Herdon town officials don't want to call it "a building boom," but they are ecstatically predicting house construction in 1983 "will knock the socks off most previous years."

For at least one town in Fairfax County, the era of growth has returned.

Last year, only 27 houses were built in Herndon, compared to 69 in 1981 and 145 in 1980, considered a good year.

In just more than three months this year, developers have taken out building permits for 79 houses, and last week the planning commission unanimously approved preliminary plans for 380 more houses. Industrial construction also is suddenly surging, planning director Peggy Dubynin said.

Most of the new development is in the northwest section of Herndon, near the Loudoun County line. The building is largely houses planned as part of subdivisions begun in the early 1970s but never completed because high interest rates knocked the bottom out of the nation's home-building industry.

Because of the lapse in years, developers must reapply for town approval of their projects. Town building requirements have changed in the intervening years, but the planning commission so far has ruled the developers can build according to the old rules.

Under new Herndon regulations, designed to halt construction of small houses on small lots, a minimum lot size of 10,000 square feet is required for new construction. About 30 of the 250 town houses approved by the planning commission are on lots of less than 10,000 square feet, but the commission waived the requlations and let developers proceed with their early 1970 plans. The Town Council was slated to vote on the projects last night.

Another change, said Pat Mumaw of the building inspector's office, "is that most developers are selling their houses before building them . . . no more building on speculation and then being unable to sell."

Among the major 1970s subdivisions designated for expansion are Benicia Estates on Crestview Drive, proposing 51 new houses; Westfield on the Loudoun line and the W&OD bike trail, proposing 92 houses; Broad Oaks by the former Oak Grove Elementary School, proposing 47 houses; and A&A Homes, just north of the W&OD beside the town golf course, proposing 190 town houses.

A&A and Herndon are settling a court dispute over the type and size of houses for the site.