design Consultants Inc. of Fredericksburg ... Hazel/Peterson Cos. and Cavalier Land Development Corp. are planning to build WestMaren, a condominium development of 280 units in Loudoun County priced from $76,900 ... The Bob Porter Co. Inc. of Gaithersburg has begun construction on a 32,000-square-foot corporate headquarters in the Gaithersburg Airpark ... Real estate agents who have sold one of Town & County Realtors T&C-10K properties are eligible to win $10,000 in a drawing. The program is a new marketing technique developed by Town & Country as an incentive for agents.

CALENDAR ... Women in Retail Real Estate is planning a seminar on Shopping Center Development at 6 p.m. Monday at the Ramada Inn in Bethesda. For details, call 202-966-7242 ... The Fairfax County Economic Development Authority announced a tour of U.S. Route 1 south of Alexandria to Fort Belvoir on Tuesday. The tour, intended for anyone interested in development in the area, will showcase revitalization opportunities for members of the residential and commercial development community ... The Northern Virginia Association of Realtors has scheduled a convention and trade show for Tuesday and Wednesday at the Radisson Mark Plaza Hotel in Alexandria, including a Tuesday speech at 6:30 p.m. by Sen. John Warner (R-Va.) on the Persian Gulf crisis and how it affects the real estate market ... The Home Builders Association of Maryland's Sales and Marketing Council and the National Association of Home Builders are planning a two-day seminar on Marketing Management for the Home Building Industry Thursday and Friday at the BWI Airport Marriott. Walk-in registration will cost $95. For more information, call 800-368-5242, ext. 347 ... W.C. and A.N. Miller Realtors is planning to give away more than 5,000 pumpkins to the public at their Bethesda office next Saturday starting at 9 a.m. ... The Washington/Baltimore Regional Association and three local chapters of the National Association of Industrial and Office Parks are planning a panel discussion, "Baltimore-Washington Real Estate Outlook," Oct. 23 from 8:30 a.m. to 1:30 p.m. at the Johns Hopkins University Applied Physics Laboratory's Kossiakoff Center in Laurel. For reservations, call 301-685-0155 ... Long & Foster Realtors is planning to hold home-buying seminars at many of its offices Oct. 23. For more information, call 703-359-1510 ... The Northern Virginia Building Industry Association's Remodelers Council is planning a free seminar, "Surviving the Remodeling Jungle: How Not to Get Taken," at 7 p.m. Oct. 23 at the Consumer Housing Library in Fairfax. For information, call 703- 273-9886 ... ERA Gallagher & Co. is planning a free seminar on its Seller Security Program at 7 p.m. Oct. 23 in Bethesda. Call 301-986-0077 for reservations ... The Northern Virginia Apartment Association is planning a leasing seminar for leasing consultants Oct. 24 at the Sheraton National Hotel. The full-day course costs $220 for non-members ... Acadia Appraisal Associates of Fairfax is planning to hold free, weekly introductory seminars on real estate appraisal.

PERSONNEL FILE ... West Group Inc., a McLean-based developer, named three new vice presidents: Peter A. Ognibene was promoted to vice president and treasurer; Francis X. Chambers Jr. was promoted to vice president with the responsibility of initiating and overseeing new and existing projects; Alice Starr was promoted to vice president for marketing and communications ... The Federal Home Loan Mortgage Corp. named Debra Rose-Johnson vice president of compliance operations ... Kenneth M. Tuchtan was named senior vice president of operations of Realty World Corp. of Fairfax. His name was misspelled in the Sept. 22 Real Estate Notes column.