The Washington area, with 21,940 homes built in 1979 and 1,076,700 households, had a home building rate of 2.04 new homes per 100 households, placing it 26th among 53 U.S. urban markets studied by Chicago Title Insurance Co.

The markets studied included the largest U.S. cities in terms of residential construction, plus selected medium-size active markets. The study analyzed construction activity by comparing the number of new homes built per 100 householdls in markets. A ratio was established by dividing total new units by the total number of households in hundreds.

Nationally, 1.7 million homes were built and there were 79.6 million households, giving a national rate of 2.19 homes per 100 households, according to the research done by the firm that insures property titles for homeowners and lenders.

West Palm Beach, Fla., with 26,560 new units and 202,000 households, had a rate of 13.15 new homes built per 100 households, putting it first on the list.

Fort Myers, Fla., with a construction rate of 9.71 was the second most active market in the nation. Next came Las Vegas, 8.93; Phoenix, 7.02; Sarasota, Fla., 6.78; Tucson, Ariz., 6.15; Houston, 5.68; San Bernardino/Riverside, Calif. 5.52; Dallas/Fort Worth, 4.52, and Seattle, 4.25.

"These figures demonstrate the continued boom in housing demand in the Sun Belt, with higher-than-average residential construction in Florida, Arizona, Texas and California," said John Pfister, vice president and manager of market research for Chicago Title.

Comparing 1978 and 1979, the study shows that the ratio of construction activity declined for most areas last year. However, some markets did move against the trend in 1979, including West Palm Beach, Tucson, Tampa, Atlanta, Miami and New Oreleans.

The largest relative declines in the nation occurred in Chicago, Milwaukee and St. Louis.

Pfister said the method used by Chicago Title to gauge construction activity offers an accurate view of real demand in an individual market because it provides a ratio that can be computed and graphed on a yearly basis to show how a market performs compared to the U.S. average or other markets.

"The ratio does not rely on percentage increases or decreases, which are very volatile, or on raw numbers, which can be misleading," he said. For examaple, Pfister explained, Tampa with 25,400 new units and Chicago with 27,680 units had roughly similar totals for new residential construction in 1979.

However, because Tampa has 631,300 households and Chicago has 2,535,400 households, Tampa's construction activity rate was 4.02, almost double the U.S. average, while a 1.09 rating for Chicago reflects far less demand in relation to size.