Canadian Consulting Engineer

Heritage Sustained: Calgary Public Building

 

May 1, 2013   By Rob Guenther, CET, Stantec Consulting

 

For the first time, a city-owned public building in Calgary has achieved Platinum status for LEED for Commercial Interiors –and it’s an 80-year-old structure.

Mechanical engineers and energy efficiency experts from Stantec worked with the City of Calgary and principal architect the marc boutin architectural collaborative to design the renovation of the Calgary Public Building and transformed the aging building into a pillar of sustainability.

Mechanical engineers and energy efficiency experts from Stantec worked with the City of Calgary and principal architect, the marc boutin architectural collaborative, to design the renovation of the Calgary Public Building. They transformed the aging building into a pillar of sustainability.

Originally built in 1931 and designed by architect T.W. Fuller, the eight-story reinforced concrete structure stands next to Olympic Plaza on 8th Avenue in the city’s downtown. The iconic building is a beautiful example of the Modern Classical style, with a Tyndall limestone exterior and massive Ionic columns that mark the north and west facades.

The building was designated a Municipal Historic Resource in 1996 and today is the home of the Epcor Centre for Performing Arts. It also houses a variety of municipal administration offices.

A major design objective for the restoration project was to increase the occupants’ satisfaction. Russ Golightly, project manager for the City of Calgary, says: “Success in the effort would be measured by a reduction in the frequency and volume of requests for service calls stemming from poor indoor environmental quality in the existing facility.”

Another goal established was to create a landmark facility for Calgary by integrating the best of modern sustainable design in a historical restoration. As such, the project team had to determine the most appropriate way to conserve the character-defining historic elements, while making it a leading-edge sustainable office building.

Blending old and new technologies

Since the exterior of the building had to remain intact, an innovative approach was needed for upgrading the building envelope. The solution was to add a high performance liner on the interior. The liner incorporates additional insulation within a new wall cavity built from metal studs and drywall. New high-performance operable windows were also added.

A major strategy on the project involved using the existing passive design features of the original 1930s building, many of which had been decommissioned over the years. The original building was passively cooled and naturally ventilated through the use of operable windows, open floor plans, and the stone and masonry structure’s considerable thermal mass, which had helped to regulate temperatures over a 24-hour period. Many of the windows had been sealed shut over the life of the building, and the floor plan had become cellular. Some rooms completely lacked access to windows and much of the exposed thermal mass was covered. Working with the design team, Stantec reinstituted and optimized the passive strategies offered by the original architecture, creating a more open floor layout, and exposing thermal mass where possible.

To complement the passive (and largely forgotten) design techniques of the 1930s era, modern technologies were added. The natural ventilation and passive cooling, for example, was supplemented with chilled beam technology. Stantec’s design was one of the region’s first installations of active chilled beams. Since the focus of the forced air system is to chill the beams within the ceiling rather than the entire space, these systems are much smaller than traditional systems, are extremely quiet and reduce the fan noise that is typical in office buildings. They also use about one-sixth of the air supply in a traditional system and therefore allow smaller duct work, leading to significant energy savings. To the casual observer, however, the system merely looks like a small vent in the ceiling. Additionally, the approach permits flexibility for working with the varied ceiling heights present in this heritage building.

Stantec also designed a solar hot water system on the roof for domestic hot water heating, while the building heating requirements are met by connecting the building to the city’s new district energy service.

The owner wanted the sixth floor of the building to be returned to a 1930s layout, with the same fit and finishes as the original building. Stantec worked with the interiors team to select water fixtures in the washrooms that closely resemble those from that time period, while offering modern performance such as low-flow technology.

Measurement and verification

All of the mechanical and electrical systems include measurement and verification (M&V) technology that allows the City of Calgary to confirm the energy savings that were predicted during the design phase. With additional metering beyond the standard gas and electric meters, the owner can keep track of the energy consumed by different systems such as lighting, elevators, fans, hot water etc.. The system allows the owner to know what a properly performing building has for an energy profile and to quickly zero in on a problem if energy consumption starts to climb.

In addition to the M&V technology, a unique digital commissioning system developed by Stantec gives each piece of commissioned equipment a barcode that can be scanned with a tablet computer during and after construction. The tool enables the building management team to access installation, operations and maintenance, commissioning, and shop drawing data on every device. Approximately 600 pieces of equipment were captured in the Stancheck system with 35,000 individual data points.

Benefits all round

“The Calgary Public Building could not have been preserved as a meaningful municipal historic resource if this renovation had not taken place,” explains Golightly. “The city has observed a significant reduction in service calls and a welcome improvement in occupant satisfaction rates as a result of the project.”

The building was honoured with an Alberta Consulting Engineers Award of Excellence for Sustainable Design, and an Award of Merit for Building Engineering in 2013.

The result of the renovation is a cold-climate case study that demonstrates that existing heritage buildings do not have to be demolished. Rather, they can be successfully renovated to the highest standards of environmental stewardship without sacrificing cost, energy efficiency, or preservation standards.

“Achieving LEED Platinum was quite an accomplishment for a new building, but we were faced with the challenge and the opportunity of renovating a heritage building in the heart of downtown Calgary that was built to 1930s standards,” says James Furlong, CET, Stantec’s principal in charge of the project.

“The results of this design are better than anyone expected,” says Furlong. “The energy consumption is so low (approximately 50% less than similar buildings), the utility meters had to be checked to make sure they were still working properly.” cce

Owner: City of Calgary

Mechanical/energy/commissioning consultants: Stantec Consulting (James Furlong, CET, Jeff Rent, P.Eng.,
Rob Guenther CET, Eugene Hayes, Tom Pilmoor C.Tech.)

Prime consultant and architect: the marc boutin architectural collaborative inc.

Additional architects: Perkins + Will; Mark Chambers Architect

Electrical: Mulvey + Banani (Alberta)

Structural: Read Jones Christoffersen

Contractors: Chandos Construction, Polar Bear Mechanical

 


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