Biological Sciences Remake

At the heart of the University of British Columbia campus two wings of the aging Biological Sciences complex have been completely transformed. The South Wing, which dates from 1957, and the West Wing which dates from 1970 and faces Main Mall, were gutted and renovated in a 19-month project, officially reopening in August.

Acton Ostry Architects led the design team, which had Read Jones Christoffersen as structural engineers, and MCW as the mechanical-electrical engineers.

The $47-million, 170,000 sq. ft. project was completed as part of the University of British Columbia’s Renew program, which aims to repurpose and rehabilitate outdated buildings rather than replace them.

The four-storey renovated wings now have state-of the art laboratories, aquaria, research spaces, classrooms, offices and gathering spaces for the Departments of Botany and Zoology.

According to an associate professor in the university’s Department of Zoology: “Acton Ostry transformed a bland, outdated and ineffectual academic building into an exciting and vibrant research environment.”

Energy systems a tight squeeze

“It’s a beautiful building,”says Adam Juck, P.Eng., an associate with MCW Consultants and the mechanical engineer of record for the renovated complex. His appreciation of the architecture was honed during the early design stages when the engineers were faced with having to squeeze entirely new mechanical and electrical systems as well as special laboratory infrastructure into the existing 1960s-era structures.

“I’d say we had about 50% of the ceiling depth we needed from an ideal standpoint for many areas in the building,” says Juck. As a result, “All the services — electrical, mechanical, as well as lab services such as medical gas and industrial water — were competing for space within the existing structure.”

With a new building, the structural engineers can coordinate their design to satisfy the mechanical engineers’ requirements for service shafts. Here, however, the existing structural members sometimes had to be cut to make space for the mechanical systems. MCW and structural engineers RJC worked together to select the most practical locations for the structural changes.

The renovated building is designed to achieve LEED-Gold certification and is predicted to use 41% less energy than a standard building of its type. Laboratory buildings require large amounts of fresh air, which requires lots of energy, so 41% energy savings “is fantastic” says Juck.

A special centralized water-to-water heat pump system is a key factor in the energy savings. Whereas most heat pump systems use the ground, a lake or an aquifer as their thermal energy source, this system uses the equipment in the building itself as its thermal energy source. “Thanks to the water-to-water heat pump system, we are pulling heat from areas that are producing a lot of heat and sending it to areas that need it,” says Juck.

The heat pumps serve a closed loop hydronic system, providing its primary source of low-temperature energy. The campus central steam plant provides supplemental energy only as required during peak periods. Advanced controls help to optimize and balance the system.

The centralized water-to-water heat pump system consists of nine 45-ton pumps, five in the West Wing and four in the South Wing, located in their mechanical rooms. The pumps have total cooling capacities of 225 and 180 tons respectively, and heating capacities of 3,600 and 2,600 MBTU/hr. During the cooling season, excess heat is rejected via roof mounted fluid coolers.

The perimeter offices use low temperature hot water radiation for heating, and have operable windows for natural ventilation, providing significant energy savings.

In a laboratory building there are lots of special situations to enable the heat exchange to take place in the heat pump system. For example, Juck explains, the building has freezers running at -80 degrees C and each of them is giving off a lot of heat. Some rooms have 25 of these freezers. “In the past you would just exhaust that hot air from the roof of the building,” says Juck. “In this building the heat is pulled out through a fan coil unit and becomes the source heat for the closed-loop hydronic space heating system.”

Heat is also fed into the heat pump system from the Environmental Chambers. Used for fish and animal testing, the chambers are “basically a large room that is essentially a big refrigerator inserted into the structure,” says Juck. Though the chambers have their own separate and independent heating and cooling systems, MCW was able to harvest the heat they give off and feed it into the centralized heat pump system.

UBC’s health and safety department asked for 10 air changes an hour in the laboratories in the Biological Sciences Building, but MCW were able to show through a computational fluid dynamic model that they could achieve safe conditions with 8 air changes an hour — thereby saving energy.

Further energy savings are met by using a manifold exhaust system for most of the 50 lab fume hoods, which allowed heat reclaim coils to be attached to it. –BP

STRUCTURAL RENOVATIONS

Built in 1970, the west wing of the Bioscience Building is a five-storey cast-in-place concrete structure. The retrofit required completely stripping the interiors, and the structure had to be seismically upgraded.

Since it was not necessary to meet the seismic code requirements for new construction, it was felt that upgrading to meet 75% of the 2005 National Building Code requirements would reduce costs and yet provide good performance in a large seismic event.

Although the structure contained a number of reinforced concrete walls, their capacity to resist seismic forces was limited and the reinforcing detail was not suitable for ductile behaviour. A new ductile concrete shearwall system was therefore designed to resist all the seismic loads.

As this was not a heritage building, we took the approach of locating the seismic upgrading system on the exterior of the building. The approach minimized costs and gave more flexibility for planning the interior spaces. Working in close collaboration with the architect, we developed an exterior system of concrete walls and buttresses which, in addition to providing seismic resistance, provided articulation and architectural interest to the west facade. Illuminated and decorated glass panels were mounted on the outside of the concrete buttresses, lending added drama at night.

Locating the seismic walls on the exterior of the building simplified construction and reduced time and cost. However, a disadvantage was that the walls could not mobilize much of the building’s own weight to help reduce the seismic overturning moments on the walls and footings. To minimize the size of the foundations, therefore, vertical soil anchors were incorporated in the footings.

The smaller four-storey South Wing, built in 1957, was also of concrete construction, so we used a similar approach of adding ductile concrete shear walls. Since the site did not lend itself to adding exterior shearwalls, we added two sets of “L” shaped ductile concrete shearwalls in inconspicuous corners in the interior of the building to provide the necessary seismic resistance. These walls were placed adjacent to existing concrete walls to minimize their impact on windows and facilitate space planning. In this case we were able to mobilize a significant portion of the building’s mass to help resist overturning forces, thereby reducing the size of the footings. cce

Read Jones Christoffersen (Renato Camporse, P.Eng., Phoebe He). Mechanical/electrical engineers: MCW Consultants (Adam Juck, P.Eng., Andrew Burt, Greg Lord, P.Eng.). Architect: Acton Ostry Architects. Other key players: Research Facilities Design (laboratories), Scott (general contractor), Division 15 Mechanical (mechanical contractor)