April 2005

Transforming a historic caterpillar into a "Class A" butterfly

Babette Kis, A.I.A., Project Architect, and Venu J. Gupta, P.E., Superintendent, Buildings and Fleet Services, Department of Public Works, City of Milwaukee, Wisconsin

The Robert A. Anderson Water Tower and Municipal Building is a truly innovative "Class A" facility. The City of Milwaukee Buildings and Fleet Services asked Babette Kis, a staff architect, to develop a plan for the remodeling of the interior of the building. Kis met many construction challenges within a two-year remodeling span. This 1938-1939 art deco-style building, formerly an underused facility, is now a "Class A" office tower with state-of-the-art, highly-efficient heating, ventilating and air conditioning (HVAC) and other electromechanical systems.

Underutilized for many years, the historic former Town of Lake Water Tower was given new life as an energy-efficient office environment, and mechanical and electrical systems were replaced. This unique undertaking began in 2001 with a study of the original 1938 structure. At that time, it was determined that the 160-foot-tall building, which appeared to be of Type 1A or 1B fire-resistive construction, had been built as a two-story masonry unprotected building.

The height of the tower, 160 feet, offered opportunity for good transmission capability and now provides revenue to the City by letting private cellular companies install antennas. The City has also taken advantage of this height by installing a transmitter and antennas on the tower to enhance coverage on the south side of Milwaukee for the two-way radio system and emergency communication. "We tried to capture and capitalize on every strategic advantage the site's location and height had to offer," Kis said.

The building is wired for the 21st Century voice and data needs. A SONET network for voice, and gigabit Internet for data, connect the desktop computers using single mode fiber capable of ten gigabits of data. Twenty-four single-mode fibers are available in the building.

As part of the remodeling, a telephone node was installed in the building, which includes a G650 AVIA, PBX switchgear connected using City-owned fiber capable of handling 400 digital and analog telephones. Investigating and correcting the existing conditions turned out to be a monumental task during remodeling.

Old tower meets current Americans with Disabilities Act (ADA) requirements
Originally, the Town of Lake Municipal and Water Service offices had been housed on the first floor, in the east wing. In the west wing and center of the building were empty water settling tanks, an old electrical room, and outdated generators. The second floor had been used for storage and some office staff, the third floor was used as a practice area by the Town of Lake Band, and the fourth floor held communications equipment, and all showed signs of water damage. However, the most extensive water damage was located on the fifth level where the metal drip pan for the one million gallon water tank, which rose approximately fifty feet above it, was covered with rust.

In order to utilize the 25,657 square feet located in the first four levels, the building's steel structure was upgraded to comply with current building codes. The exposed steel was protected with fireproofing material, a sprinkler system was added, and electrical and data services were updated. The outdated existing mechanical rooms on the first floor were abandoned and new mechanical equipment was installed on the fourth floor. Remodeling also included new ADA-compliant restrooms, installation of an elevator, new doors, walls, counters, flooring, and lighting.

Historic character preserved, use expanded
Because of its historic significance, care was taken to preserve the original appearance of the exterior of the building. We also restored, as close to original as possible, the two-story east lobby with its art deco-style moldings, massive aluminum and amber glass chandeliers, and two open staircases with metal chevron and diamond detailed balusters. Birch-paneled counters and the new elevator were designed with chevron and diamond patterns to match the art deco details found both outside and inside of the original building. New finishes were selected to coordinate with the existing terra cotta and ochre lobby colors.

Before

• Existing office space utilized 2,203 sq. ft.
• Original storage was 2,800 sq. ft.
• Water Works/mechanical was 5,118 sq. ft.
• Maximum staff accommodated 47 persons

Now

• Increased usable space to 25,657 sq. ft.
• Increased office space to accommodate 101 staff
• Additional conference space for 99

In order to fully realize the potential of this building the Department of Neighborhood Services, the Vector Control staff, and staff from the downtown Zeidler Municipal Building were consolidated in the renovated Water Tower and Municipal Building. The result was a tremendous increase in operational efficiency for the department.

ADA Code building challenges
ADA building codes required an elevator to the four floors. While an elevator shaft existed, the elevator car and mechanism had to be installed. All floors and walls were upgraded to meet the current fire rating. Restroom accessibility was completed and a ramp was added to the front entrance.

Other building challenges

• The exterior of the building could not be appreciably altered. The interior lobby could not be altered.
  
  
• A fourteen-inch-thick concrete wall that separated the public half of the core had to be removed and substantial floor leveling was required after removal of the center wall.
  
  
• Goodbye obsolete electrical service! Hello Energy Star: Much of the electrical service and switchgear dated back to 1938 and was considered obsolete. Live opening and closing of the 3,810 volt disconnects and switches were considered unsafe. The service was completely replaced with a 300 KVA transformer that supplied 4,160 volts stepped down to 480/277 volts through two service laterals. A 225 KVA transformer supplies power for emergency and life safety, while a separate lateral supplies the 300-amp power at 388/277 volts dedicated service for the fire pump.
  
  
• Energy Star-certified HVAC equipment was used throughout: The two main air handling units supplying 5,000 and 12,000 CFM are each equipped with free-cooling economizer cycles and high-efficiency fan motors. Two, one-million BTU, 87% efficient hot-water boilers provide the hot water for air handling and fan coils, the unit heaters, and for the perimeter baseboard radiation. A fifty-ton air-cooled chiller that is rated with part load efficiency (1PLV) of 14-2 provides cooling. A direct digital control system monitors and operates the building's HVAC and newly-installed fire-life safety system that also includes a sprinkler system.
  
  
• Peak-load shaving using a microturbine while reusing wasted heat: The building has a peak load of 320 Kilowatts. The 60 kW capstone gas-fired microturbine operates during on-peak hours, and during some of the coldest months wasted heat from the microturbine is reclaimed. It is estimated that the use of the microturbine will generate $4,420 per year in savings.

Green Building Initiatives

• Remodel and reuse versus new construction
• Operable windows
• Energy Star-certified mechanical systems
• Direct Digital Controls for HVAC
• Air-to-air heat exchangers to temper outside air
• Permeable pavement used for additional parking
• Day lighting
• Installation of Ethylene Propylene Diene Monomer (EPDM) white roof
• Maintaining green space
• Insulated exterior doors
• Restrooms with water conserving fixtures
• Historic light fixtures preserved and retrofitted with energy efficient ballast
• Sections of concrete walls used by a salvage company as yard dividers

Babette Kis, A.I.A., can be reached at (414) 286-8333; Venu J. Gupta, P.E., a member of APWA's Facilities & Grounds Committee, can be reached at (414) 286-3401 or at vgupta@mpw.net.