You've got to want it badly to do it this way," says housewife Brenda Bell of her experience as a general contractor on a $39,000 addition to her Bethesda home.

Had Alvina Long known in advance that her six children would have to camp out dormitory-style in the basement for 16 months, she might have thought twice about how badly she wanted to be her own contractor on the unfinished bedroom wing to her family's 3,700-square-foot Potomac home. But when her contractor grossly underestimated the cost of putting up the first half of the house, she felt she had no alternative but to plunge in where most fear to tread.

Long, Bell and other Washington area homeowners have tackled the task of coordinating and supervising the construction of their own homes -- from hiring backhoe sperators and carpentry crews to ordering everything from studs to stringers. Some even keep time cards and make a weekly payroll. With the high cost of new housing construction and the high mortgage interest rates, the idea of serving as one's own contractor for an addition or a new home is gaining currency. If you can't build it yourself, and you can't afford to hire someone to coordinate the work for you, it may be the only reasonable alternative.

"Let's face it," says Bell, "the average general contractor charges around 15 percent for overhead and another 10 percent for profit on everything. When my husband and I first looked at the drawings for the remodeling and the addition, we were really excited. But the estimates by contractors for the job were just out of sight." Bell figures she saved 30 to 35 percent by serving as the general contractor for an 850-square-foot remodeling and addition. She is quick to say, however, that she had little idea of the challenges in store for her. The unanticipated developments included snow-shoveling her way out of her house on cold winter mornings to cook breakfast in her vacation trailer parked in the driveway.

"I'll tell you one thing," she recalls, "I learned real fast how to relax and take things as they came."

Brenda Bell chuckles as she remembers one incident when she decided not to take things as they came . . . After pricing a long list of materials needed for the job at several different lumber yards, Bell took her list to the yard that had the best prices. "I sat there while this young boy I'd never met before copied it all down. Most of the order was in pieces -- so many of this or that material. But when we got to the plywood needed for the sheathing on the addition, it was listed in board-feet. I guess I was tired -- it was the end of a long day, and I just didn't pay attention . . ."

The oder arrived on three large trailer truckloads a week later. The trucks carried more than 600 4'x8' sheets of plywood, about 530 more sheets than needed for the job. The driver of one truck got out, scratched his head as he looked at Bell's suburban split-level home and asked, "Lady, are you building a condominium here?"

The plywood went back, but Bell had to build a storage area in the crawl space under the addition to store the inevitable extras that cropped up. Marvin Friedman still uses the "little extras" left over after he finished his redwood Potomac home six years ago for firewood.

Pricing all the supplies that go into building a home and getting bids for construction work takes time. As Alvina Long worked her way through contracting the construction of the second half of her Potomac home, she sometimes got as many as six or seven price quotes for everything from doorknobs to dry wall work. "That's where the amateur contractor working for herself or himself has a great advantage over a person who is in the business. I took the time because it was money out of my pocket," she says.

Bell says professional contractors frequently hire subcontractors -- "subs" -- on the basis of the lowest bid, or may select them because of a previous work relationship. The amateur can hire someone who might not be the lowest bidder but who may offer better quality work or good timing. That is not to say an amateur can't and doesn't get badly burned by selecting the wrong person for the job (see the bos on page 42).

In mid-July last summer Phyllis Bilhuber was tearing her hair out because the contractor she had hired to dig the foundation and frame the house she was building was behind schedule.

"The guy is costing me money, she complained, "I've got to move this job along. We're already sold our house and have to move into this one in a matter of weeks. I don't know how we're going to do it."

Saving money was not why Bilhuber decided to serve as general contractor on her South Haven home near Annapolis. Three years ago she had carefully watched the construction of her custom home by a professional builder. When she and her husband decided to build the same house again in another location, she wanted to do the contracting. "It was easier to deal with the subs one to one," she says. "With the builder, I always felt like I was getting excuses for why the work wasn't done or that he was short-changing me for another customer. I decided with that last house that if I had it to do again, I'd do it all myself. I hated not having control over what was happening."

Attorney Marvin Friedman ended up not only as general contractor but spent nearly half his time as a laborer on his Potomac home, largely because he couldn't find a builder who would take on the job. "There isn't a right angle in the house," says Friedman. One dry-wall subcontractor for the job said he'd love the challenge, but his workers would walk away.

