American Enterpise Group National Headquarters

American Enterprise Group National Headquarters DES MOINES, IA

ABOUT BNIM BNIM is an innovative leader in designing high performance environments. BNIM’s instrumental development of the USGBC, LEED, and the Living Building concept, combined with projects, methods, and research, shaped the direction of the sustainable movement. Through this involvement, the firm has redefined design excellence to elevate human experience together with aesthetics and building performance. In practice, this multifaceted approach to design excellence has yielded national acclaim, including the AIA National Architecture Firm Award, and consistent design recognition nationally and internationally. BNIM is Building Positive, a notion that describes how our practice leverages its collective capacity for design thinking to solve issues at every scale in a way that is focused on building the positive attributes of community and the built environment. Through an integrated process of collaborative discovery, BNIM creates transformative, living designs that lead to vital and healthy organizations and communities.

American Enterprise Group National Headquarters DES MOINES, IA

INTRODUCTION The American Republic Insurance building, home to American Enterprise Group (AEG), stands as likely the first concrete and glass modernistic corporate office building constructed in Des Moines, and nationally as one of the early Skidmore, Owings and Merrill (SOM) architect Gordon Bunshaft corporate concrete and glass commissions. SOM has been recognized as the leading corporate architectural design firm of the post-World War II era. The building’s associations with SOM further elevate its significance.

The building’s structural elements also serve as the main architectural elements, which flow from exterior to interior. Some of the design innovations include an upperstory tower supported on steel hinges that appears to float over a light-filled second-story; 90-foot prestressed precast reinforced concrete ‘T’ beams that are expressed on the tower’s exterior and interior; solid east and west concrete walls with recessed tinted window walls on the north and south elevations to reduce glare and air conditioning loads while providing ample natural light within the large workspaces.

Preserving the significant architectural and cultural characteristics of the building was of utmost importance during the renovation. BNIM approached the renovation with the intent that its work would be nearly impossible to detect. The effort has been referred to as an “invisible rehabilitation,” a testament to the consideration given to the building’s defining features.

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PROJECT HISTORY

Connecticut General Life Insurance Building

Gordon Bunshaft

Watson Powell Jr., then-Chairman and President of American Republic Insurance Company, was inspired by a 1962 visit to the Air Force Academy Chapel, designed

by SOM. Powell contacted SOM shortly thereafter and modeled the vision for his company’s new headquarters on another SOM design, the Connecticut General Life Insurance Building from 1957.

Intrigued by the Connecticut General design, Powell reached out to SOM. Watson Powell Jr., then the CEO of American Republic Insurance, recounted in a 1999 oral history video his introduction to SOM, “Knowing little about architecture, no, knowing practically nothing about the subject, I called the firm in New York... I initially asked [Bill Brown] to send me a sample standard of plans along with design details we could consider for our more than 400 people.” Bunshaft, a renowned modernist and partner at SOM, had other plans, integrating the insurance company’s needs with a new approach to workplace design.

In an 1989 oral history interview with the Art Institute of Chicago, Bunshaft spoke of his shift from “precision buildings like Lever or Chase or Pepsi-Cola …. and Connecticut General” to working with concrete, including the early corporate headquarters building for American Republic Insurance Company. He expressed his desire for a building that could float in its airiness and provide flexibility with its wide offerings of uninterrupted space. These concepts could be achieved with concrete mushroom or tree columns that also easily integrate technology and mechanical systems.

“We hope the building’s massiveness and strength will symbolize the security and strength of the company. But the design was arrived at more for its function than its appearance. The column-less areas inside the building allow us to arrange our work force efficiently…”

Watson Powell Jr. Speaking at the Dedication Ceremony

Bunshaft’s design represented the lean clarity of American workplace design in the modern era, incorporating mechanical and structural technology into the architectural expression of the building in a fully integrated manner. Advanced for its time, the minimal internal structure provides unobstructed views via ninety-foot clearspan.

When the building first opened, more than 10,000 people came to see it within the first year. More than 50 years after its completion, the AEG building continues to represent mid-century modern architecture and set new standards for workplace design.

Installation of Alexander Calder’s 1964 sculpture “Spunk of the Monk”

Original Computer Room (1966)

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SITE PLAN

8TH STREET

CENTER STREET

3RD STREET

4TH STREET

5TH AVENUE

7TH STREET

6TH AVENUE

PARK STREET

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8th Floor Lobby - Original condition (1966)

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ART AT AEG

“Our working lives are spent in an environment of beauty. And the art that surrounds us helps teach us that it is the individual, not the establishment, this is of primary importance.

