Lewitt designed the work specifically for the wall where it originally appeared. But that wall was destroyed, and there is no other wall like it.
In Lewitt's work, the art is the idea, expressed in a drawing and a title provided by the artist. "The idea is the machine that makes the art," Lewitt famously wrote in his Sentences on Conceptual Art.
Therefore, when SAM acquired the wall drawing, it received Lewitt's instructions, not a wall drawing itself—which is why it the first version could be destroyed, and which is why another version can be made now. This is not a replica or a re-creation. Lewitt's paintings are executed by teams, and each one is a new work of art born of the same idea.
At the same time, there is precision involved, and the original idea remains. But since there is no similar wall, and since the dimensions of the original were based on the wall, how does a team enact a whole new performance of Wall Drawing 881, Seven Cubes with Color Ink Washes Superimposed? I'll explain soon, or ask them yourself.
This is what it looked like yesterday.
Half of the crew at work. They're supervised by a representative from Lewitt's estate who flew out to oversee the process.