The convergence of shifting workplace norms, housing shortages in urban cores, and the urgency of embodied carbon reduction has reframed how architects, cities, and developers approach legacy office buildings.
In Chicago, the historic Leiter II Building at 401 S. State Street offers one of the clearest opportunities to explore this transformation.
This white paper presents the findings of a design study exploring how 401 S. State could become a model for thoughtful, technically grounded and sustainable urban reuse.
New Leiter Building II - 1891
First, Some History
Designed by William Le Baron Jenney and completed in 1891, the Leiter II Building stands as a landmark of early steel-frame construction and a defining work of Chicago School architecture. Jenney’s structural innovations allowed for unprecedented spans and flexibility, with a full metal frame supporting nine structural bays, 144-foot-deep floorplates, and nearly 16-foot ceilings. The granite-clad façade expresses this internal logic with clarity and restraint—continuous piers and subtle asymmetries create a rhythmic civic presence that spans an entire city block.
Its structural resilience and monumental scale offer rare adaptability in a downtown core increasingly shaped by educational and cultural infrastructure. With its return to the market, the question is no longer whether it can be reused, but how best to unlock its next chapter.
Strategic Location and Civic Momentum
401 S. State Street sits at a pivotal intersection of Chicago’s civic, cultural, academic, and transit infrastructure. Directly across from the Harold Washington Library and near several universities, the building is deeply embedded in the city’s architectural and institutional fabric. Once a pioneering department store, it now anchors a corridor transitioning into a mixed-use district shaped by education and urban renewal.
Transit access is exceptional, with CTA lines, bus routes, and Metra connections all within walking distance. This connectivity supports car-free living and links the site to the broader region. Nearby parks, including Grant Park and the evolving Harold Washington Library greenspace, offer valuable relief from the dense urban core.
The building is part of a living urban network. Its reuse offers the chance to support the city’s momentum, reinforce walkable density, and write a new chapter in Chicago’s story—rooted in preservation, reactivation, and purposeful reinvention.
Context Analysis
Design Potential: Rethinking the Unlikely
401 S. State Street was not chosen for this study because it is an obvious candidate for conversion. In fact, it represents a building type that is often overlooked in the adaptive reuse conversation: deep, wide, and low-slung structures with limited perimeter exposure and rigid structural grids. These buildings, common in mid-century downtown cores, are typically dismissed as too inflexible, too dark, or too costly to reconfigure. With the help of our colleagues at TY Lin we examined the building Architecturally and Structurally.
Yet they are also among the most numerous, and their embodied carbon and urban embeddedness make them critical to any serious discussion of sustainable transformation. Rather than treat its deep floorplate and repetitive structure as obstacles, we approached them as design opportunities.
This is precisely why we chose to study it.
Our study affirms that with careful intervention, even the least likely structures can become powerful contributors to the next generation of urban living. It is a call to think differently about reuse, not only as a technical solution but as a creative act that reframes the boundaries of possibility.
Two Strategies
1. Convert the building to Multifamily
This approach introduces a new structural parking plinth within the deep floorplate, strategically placed on floors two through four to meet market needs and support residential uses above. A courtyard is carved above the plinth to bring daylight into perimeter liner units and to create a rooftop amenity space. With less than one-third of the structure removed, the design qualifies as a renovation rather than new construction.
Above, one, two, and three bedroom units are organized for light, views, and efficient circulation. The restored historic façade reinforces the building’s civic presence along State Street.
2. Create A Student Life and Recreation Hub
This alternative strategy reimagines the building as a shared residential campus for multiple nearby universities. Within the deep floorplate, a full-campus recreation and fitness center anchors the building and becomes a shared amenity across institutions.
Above, compact four-bed micro-units allow for high-density student living, each with access to daylight and shared social spaces. The model reduces cost burdens on individual universities while leveraging the building’s size and location to create a truly collective campus experience.
Multifamily
Framed by structure, carved for light, connected to the city, grounded in history.
Design for a Deep Plate
Let’s be clear—buildings with deep floorplates like 401 S. State are rarely seen as ideal candidates for residential conversion. This study challenges that assumption. By inserting structured parking into the center of the building, the design puts program where daylight is not required, efficiently using space that would otherwise be difficult to occupy. Above that, a courtyard is strategically carved on the east side, reducing the overall depth and introducing light and air into a new perimeter of double-loaded corridor units. This move not only creates livable, well-proportioned homes, but also maintains the building’s historic facades in their entirety. The column grid informs the courtyard geometry and aligns with new circulation strategies, including added elevator cores and vertical access points. Together, these interventions suggest that even floorplates once considered too large or inflexible can be made adaptable—supporting vibrant, high-density residential life within a preserved architectural framework.
Parking
A courtyard is carved to allow light to penetrate the deep floorplate, utilizing existing structure
is added within existing column grid
Design for a Deep Plate
The residential section diagram illustrates a layered strategy that integrates parking on levels 2, 3, and 4 within the existing structure—an unconventional move that maximizes utility without expanding the footprint. Above, a central courtyard is carved into the upper floors to introduce natural light and create amenity space for the residents. This vertical composition reimagines the deep floorplate as an asset rather than a limitation.
