"Boy," pastor Robert Himmelman of Christ Lutheran Church remembered saying last year, within earshot of parishioner Tom Schaaf, "would it ever be nice to have a place for the intern to live right here at the church."

Himmelman mentioned the recollection on a recent Saturday as he stood in the shade behind his church on Meredith Drive in Fairfax City, dressed in a faded red T-shirt, aging jeans and workman's boots. Around him were 40 members of the congregation, each of them attired likewise - there to spend the day putting up the prefabricated frame of a two-story "mini-parsonage" for the pastoral intern arriving this September.

He glanced across the lot at Tom Schaaf, the 51-year-old house builder, management consultant and retired Navy commander who was supervising the all-volunteer work force. "I guess you have to be real careful of what you say around Tom Schaaf," Himmelman said, grinning.

The pastor had several reasons to smile.

First, for $26,000, the church's yearly interns (and their families) will get a two-bedroom, two-story home, which Himmelman estimated could have cost about $70,000. The savings are the result of the volunteer labor (more than 70 congregation members have donated time so far), prefabricated components (including Fairfax City's first pressure -treated wood foundation, while parishioners raised in about two hours the weekend before) and a building site already owned by the church.

All work on the house - including roofing, siding, carpentry, landscaping and interior finishing - is being done by parishioners on Saturdays and weekday evenings, Schaaf said.The only subcontractor hired by the church will be installing a heating and air conditioning system, he said.

Secondly, Himmelman said, completion of the two-bedroom home in August will end the annual "hassle" of trying to find housing for the interns, trying to find housing for the interns, who in past years lived in apartments. The coming year's intern, who will arrive from a Gettysburg, Pa., seminary a month after the home is completed, is the first to bring both wife and child, Himmelman said, but the future monthly mortgage payments will be lower than the monthly rents the church now pays for intern housing.

Finally, Schaaf's 12-member church building committee, which planned construction of the house through the past year, succeeded in getting church members out of the house and into a project done primarily for the love of their fellow man. And that's enough to make any clergyman smile.

The recent Saturday gathering was often referred to by participants as "the barnraising" - and it had all the enthusiasm, good humor and hard work associated with one. Facing the house was a large hand-lettered sign propped up on an easel and titled "Objectives List." Number one said, "Raise Walls;" number two, "Set Beams & Trusses," number three, "Sheath Roof," and so on through number six, which said, simply: "Complete 1-5 Before Dark."

Work was to begin at about 10 a.m., and it didn't start late - it started 45 minutes early. Whenever a sledgehammer was needed to edge one of 18 prebuilt wall panels into a tight fit, the duty went to the nearest free hand. The other hands were busy holding up the panel or bracing it with a 2 by 4 from the ground or nailing and bolting it when it was finally in place.

Someone had brought a video tape deck and camera "to record this historic event," and when the last wall panel was ready to go in, Schaaf was handed a microphone and asked to do the play-by-play of the all-important final fit. Schaaf went to work with the microphone and the men inside did the same with crowbars, sledge hammers and back muscles. When the panel finally slipped into a vertical fit, a spontaneous cheer went up.

The local Aid Association for Lutherans served hamburgers, soft drinks and bandaids to all, whether they came to hammer, brace, lift or just to watch - volunteers such as wheelbarrow man Wilbur Peterson, who spends his nonhouse-building time as comptroller at Andrews Air Force Base, or parishioner Mel Davis, administrator of the U.S. Soil Conservation Service and one of Saturday's many carpenters.

"This doesn't happen very often," said volunteer Charles Leach, who normally works on the road for VEPCO, and who will be in charge of electrical installation in the house. "Something like this is more related to a country church than a city church like ours."

"I think it's a great way to build a house," said Rodger Swanson, a Herndon computer systems designer who, though he said he enjoys building things in his spare time at home, hadn't ever tried anything on such a grand scale before."It seems so easy this way."

Agreeing with Swanson was Bennett Barnes, president of Barnes Homes of Charlottesville, suppliers of the prefabricated wood components used to build the home. Barnes stayed to watch just about all of the five "objectives" carried out and beamed through it all. Barnes Homes, he said, has supplied the materials for some 250 homes in almost 10 years - but this was his first parsonage.

"It's great, I love it," Barnes said. "Come on, let me show you the basement . . ."