Especially now, and especially in New York, architecture is a game played by men — and occasionally by women — of a certain age. It may be that some architects have received major commissions in New York before they hit 40, but not in this century and probably not in the last one. Though there is nothing inherently gerontocratic about the art of architecture, there is nothing especially meritocratic about it either. That is why most of the plum assignments in New York are farmed out to those who have conspicuously paid their dues, something that few people under the age of 50 have lived long enough to do. And so it is that for architects, if for no one else, life begins around 60.

Juergen Riehm and David Piscuskas, the principals of 1100 Architect, have not yet reached that milestone, but they are nearly there. In several dozen projects, they have already done their sober and responsible best to enhance the architectural fabric of Manhattan. A sumptuous new book from the Monacelli Press, with an essay by Donald Albrecht, pays tribute to their achievement and is doubtless intended to propel them to the next level of renown.

This downtown firm is more modest than most. Its vocabulary is that of mid-century modernism, even though its use of it is informed in every beam and strip-window by that deeper sense of experiential richness, as opposed to pure visual form, that distinguishes the neo-modernism of the present time from its antecedent of 50 years past.

One of the facts of life for a relatively young Manhattan-based firm like 1100 Architect, which was founded in 1983, is that most of its projects to date have consisted in reconfiguring the interiors of pre-existent structures. These have included townhouses, duplexes, SoHo boutiques, as well as the two MoMA design stores.

Given MoMA’s status as the arbiter of design, the latter two assignments are especially important. The Modern’s aesthetic, despite all the architectural vicissitudes of recent years, has always been one of unquestioned fealty to the international style. In its galleries, as in its shops, you find all manner of modern and postmodern exorbitancies. But the scrupulously white and geometric contexts in which they are set afford a consoling sense of order and control: Everything that shows up at MoMA is instantly sucked into the etherous abstraction of modern architectural history.

MoMA undoubtedly chose 1100 Architect because the firm sympathized fully with that institutional attitude and the aesthetic it accompanies. And although the uptown store, on 57th Street, is conspicuous for undulating white walls in the manner of Alvar Aalto, the SoHo location is more typical of 1100 Architect in its strict use of uninflected lines. The latter project also afforded the architects more room to create, since it exists on two levels joined by a natty stairway of spare terrazzo steps and minimalist steel railings. Though the store’s design does allow for wooden floors and for not quite modernist bare brick, the rest of its vocabulary is almost textbook modernism, from its white walls and white illuminated ceilings, to its tasteful accents in transparent and translucent glass.

A similar aesthetic governs one of the firms more ambitious projects. Recently completed, it is an entirely new residential structure on the Upper East Side that is also one of the most unapologetically neo-modernist projects in the city (and there are hundreds of them by now). This four-story building at 117 E. 80th St. extends to the width of two townhouses and seems almost incongruous amid the genteel columns, pediments, and friezes of the neighboring structures. And yet, paradoxically, it is every bit as historicist as they, even if it looks back 50 years rather than 500. You see this in the Gropius-inspired ribbon windows on the second floor, in the sheer, unadorned Wisconsin limestone that surrounds the windows on the 3rd and 4th floors, recalling Adolf Loos and LeCorbusier, and in the resin-stained mahogany of its broad doorway.

Admittedly, a very different feeling governs 1100 Architect’s highly accomplished reinvention of the Little Red Schoolhouse and Elizabeth Irwin High School, a famously progressive institution at 272 Sixth Ave. This consists of a renovated townhouse as well as a new and larger structure on its southern flank. Although the interior has a few of those undulating surfaces that cry out progressive (as of 1935, at any rate) and although the façade shows some graceful brickwork, the insistent rectalinearity of the building and the ribbon windows on the first and third floors reassert the firm’s neo-modernist credentials.

It is too early to comment on what promises to be their most ambitious project to date, a 13-story residential tower at 241 W. 19th St. Accordingly to the rendering published in the Monacelli Press’s new monograph, this building’s emphatic use of blue accents around its curtain wall façade looks to be an energetic departure from what the firm has designed thus far.

Surely it is more dramatic than what has gone before, but is it dramatic enough? Reviewing the projects listed in this new book, one wonders if it is possible to be too responsible, too decorous in one’s application of neo-modernism. And then there is the collateral issue of whether that neo-modernism, enshrined in the work not only of 1100 Architect, but of a hundred other well-intentioned firms in Manhattan, has not played itself out by now. Having evolved as a rebuttal to the historicism of the 1980s and as an alternative to the deconstructivism and blob architecture of more recent years, it has settled into the comfortable status of a pleasing default style. It is the idiom that architects throughout the world have begun to use when they don’t want to think too much. Before long, we may need to be roused, once more, by some heartier fare.