While for efficiency we must be mechanized, computerized, and automated in the corporate world in which we live, we are constantly reminded [by the art] of the necessity to first regard human values.�

Watson Powell Jr. Collection of American Republic Insurance Company catalogue

8th Floor Lobby - Rehabilitated

DESIGN APPROACH ADAPTIVE REUSE V. REHABILITATION

“it is not right … that we should waste our energy, our health and our courage because of a bad tool; it must be thrown away and replaced.”

Le Corbusier excerpt from Towards a New Architecture, 1931

Historic preservation of modernist architecture seems inherently contradictory. After all, the progressive and unsentimental underpinnings of modernism would rather replace historic building shells than fill them with contemporary uses and turn them into mere facades - “bad tools,” as Le Corbusier argues. Adaptive reuse is appropriate for historic buildings with structural integrity that still retain urban, cultural and symbolic values but can no longer serve their original purpose. However, significant and critically recognized instances of modern architecture are deserving of a rehabilitation that goes beyond simply introducing reuse and physical renovation, additionally reinstating their original spirit.

The decision to rehabilitate the American Enterprise Headquarters building was based on a number of reasons: • Owner’s interest in preserving the building and pursuing Federal and State Historical tax credits • The significance of SOM and Gordon Bunshaft in the advancement of architecture and Modernist Buildings • The advancements in office buildings presented in the structure: • 90 feet clearspan office space • Integration of air distribution, lighting and acoustical treatment in the ductwork system

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“There are still plenty of good buildings lost, and plenty more that are renovated and altered out of all resemblance to their original condition.

But there is also a greater willingness than ever before to get to the essence of a work of architecture and try to bring out once again the qualities it had when it was new.�

Paul Goldberger American Architectural Critic and Educator

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DEFINING CHARACTERISTICS • Recessed window walls with warm gray solar bronze-tinted glass • Building systems integrated within exposed precast concrete “T” ceiling structure • Freestanding reinforced central core and uninterrupted clear span • Exquisitely detailed executive suites with custom furniture

Original Computer Room (above); Lobby (below) - 1966

BUILDING FLOOR PLANS The following floor plans illustrate the original design (1965), existing conditions (2014) and the innovative rehabilitations (2015) that increase workplace performance and life-safety while preserving the original design intent.

1965

2014

2015

ENTRY LEVEL provided an entrance courtyard, lobby, minimal private offices and large computer room with support space.

1965

2014

LEVEL 2 provided a dining area served by the lower level kitchen, lounge and an exterior deck

2015

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2015

LEVELS 3 - 7 provided enclosed offices and conferencing areas adjacent to the center building core and open flexible work space to accommodate large expanses of desks.

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2014

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LEVELS 8 provided leadership offices, administrative support and conference rooms. The mechanical system for Levels 2-8 are located on Level 8. Vertical ductwork is distributed through a continuous cavity along the east and west walls to serve the exposed perforated ductwork. The Entrance, Lower Level, and part of Level 2 were served by a mechanical room in the north half of the Lower Level

BUILDING SECTION LOOKING NORTH

BUILDING SECTION LOOKING EAST

BUILDING SYSTEMS Prior to the renovation, the mostly original, existing building systems were extremely problematic, often resulting in the experience of “all four seasons in one day.� The building also needed critical life-safety upgrades to bring it into compliance with modern code.

Replacing these systems with modern, energy efficient systems required substantial demolition of interior walls and finishes, including the exquisitely detailed executive suites. The mechanical systems for Levels 2 through 8 are located on the eighth floor, and vertical ductwork is distributed through a continuous cavity along the east and west walls to serve the exposed perforated ductwork. The east and west interior concrete masonry unit walls were completely removed on Levels 3 through 8. A significant amount of the concrete masonry unit walls and finishes enclosing the mechanical rooms on Level 8 was also removed. Following the major demolition of the building to accommodate these new systems, the walls and finishes were meticulously reconstructed.

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DEMOLITION STRATEGY

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Entry Level Demolition Diagram

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integrated ductwork removal bathroom reconfiguration wall demolition and rehabilitation

Levels 3-7 Demolition Diagram

KEY INNOVATIONS

1965 MULLION

2014 MULLION Replacement of glazing system on Level 3 - 8 with a custom frame to match the dimensions and finish of the original aluminum system and glass color that incorporated a thermal break frame and accommodated insulated glass.

MOCK-UP OF NEW GLAZING SYSTEM

1965 GUARDRAIL

2014 GUARDRAIL Modifications included the removal of the existing hedge and installation of a new guardrail to comply with current building codes.

