Utah is not what real estate agents like to call a "hot market" for residential property sales.

On the other hand, if keeping the average price of a home down where first-time buyers still have a chance at the American Dream, then the state is not doing too badly. It might be tough to sell a house in Utah these days, but relative to the rest of the country it's pretty easy to buy one.Century 21 Real Estate Corp. has just completed a survey of its 6,200 offices nationwide and has come up with an average selling price of homes (single-family, multi-family combined) based on some half-million home sales. Utah came in at only $13,000 above the lowest average price (Iowa) and a whopping $154,274 below the highest average price (Hawaii).

The average selling price of homes sold by Century 21 offices in Utah was $59,664 - well below the $74,921 average selling price cited by the Salt Lake Board of Realtors ($79,602 for single-family homes alone) which ranks only the Salt Lake metro area.

Iowa's low average selling price was $46,631, followed by North Dakota, Oklahoma and Arkansas, all with average prices below $50,000. Hawaii's $213,938 was followed by Massachusetts, Connecticut, New Jersey and California, which ranged in descending order from $177,043 to $149,459.

Utah was among 14 states with average selling prices between $50,000 and $60,000. In ascending order they were South Dakota, Idaho, West Virginia, Montana, Oregon, Louisiana, Kansas, Nebraska, Wisconsin, Wyoming, Missouri, Alabama, Utah and Kentucky topping out at $59,980. Utah was 17th lowest in the nation in average selling price.

Century 21 claims that its figures are a good representation of national trends because its collective sales of $60 billion worth of real estate sold last year represent about 11 percent of all residential sales nationally.

Utah's low average sales price seems to be reflected in builders' unwillingness to build new homes on speculation. In its real estate sales activity rankings for 1988 - informally labeled the "Hotness Index" - Lomas Mortgage USA ranks Salt Lake City fifth from the bottom among 53 major U.S. markets in single-family home construction last year. Only Tucson, Albuquerque, Austin and San Antonio, in descending order, had fewer than Salt Lake's 3,422 building permits for new housing.

In construction of multi-family homes, Salt Lake was dead last with only 152 permits for the year - further proof of the depressed condominium market locally. When single-family and multi-family are combined, Salt Lake's total of 3,574 building permits was fourth from last. Only Albuquerque, Austin and San Antonio, in descending order, had fewer.

At the top of the single-family scale was Riverside-San Bernardino with 43,029 building permits taken out, Washington D.C. with 29,264 and Atlanta with 28,518.

Lomas' "Hotness Index" of the nation's 53 best markets for housing construction last year ranks Salt Lake sixth from the bottom with a 3.4 rating. Less "hot" than Salt Lake were Austin, Pittsburgh, Houston, New York-Long Island and San Antonio.

Las Vegas' 44.1 Hotness Index for housing construction led the nation, nearly double the next highest, which belonged to Riverside-San Bernardino with a 24.6 rating and Orlando with 23.1.

Of the sizzling Las Vegas market, Lomas notes that in each of the four quarters of 1988 Las Vegas builders took out 44 new building permits for each 1,000 residents. "This is a rate that cannot be sustained for long without serious over-building," Lomas said.