MILLARD FULLER seems indifferent to the 96-degree weather as he nails sheathing under the eaves of a house that four hours earlier was nothing more than a slab of concrete on the ground. Mr. Fuller, a lanky Southern lawyer, is busy practicing what he calls the ``theology of the hammer,'' a type of practical Christianity that led to his founding Habitat for Humanity 11 years ago. The organization has one simple goal: the elimination of substandard, run-down housing everywhere.
Some 300 other Habitat volunteers from every corner of the United States and two Canadian provinces joined Mr. Fuller last week in this latest venture - a race to build 14 houses in just five days for poor families in the neighborhood. They have called the Charlotte project the ``Miracle on 19th Street.''
Farther north, a ``Miracle on Blue Hill Avenue'' promised 11 town houses for the less fortunate of Boston during the same week. And in 150 other US cities and in several developing nations as well, more Habitat construction was taking place. Because of the intense effort, by week's end about 300 families for the first time would know the joy and dignity that come with home ownership.
Habitat for Humanity's worldwide home-raising programs go on all year long. But they are generally less orchestrated and publicity-oriented than the one last week.
Barbara Yates, founder of the Northeast chapter of Habitat, explains: ``We felt a need to get our message across to the general public in a dramatic way. We have to let people know that there is a practical solution to the housing problem.''
Habitat for Humanity is not a charitable organization. ``We give away nothing except a great opportunity,'' a Habitat volunteer says. The opportunity is a significant one, however: a new home at cost with an interest-free mortgage loan repayable over 20 years.
To qualify, families have to earn enough to make the small monthly payments, but not so much that a bank would deal with them. They are also required to put several hundred hours of ``sweat equity'' into their own homes. And they're often required to invest time in the construction of a neighbor's house.
Considerable praise is heaped on Mr. Fuller for his selfless ``no more shacks'' housing campaign. But Fuller, a crusader at all times, gives God the credit - as well as the family crisis that precipitated his dramatic change of direction.
Until his wife of several years temporarily left him, Fuller was headed down the fast lane for the ``good life,'' as he then saw it. He brought the Midas touch to every business venture he undertook and became a millionaire shortly after his 29th birthday.
With farms, cattle, stocks and bonds, and a very fertile business sense, it seemed only a matter of time before he multiplied his wealth many-fold. Then his wife, Linda, left, charging that in his pursuit of wealth, their marriage had become meaningless.
In fact, Fuller couldn't bear the thought of losing her. If money had come between them, he would get rid of it.
The transformation was as complete as it was dramatic. Literally obeying the biblical command to sell all and give to the poor, Fuller divested himself of his properties and gave his millions to charity.
Today the Fullers and their children live in a modest home in Americus, Ga., on the dividing line between the poor and more affluent areas of town. His salary as director of the organization he founded is less than $15,000 a year; his wife's earnings are less than $4,000. Fuller's legal practice, severely limited because of his commitment to Habitat, is variable and seldom exceeds $30,000 a year. By the standards of his profession as a trial lawyer, his earnings are minimal. With four children to educate, the family's income is modest by American standards. But ``we have been enriched in ways we never thought of,'' Fuller says.
In his search for a practical way to express his beliefs and feelings, Fuller looked into housing. ``Long ago we made a social, religious, and political commitment in this country that starvation is unacceptable,'' he says, ``but we have not yet said it is unacceptable for our citizens to live in subhuman conditions.''
Fuller refuses to acknowledge that Habitat's aim of eliminating shacks and slum housing from around the world is impossible. What has been accomplished in the first 11 years - 3,000 homes in 18 countries without a penny in government funding - ``would have been termed impossible when we began Habitat,'' he contends. The solution, he says, is ``to make it a matter of conscience everywhere that poverty housing is unacceptable.''
From a modest start of a few houses a year in 1976, Habitat has grown to where it builds three houses a day at present. It expects to make that six a day within the next two years, says Fuller. By 1996, he expects Habitat will be operating in 2,000 US cities and in 60 countries overseas.
A major impetus to Habitat's growth came when former President Jimmy Carter became committed to the organization in 1984. He serves on Habitat's board of directors and lends his name and his presence to its promotional campaigns.
He also brings practical experience as a carpenter to actual building projects for at least one week each year. The former President was on hand in Charlotte to take a hand in the project.
President Carter was drawn to Habitat because ``it's not a handout; it's a partnership.'' In a 1985 address on the subject, he described Habitat this way: ``It's not somebody up here helping somebody down there. It's somebody reaching out a hand and saying, `Let's work together.' And the family that is helped has a new experience, a great challenge.... In the process not only do they learn how to pour concrete, lay bricks, build roof trusses and walls, and fix up the grounds around the house as well, but they also feel that they have accomplished something on their own. They see what partnership can do.''
Robert and Jeanesther Murphy confirm Mr. Carter's comments. They moved into their Habitat home in Charlotte a little over a year ago. Today the lawns and flower beds are worthy of display in any home-and-garden magazine. The pride of home ownership is obvious, both inside and out.
``Me and my son helped pour the concrete on this house, and we helped build the walls, the roof, the insulation, everything,'' says Mr. Murphy, who works as a security officer. ``There's nothing that can go wrong in this house that I can't fix.''
The roaches, the rats, and the squalor of their former tenement are no longer an everyday fact of life for the Murphys.
The children's grades have gone up in school, and, says Mrs. Murphy of their youngest child, ``she doesn't wake up crying in the morning anymore.''