SIGHTLINES

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DIFFUSER SUPPLY/INTAKE: CONTINUOUS PERFORATED OUTER JACKET, INSULATION GAP WITH VARIABLE AIRFLOW THROUGH BOTTOM SUPPORT BRACKET

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BNIM

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BNIM Architects

Architect

Design Engineers

MEP

317 6th Avenue Suite 100 Des Moines, Iowa 50309 p.515.974.6462 f.816.783.1501

8801 Prairie View Lane SW Suite 200 Cedar Rapids, Iowa 52404 p.319.841.1944 f.319.841.1949

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Charles Saul Engineering

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Structural

4308 University Avenue Des Moines, Iowa 50311 p.515.279.3900 f.515.279.5233

Snyder & Associates 2424 SW Snyder Boulevard PO Box 1159 Ankeny, Iowa 50023 p.515.964.2020 f.515.974.7938

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Key Plan

AMERICAN ENTERPRISE GROUP Civil

Des Moines, IA Project No: 14019.00

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Rev. # 1

Description Revision 1

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Date Issued Date 1

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Rev. # 1

Description Revision 1

Date Issued Date 1

REDESIGNED INTEGRATED DUCT SYSTEM

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Round perforated ductwork originally designed to provide supply and return air, acoustical treatment and a support to conceal the original fluorescent light fixtures. The redesigned duct system integrates modern versions of those essential components while including systems for current information technology and a life-safety system (conduits for telecom, integrated fire detection and sprinkler system are seen below).

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Design Development

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TYPICAL DUCT/JOIST CONCEPT DETAILS

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Copyright Š 2009 BNIM Architects

Existing duct section sightlines

Proposed duct section sightlines

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BEAUTY A majority of the original furnishings were selected or custom designed by Bunshaft and SOM. A number of these pieces, including custom desks, were restored and continue to be used in harmony with new, open office workstations selected and designed by BNIM that preserve access to daylight and views and provide modern workplace amenities. The new workstations address human health and evolving workplace standards, giving employees the flexibility to stand or sit while they work as desired.

In keeping with the original minimal design, BNIM incorporated custom sliding glass door office enclosures in the position of the original offices.

The original building meshed together workplace and AEG’s impressive art collection, the collection of which was initiated with the design of the building — a museum within an office.

The renovated space keeps the art as an integrated part of the experience. BNIM collaborated with AEG on providing new wall surfaces and substrates for the reinstallation of the art.

Construction (2015)

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Reinstallation of modified ductwork

The precast concrete “T� and cast-in-place coffered floor structure is exposed and is one of the defining characteristics of the building. The building heating, ventilating, air conditioning and lighting systems complete the typical ceiling structure and architectural expression creating a glowing series of coffers of light.

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Before the renovation, the AEG building was consuming

171

kBtu/sf/year and had 2 thermostats controlling the entire system

Following the renovation, the project is modeled to operate on

59.2

kBtu/sf/year, representing a landfill

65%

energy savings projected annual savings of $100,000

Almost

230

thermostats now control the building’s systems, giving each quadrant on each floor the ability to change temperatures

Existing conditions (2014)

The renovation allows AEG to retain its current

330

employees and gives the company space to grow for the next 50 years

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154,000 SF Completion in 2015 LEED Gold Certified

The revitalization of the American Enterprise Group (AEG) National Headquarters is an “invisible rehabilitation.” Since the building was completed in 1965, the owner had consciously respected its defining characteristics. However, over the next 50 years of occupancy, a number of its finishes and materials deteriorated, and its building systems were outdated and problematic. BNIM completed a complex renovation of the concrete structure while maintaining the building’s original integrity. The original concepts and characteristics that distinguished the building were preserved and augmented with energy efficient systems. Replacing these systems required substantial demolition of walls and finishes, including the exquisitely detailed executive suites, which were then meticulously reconstructed. Following the renovation, AEG’s art collection remains an integral part of the experience.

SELECT AWARDS 2017 MODERNISM IN AMERICA, CITATION AWARD Docomomo US 2017 THE AMERICAN ARCHITECTURE AWARD The Chicago Athenaeum: Museum of Architecture & Design & The European Centre for Architecture Art The American Architecture Award 2016 GOOD DESIGN IS GOOD BUSINESS Architectural Record 2016 HONOR AWARD American Institute of Architects (AIA) 2016 HONOR AWARD, EXCELLENCE IN ARCHITECTURE AIA Kansas 2017 MERIT AWARD, EXCELLENCE IN DESIGN AIA Iowa 2015 HONOR AWARD AIA Kansas City 2015 HONOR AWARD, HISTORIC PRESERVATION OR ADAPTIVE REUSE AIA Central States Region

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2460 PERSHING RD SUITE 100 KANSAS CITY MO 64108

317 6TH AVE SUITE 100 DES MOINES IA 50309

797 J ST

816 783 1500

515 974 6462

619 795 9920

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