When Sol LeWitt died in April last year, there was no debate over where or how his life and work should be celebrated. He had already decided that a permanent showcase of his vast geometric forms and schematic color arrangements should be put on permanent display at MASS MoCA, the complex of former brick textile factory buildings that has become the Berkshires’ magnet for those interested in Modern and Contemporary art.

“Sol came here and chose which buildings he wanted to use to house his art and he picked the heart of MASS MoCA,” the gallery’s director, Joe Thompson, said, as he led a group through a maze of cavernous rooms divided by 12-foot-high screens.

“We gave him a model of the space and he arranged and rearranged everything to the smallest detail, clearly signaling what should go where and exactly how each drawing should be executed,” he said.

LeWitt, with the cooperation of his wife Carol and his two daughters, and with funding for curatorial provision arranged by the director of Yale University Art Gallery, Jock Reynolds, gave 100 drawings for a permanent show expected to be on display for 25 years. It’s what Mr. Thompson calls “a 25-year netherworld.”

This legacy collection is currently being applied and erected by a small army of about 60 artists. The exhibit — which covers 30,000 square feet on three floors — is arranged in the chronological order of LeWitt’s inspiration, from the ground to the third floor.

A key part of Sol LeWitt’s method was to replicate his art at will and he gathered around him a staff of 20 artists who are the key to translating his instructions at MASS MoCA. In addition, since the project began on April 1, a dozen LeWitt apprentices have joined to learn the ropes, while in recent weeks, 30 fine art undergraduates from universities and art colleges have been drafted for 10-week internships to ensure that the gargantuan project is completed on time for its grand opening on November 16.

The artists begin with blank walls and, under close guidance from members of the LeWitt atelier, the paints or pencil marks are applied with strict precision, according to typed instructions left by the artist. While the directions are specific, they sometimes allow for some marginal discretion by the amanuensis.

For one piece, LeWitt merely demands that “an irregular horizontal line” be drawn in black across the top of a white wall. Then he dictates that further artists take it in turns to follow the line below in red, blue, and yellow. To achieve LeWitt’s desired effect, it is important that the lines be applied by different hands in random order to allow for haphazard variations. (An inattentive hand that drew a blue line out of order caused the project to halt temporarily for it to be covered with white paint.)

Similarly, a three-walled installation on bronze-painted wood pegboard demands that 1-inch rolled colored tissue paper be inserted at random into the holes. A notice on another incomplete artwork registers progress toward achieving LeWitt’s stated goal: “This wall has 2,750 lines so far.”

A piece which will eventually give the effect of a giant three-dimensional convex or concave tube is applied by three artists simultaneously, each brandishing a 2B pencil as they scribble at different levels of intensity, what they call “taking the line for a walk.” The doodlers admit that their hands and wrists are exhausted by the repetitive process and that they continue to scribble in their sleep. On a recent Saturday, they had been scrawling for seven days, with three more days of scribbling needed before completion.

To ensure the perfect intensity of color demanded by LeWitt from the layers of Swiss acrylic paint, the artists must apply exactly the prescribed number of coatings, sometimes with rollers, sometimes with sponges, with the time each layer is applied faithfully recorded in a log.

LeWitt insisted that the pieces should be seen at their best under the full glare of strip lighting, which will be somewhat muted in the upper galleries by the darkness of the maple wood floors.

The hive of industry and the smell of the paint have attracted flying insects that wreak damage on the fine lines and carefully tinted shapes that make up LeWitt’s work. A distressed assistant, tired of having to instantly restore the fresh paintwork, has pinned up an impromptu warning: “Attention bugs: No dying on the wall. Take your death elsewhere.”

Another sign is a warning to the visitors whom Mr. Thompson guides through the LeWitt labyrinth. “Do not touch this wall,” it warns, adding in brackets, “Or any other.”