The proposed planning strategy for 401 S. State embraces complexity as a driver of innovation. Rather than imposing a conventional residential layout, the design team developed a mix of one-, two-, and split-bedroom units that align naturally with the building’s existing column grid. This allows the structure to remain largely intact while achieving unit diversity and livability. New vertical circulation strategies, including the repositioning and addition of elevator cores, improve efficiency and future adaptability. At the ground level, the plan retains the
While the units extend deeper than typical multifamily prototypes, this depth is transformed into a strength. Interior dens, flex rooms, and thoughtfully scaled living areas take full advantage of the building’s width, offering spatial generosity and programmatic flexibility. The result is a high-efficiency layout that meets contemporary residential expectations without sacrificing architectural integrity or financial feasibility. It reflects a belief that planning is not just about fitting units within a box, but about shaping lives within a framework that already has a story to tell.
Liner units are configured in a conventional double-loaded corridor
Unit Examples
Example units work with existing column bays, to preserve efficiency in construction
TWO BEDROOM
TWO BEDROOM - SPLIT
ONE BEDROOM
By The Numbers
Student Life
Anchored by wellness, shaped for community, connected through learning, elevated by design.
Student Life as Urban Infrastructure
The Student Life scheme takes a bold approach by embedding a full recreation and fitness center at the core of the building, surrounded by compact, efficient student living. This is an uncommon solution in dense urban contexts, where space for large-scale athletic or wellness facilities is rarely available to universities. Combining that function with living is a natural fit.
At 401 S. State the existing depth and structure of the building align almost exactly with the footprint typically required for a modern campus rec center. Rather than fight the constraints of the floorplate, the design embraces them, placing high-demand communal amenities where daylight is limited and wrapping them with four-bed micro-units that prioritize efficiency, privacy, and proximity to shared resources.
The Second Floor allows for anchor tenants to have a second retail floor, perfect for a grocery or big-box style retailer.
The Ground Floor makes room for two major anchor tenants with convenient loading and back of house spaces.
Ground Floor
Second Floor
Urban recreation centers are rare but increasingly essential. Universities are recognizing the critical role that physical activity plays in student health, mental wellbeing, and social connection.
At 401 S. State, the wide and deep floorplate—typically seen as a barrier to reuse—becomes an advantage. The central floors of the building are perfectly suited for a full-scale athletic and wellness facility, including fitness areas, multipurpose rooms, and shared amenities. By locating these functions in the center of the plan, the design maximizes daylight for residential spaces at the perimeter while efficiently occupying areas that do not require natural light.
This strategic placement transforms a structural challenge into a communal asset, offering the kind of wellness infrastructure that few downtown campuses can provide. Shared across institutions, this facility can support a broader academic community while reinforcing the building’s civic role in the heart of the city.
Design for a Deep Plate
The residential section diagram illustrates a layered strategy that integrates parking on levels 2, 3, and 4 within the existing structure—an unconventional move that maximizes utility without expanding the footprint. Above, a central courtyard is carved into the upper floors to introduce natural light, create outdoor amenity space, and improve livability for the surrounding units. This vertical composition reimagines the deep floorplate as an asset rather than a limitation.
The proposed planning strategy for 401 S. State embraces complexity as a driver of innovation. Rather than imposing a conventional residential layout, the design team developed a mix of one-, two-, and split-bedroom units that align naturally with the building’s existing column grid. This allows the structure to remain largely intact while achieving unit diversity and livability. New vertical circulation strategies, including the repositioning and addition of elevator cores, improve efficiency and future adaptability. At the ground level, the plan retains the potential for large-format retail, including the scale needed to
The wellness terrace provides rare outdoor space for fitness and recreation in the center of the city. It introduces light and fresh air to the interior of the building and creates a communal hub that supports physical and mental wellbeing.
Student living floors are arranged with doubleloaded corridors for efficient circulation and compact four-bedroom suites. Each unit balances privacy with shared space and is designed to support community, study, and day-to-day comfort within a dense urban setting.
Level 6
The planning strategy was informed by both national student housing trends and localized needs across nearby institutions. In a setting where universities often lack the scale or budget to build these kinds of facilities independently, this shared model introduces a new kind of academic infrastructure: flexible, collaborative, and civic in nature. The result is more than just student housing. It is a complete, self-contained campus ecosystem made possible by an unlikely building type and a deeply site-specific design response.
By
The Numbers
Sustainability Through Preservation and Precision
At 401 S. State, sustainability begins with the decision not to demolish. By retaining the majority of the existing structure, the design preserves embodied carbon and avoids the material and energy costs of new construction.
Strategic surgical interventions—such as selective removal for daylight courtyards or rooftop terraces—allow the building to meet contemporary performance and livability standards without compromising its architectural integrity. The plan supports walkable, transit-oriented living in one of the most connected parts of Chicago, reducing dependence on cars and reinforcing sustainable urban patterns. Systems and envelope upgrades can be layered within the existing framework, improving operational efficiency while respecting the building’s historic character.
This approach aligns with Perkins&Will’s belief that the most sustainable buildings are often the ones already standing. Through adaptive reuse, 401 S. State becomes not only a place to live or learn, but a model for climate-conscious urban transformation.
From Structure to Story
401 S. State Street offers an opportunity to bring new purpose to a structurally innovative and historically significant building. This study reimagines what buildings like this can become—places filled with light, layered with community, and programmed for the way people live, learn, and connect today. The approach prioritizes design quality and sustainability, preserving embodied carbon while introducing new forms of civic and residential life. It responds to urgent urban needs: increased housing, shared student infrastructure, and a stronger connection between people and place.
Buildings like this exist in cities across the country, and many face an uncertain future. Reuse offers a path forward that is both climate-conscious and culturally grounded. Saving these structures is not just about preservation. It is about activating their potential to serve the evolving needs of our communities.