For Joy Kramer, a Great Falls, Va., mother of three young children, becoming general contractor for their traditional home meant she could make decisions about costs that could save more in the long run. For example, the Kramers opted for 2"x6" studs in the framing for exterior walls instead of the usual 2"x4" members to permit additional insulation. They also bought insulated windows without the cost of a middleman.

To compensate for plunging into unknown areas, each of the amateur contractors relied on a team of formal and informal advisers. A general contractor needs to make dozens of decisions quickly each day. And although none of the amateur contractors could be accused of being indecisive, when they were in over their heads, they were quick to call for help. Kramer hired a carpenter to serve as her on-site foreman. Bell relied on wekly visits and endless phone calls to architect Richard Condon of Keyes, Condon and Florence. Long referred to elaborately prepared working drawings by architect Jim Hilary who came by for spot checks. Friendman also worked with extensive drawings. His architect, Bill Middleton, came by "when we got in trouble and needed some advice."

"When we made a change from what was specified in the drawings 'without benefit of clergy,' so to speak, we absolved Jim of any blame if we goofed," Long says. Long also read about every aspect of each job. One of her books suggested that at the end of every day she go around and measure the work that had been done against the architects' specifications. At first she scoffed at the idea, but when she walked into one of the bedrooms and discovered that a window had been framed 4 feet from the floor instead of 4 feet from the ceiling, she began making frequent checks.

Kramer says she rarely had difficulties with the fact that most of the subcontractors she dealt with were men. "In fact, the whole experience really blew a lot of stereotypes I had about construction people. They really went out of their way to be helpful."

Long recalled one tense encounter with a tile-setter. "The work he did was so poor that after his first day on the job, I called him and told him not to come back. An older man from Europe, he was obviously not used to dealing with a woman boss and was so floored that I had fired him that he stubbornly mumbled something about, 'All right, I'll come back and work on it some more.' Again, I told him that I meant what I said, that I did not want him back on the job under any circumstances.

"I finally put my husband on the phone and Larry simply said: 'Sir, I don't think you understand. My wife is telling you she doesn't want you back.'"

Drawing on years of experience in buying everything from sofas to socks for a family of eight, Long had little difficulty ordering supplies once she got the hang of it.

"Calling the lumber yards is an art in itself," she says. "In the beginning I didn't know the vocabulary, and I would order things in incredible detail, like: 'I would like 40 white pine 2-inch-by-4-inch boards, eight feet high.' I soon learned the same order could be shortened to 'grimme 40 2-by-4s.'"

Kramer gave her architects' plans to several lumber yards for bids, asking for a list of materials and prices. Brenda Bell's brother, architect/developer Edmund Bennet, did her materials list from the plans, and Long's architect helped make up her lists. All the amateur contractors complained about the high cost of materials and the need to buy in bulk to get builders' discounts.

Supervising the subcontractors meant other challenges. Bell kept a log of everyone's time, but had the carpentry crew she put together herself keep their own time cards. "Once the subs knew I kept a time log, it kept them honest," she says. She was up at the crack of dawn every day with her workers. Larry Long spent almost every weekend working with the carpenters on his house. He saved money (they were paid hourly rather than a flat rate) and kept long coffee breaks to a minimum. Friedman worked on every aspect of his home from digging the footings to countersinking nails in the floor. Kramer loaded her kids into the car several times a day to check on progress. Bilhuber spent more than half her day commuting between her old house and the construction site to be certain workers showed up on time.

To avoid difficulties like workmen who don't show up, Long called every subcontractor the night before he was due on the job to see if he needed anything. The she called at about 6:30 the next morning too be certain they were coming.

The most conspicious difference in the management styles of these do-it themselves contractors was their willingness to serve as "gofers," buying everything from additional nails to coffee, beer and lunch.

In a move few traditional contractors would consider, Joy Kramer baked a cake and held a surprise birthday party for her foreman, an act of kindness that brought tears to his eyes. Bell held an "office party" at Christmas in her trailer for her crew and most of her subcontractors.

Despite this experience under their belts, none of these amateur contractors wants to leap into the business full-time. Says Alvina Long, "It's one thing to go through all that hassle for your own family, but it's quite another thing to do it for someone else." Friedman is not sure he'd want to do it again even for himself. Nevertheless, the experience was rewarding: "Those of us who work with our heads don't have a chance to work with things concretely. There is a satisfaction that comes from doing it yourself."