One of the most sustainable strategies available in the design and construction industries is to reuse or repurpose an existing building. Not only is energy preserved from fabrication, transportation and labor embedded in the original struc- ture, but in many cases, the building’s history, context and sense of place within its community also is preserved.

In today’s economy, a revitalized office building enhanced with energy-efficient systems and sustainable finishes is the solution for tenants seeking the cost savings, healthy work environment and lower carbon footprint associated with green office space. Plus, potential tenants’ real-estate options aren’t limited to one location or type of building, nor do they have to sacrifice brand identity or amenities, such as conference areas, fitness facilities or a welcoming lobby space.

Last year, HGA Architects and Engineers, Minneapolis, transformed the iconic First National Bank building in downtown St. Paul, Minn., into a more desirable multi-tenant office building. The structure, which spans an entire city block, comprises three buildings—the east tower, built in 1915; west tower, built in 1931; and north tower, built in 1970. A 17th-floor copper skyway connects the 33-story west and 16-story east towers.

The complex was long in need of revitalization and the new owner was keen about preserving the building’s ornate detailing and historic heritage while upgrading tenant standards, introducing sustainability and adding amenities that would transform the landmark structure into a highly desirable office building. HGA Architects and Engineers reallocated resources, reconfigured space, and retrofitted mechanical systems and utilities to extend the towers’ usable life, enhance their flexibility and improve their marketability.

An Eye on Infrastructure

Despite a downsizing trend in St. Paul for several years, the First National Bank has maintained its occupancy of about 76 percent, according to Aaron Barnard, director for Cushman and Wakefield in Minneapolis, the leasing agent for the property. The tenant mix includes law firms, financial-management offices, nonprofit organizations and the State of Minnesota’s Department of Employment and Economic Development, which occupies several floors.

A large portion of the multimillion-dollar project was spent on infrastructure—improving the efficiency of the mechanical systems, installing new plumbing with low-flow fixtures, incorporating light sensors and compact fluorescent bulbs that reduce electricity use, and adding modernized elevators with existing ornate doors. For instance, subcontractors meticulously replaced all the badly corroded and inefficient water lines in all three towers without damaging architectural details. Concurrently, HGA Architects and Engineers replaced a previous water system that ran continuously, pumping water to the top of the building and sending it back down again. With the new series of pumps, water is regulated and pumps turn on and off as needed to pressurize specific sections of the building. Because the pumps aren’t running continuously, the owners have been able to save electricity.

In the first-floor lobbies, stonework, marble walls and columns were repaired and lighting was improved. The team cleaned and repaired terrazzo floors on the street and skyway levels and replaced old floor coverings with carpet that contains recycled content. The elevator lobbies were rehabbed using a panel system made out of wood fiber and resin. Additional sustainable-design initiatives that are visible to tenants, such as recycling stations on each floor and high-performance glazing on windows throughout the building “create an expectation that just doesn’t exist in a lot of other Class A office buildings, which is that sustainable design not only saves energy and therefore costs for the tenant, but it’s the right thing to do,” Barnard says. “We view sustainability as a good case for tenant retention.”

Tenant Pride

The sustainable advantage is especially appealing to government tenants, like the state of Minnesota, which recently passed an amendment to the Minnesota Sustainable Building Guidelines requiring all new state structures to reduce fossil-fuel energy use by 90 percent by 2025. Although the Department of Employment and Economic Development’s offices in the First National Bank building aren’t new construction, the building is energy efficient, Barnard says. “In fact, we are engaging in a dialogue with the state of Minnesota about being in line and in tune with the [state’s] future goals for sustainability.”

HGA Architects and Engineers also ensured the building would attract and retain tenants by capitalizing on its historic character while adding contemporary amenities in a sensitive way. Tenants find out about improvements via electronic newsletters and the building’s Web site, www.firstnationalbankbuilding.info.

Amenities found in newer office buildings also are available in the building. For example, wireless Internet and audio/visual technology are accessible throughout a conference center on the ground floor, which has a suite of training and meeting rooms that seat up to 48 people. Such conveniences allow tenants to meet their conferencing needs on-site without increasing their office footprint or expending energy by going off-site.

The First National Bank building’s mission was to restore the structure’s timeless integrity while introducing inviting public spaces and attractive tenant amenities and incorporating cost-saving, energy-efficient and health-promoting green strategies and materials wherever possible. The leasing agency likewise is committed to continuing these sustainable initiatives because today’s business tenants, who are increasingly savvy about the good will and smarter bottom line created through a greener approach to doing business, are asking for them. By meeting all of these goals, HGA saved a historic building beloved by the citizens of St. Paul and enhanced the building’s marketability for another generation of occupants.