It is peculiar that the most popular study space at Yale — a university so revered for its architecture — is a basement.

The two underground levels of Bass Library, however, are sumptuously decorated, equaling in material beauty the interiors of Yale’s other recently renovated buildings. The space — I hesitate to call it a building — is certainly better appointed than the Cross Campus Library it replaced, which had become a ragtag collection of decaying sofas and leaking roofs by the time it was closed last year.

Even so, the wood-varnished Bass is lacking both in architectural creativity and consistency. In execution, it solves some of the mistakes of the old CCL but also creates some new ones.

The bacchanal last month with which students greeted the opening of Bass demonstrated the desire among students for a central gathering place for study and socializing. And if Bass does anything well, it is in providing that space in the library cafe.

The cafe’s design is masterful, and one of the few places where the work of Hammond Beeby Rupert Ainge — the architecture firm that directed the renovation — really shines. With vaulted ceilings and light-colored materials, the room feels open and airy, as if it were open to the sky rather than submerged two dozen feet under the ground. Circulation and seating areas intersect as they should in an environment meant for conversation.

However, the library itself — behind large glass panels that physically separate it from the cafe but allow for a visual connection — is a study in poor use of space. Just like in the cafe, circulation and seating are intermingled; to get from one end of the library to the other, one must pass through many of the study areas. The library poorly separates public spaces, such as the passageways and internal stairwells, from the relatively private areas necessary for studiers, especially for those who do not choose to lock themselves into the weenie bins. Sitting quietly and concentrating on work becomes more complicated because of the constant distractions caused by people who are simply trying to make their way through the space. This was not a difficulty in the old CCL, where the large study tables were located away from the main paths of circulation and were therefore more useful.

Exacerbating the problem are the library’s ceilings. The cafe takes advantage of vaults to increase the perception of openness, and so does the library, except it only has the curved ceilings over the stacks! Thus, the benefit of heightening the ceilings perceptually is — irrationally — only available to those hunched over searching for books, rather than for the majority studying at the tables.

Though the pathways from the Sterling end of the library to the cafe are well placed, the internal stairwell connecting the two basement levels is not. Instead of inviting users from one floor to the next, it draws them down menacingly into a pit and then forces them to turn around to get to their final destination, much like the stair in the center of Sterling’s lobby once did. With a little tweaking, the stairway could have been moved to a more appropriate location.

The architects chose wisely, however, to remove the staircase that led from the great vault of Sterling into the plebian cellars of Machine City, because it was disruptive to the sense of spaciousness that Sterling’s cathedral-like nave was meant to convey. The new set of spiraling steps off to the side of the nave both opens up the interior of Sterling and makes the passage below ground less intrusive and more intuitive than it once was.

But having descended into the reading room that replaced Machine City, the path to the rest of the library is not clear. Not only does the stair empty out across from a wall less than twenty feet away but the room is cluttered with tables and chairs; it is certainly not a distinguished entry. Blocking the tunnel to the stacks is a pair of giant columns that make the trip difficult to navigate. And then there’s the tunnel itself: It has always been claustrophobic — too long, too low, too bright — and it was unimproved by the renovation, which merely added brick walls.

That said, Bass Library succeeds in bringing a sense of natural light into its depths. The openness of the study areas and the resulting integration of circulation and seating may produce difficulties for serious students; convenience is sacrificed for the sake of making this space feel more outdoors than any other interior at Yale, with the notable exception of the Music Library.

The architects were careful in carving out the double-height group study rooms, creating full glass windows into the library on both the first and second basement levels. Their walls are brick, giving them the impression of exterior space and differentiating them from other spaces in library. The weenie bins are similarly glass-sheathed and provide students hell-bent on utter isolation appropriate surroundings.

Bass Library’s decor is an ambivalent mix of Gothic, Victorian, art deco, modern and post-modern, but it attempts a sense of unity. Yale has for centuries played the game of duplication and repetition of antediluvian ornament in its architecture; the original “modern” CCL was an exception to the rule. So just as Saybrook and Branford Colleges imitated Oxford buildings built centuries before and looked acceptable in New Haven, Bass Library’s historicism is within context.

But certain elements — like the painted tiles screaming “Lux et Veritas,” the Danish Charlottenborg lamps above the cafe, the Eames chairs in the second basement and the over-the-top Gothic entryway between Berkeley and Harkness Hall — go too far. As a result, the luxurious atmosphere of the library is overshadowed by the confused melange of themes.

Seemingly unable to make up their minds about how the library should appear, the architects cherry-picked references to styles centuries apart in origin. But these references do not befit one another and prevent the library from assuming a necessary stylistic consistency. Likewise, the library, while providing a valuable sense of openness, is unable to resolve the conflict between public and private space, resulting in less-than-maximized utility.