Rockefeller had more of it. Mellon did more with it. Barnes had more interesting ideas about it. But in the annals of great early 20th-century art collectors, no other plutocratic culture vulture quite measures up to Henry Clay Frick—not, at least, when it came to an eye for the good stuff. When the Pennsylvanian coal baron moved into a spacious, Thomas Hastings–designed mansion on Fifth Avenue in 1914, he brought with him an already substantial trove of paintings, which he continued to augment it right up to his death, five years later at the age of 69. He didn’t bother with such trivial distinctions as movements or styles; he didn’t even organize the work by theme or by era. He just bought solid-gold masterpieces, over and over, and put them wherever he felt they looked best. And then, after he was gone, he invited the world to come have a look. Updates include new lighting, additional seating, and more provisions for accessibility. (Nicholas Venezia) After a prolonged separation, Frick’s house and his masterpieces—1,800 of them, in total—have at last been reunited and are once again viewable to the public as the old man intended. Nearly five years in the making (and accompanied by no small amount of controversy, not the least over a since-scrapped proposal to demolish its eastern garden), the renovation of the Frick Collection by Selldorf Architects with Beyer Blinder Belle (BBB) has added more space for art, curators, and for people, bumping the size of the venerable campus by fully 10 percent to 196,000 square feet. And, as of April 17, it is now reopened to the public. For the first time, museumgoers can ascend the staircase to see additional rooms on the second level. (Joseph Coscia Jr.) Upstairs quarters of the Frick family—previously office space—were restored and now house galleries. (Joseph Coscia Jr.) For museumgoers already familiar with the beloved institution, what awaits them is something astonishing: Like the common recurring dream of discovering a heretofore-unknown room in one’s apartment, the building has undergone a kind of magical, dimensional mitosis, growing on the inside while appearing to remain largely the same from the street. Changes have not stripped the museum of its historic character, as seen in the West Gallery. (Joseph Coscia Jr.) Skilled plaster workers, woodworkers, and other craftsmen played a major role in the renovation effort. (Joseph Coscia Jr.) For those who have never been before, the revelation will be hardly less remarkable. The Frick—“the world’s favorite museum,” as its (obviously biased) director Axel Rüger called it during a preview event—has always been New York’s great offbeat cabinet of curiosities; it is the only thing that comes close to the kind of small, exquisitely curated musée des beaux arts one often finds in second-tier European cities. (New York’s Hispanic Society Museum is a close second; incidentally, it is also being renovated by Selldorf and BBB.) Walkable in an hour or two, the works on display from Velazquez, Rembrandt, Whistler, Turner, and Titian also reward a whole day’s worth of contemplation, a process to which the refurbished environment is especially conducive. Selldorf’s rework is the result of many hands, including a small army of skilled plaster workers, woodworkers, and other craftsmen who, in coordination with BBB, “supported us, led us, goaded us along the way,” as Selldorf put it. The updates include new lighting, in particular above the celebrated long gallery; additional seating in the upstairs galleries; an actual cafe; more and better bathrooms; more provisions for accessibility; an auditorium, maybe Selldorf’s finest moment here, an almost Joseph Urban–ish flourish whose clamshell twist combines art deco showiness with pristine acoustics by Arup. No one arriving for the first time would guess just how peculiarly incommodious, if sometimes charmingly so, the museum used to be. Frescoes remain a highlight of the museum and art-viewing experience. (Joseph Coscia Jr.) More astonishing is that all these changes have in no way stripped the house of its character. On the contrary: Admirers now have access to even more of the original interior, with the upstairs quarters of the Frick family—previously reserved as office space—restored and made an integral part of the exhibition experience. Now, for the first time, explorers can ascend the staircase to see additional rooms repurposed as cozy galleries. From the lavish baroque frescoes in the old nursery to the new vitrines with decorative pieces seldom exhibited in the past, the warren of former boudoirs and studies doubles down on the peculiarly intimate, privileged art-viewing experience that has always set the museum apart. Looking out to Central Park over the parterre (also recently restored), surrounded by exquisite wall treatments (same), museumgoers can escape into a complete, Gilded Age fantasy. The reception hall staircase is new, but was designed to seamlessly integrate with the historic interiors. (Nicholas Venezia) Of course, it’s a fever dream made possible by complex technical choreography. The $220 million project includes substantial new construction, cleverly concealed within the existing complex and hosting a suite of conservation studios, offices, an education space, and a new gift shop. (ADA access, including at the main entrance, was also included.) A new back-of-house corridor links the library reading room to the museum with its own internal connection to the much-improved main lobby; previously the journey required a hike around the block. Above, within the new tower—clad in Indiana limestone that perfectly mimics the historic facade—staffers can see how this surgery was carried out, including where an exposed steel beam sticks out somewhat awkwardly in front of a service elevator. Yet for the average visitor, movement between the historic home and the new spaces is so seamless as to make it almost impossible to tell where, exactly, one is in the overall scheme, at least without a 3D, color-coded sectional drawing to clarify where the old portion ends and the new one begins. (Full disclosure: I have seen such a drawing. It is still almost impossible.) Selldorf has even taken care to give the new lobby its own staircase, less grandiose certainly than its pendant in the mansion proper, but nonetheless charged with a distinctly prewar glamour, as through parasol-clutching, cloche-hatted dames were about to come swanning down it. The auditorium at The Frick (Nicholas Venezia) A suite of conservation studios, offices, an education space, and a new gift shop were also part of the renovation. (Nicholas Venezia) All these infrastructural gymnastics were necessary to make way for the new galleries upstairs, and, more broadly, to support and expand the Frick’s overall mission. Along the way, they have also yielded a museum which furnishes more than ever a mysterious synchrony of environment and art. Now back in his proper venue, Bronzino’s lad with his absurd codpiece glowers beside the staircase, daring visitors to ascend where the velvet rope used to hang, while Ingres’s coquettish young woman presides over one of the bedrooms, head inquisitively cocked. Holbein’s Cromwell and Moore flank the mantle as before, looking somehow still more comfortable in their luxurious enmity, and even the faces on the coins now showing in one of Frick’s former studies seem glad to be out of storage. It was fun, of course, to see some of these same works installed at the Frick Madison, the pop-up within Marcel Breuer’s building for the Whitney Museum of American Art where they were temporarily billetted and where they took on a new and novel sort of life. But honestly, after so much, it’s great to have the gang back together. Ian Volner has contributed articles on architecture and design to The New York Times, The Wall Street Journal, and Architectural Record, among other publications. He is the author of numerous books and monographs, most recently Droese Raney X Design.