NEW YORK—Donald Judd was already complaining in 1974 that Soho was finished as an artists’ quarter. He was premature in his judgment, but I’m sure he would approve of the fact that, right at the heart of the tourist-shopping hell that the neighborhood has become, his own former home and studio at 101 Spring St. is once again a destination for folks with a serious interest in art.

In the last month, the Judd Foundation has begun offering public tours of the building. Currently they only happen on a Friday morning and are limited to eight people per tour, but I predict that once the word is out, the place will be swamped with visitors. And they won’t be disappointed.

Anyone who knows Soho knows the Judd building. It’s the rather dilapidated—and currently scaffolded—cast-iron building on the corner of Spring and Mercer, with the bare studio space on the ground floor. It turns out it is the last single-occupancy cast-iron building in the whole of Soho, and it certainly must have the last storefront for blocks that is not housing a hip boutique, bar or coffee shop.

Judd bought the building in 1968 for less than $70,000. It was the first property he owned (though, of course, he eventually bought up huge tracts in Marfa, Texas) and he set about turning it into a home for himself and his family, as well as a studio space and—perhaps most significantly—a place to evolve his ideas for the permanent installation of his own work, and that of his contemporaries.

Now that the Judd Foundation is letting people in—even though the place is still in the throes of a large-scale renovation—it provides a rare glimpse into the life and art of one of America’s most singular artists. It is a fascinating experience.

Everything remains just as it stood at the time of the artist’s death in 1994. In the kitchen, cutlery is laid out along a shelf with all of the exactness of the worst OCD sufferer. The adolescent bedrooms for his children, Flavin and Rainer, are decorated with a Claes Oldenburg drawing of Mickey Mouse and a tiny Kurt Schwitters. And in the formal dining room—which was apparently hardly used—a wonderful, huge Frank Stella is hung so precisely that you would assume it was made to measure (though, in fact, it wasn’t).

There’s a degree of ghoulish fascination involved in visiting the house. Aside from those knives and forks, there’s a half-empty honey jar on the kitchen counter and half-full liquor bottles on the shelves.

And there are other surprises, as well. It doesn’t seem odd to find a beautiful 1954 Ad Reinhardt here, but an Oldenburg “Store” relief of sausages? Or a spiky Lucas Samaras box by the side of the bed?

The tour costs $30, or $15 for students, seniors and artists. (Intriguingly, proving yourself an artist is subject to a test to be determined by your intern-guides.) Currently, most visitors appear to be either art museum folks or students.

On the morning I visited 101 Spring, my companions were a group of Bard College curatorial students and an Englishman who explained that no, he wasn’t an artist, but he’d always been fascinated by Judd.

The guides themselves are still new to their jobs. They get the odd fact wrong here and there, and mine seemed a little thrown by one or two of the questions, but their palpable enthusiasm for the place more than outweighs any shortcomings. They talk about Judd in the present tense and are genuinely interested in new insights that visitors might bring.

As for the house, there are inevitable plans for further refurbishments and safety improvements (currently you have to sign a slightly unnerving liability release), but no matter how carefully these are done, the building’s time-capsule character is bound to suffer.

Presently 101 Spring still enjoys a “secret New York” status, so my recommendation would be to see this place as soon as you can.