September 1, 2008
In the spring of 2005, the University of Calgary (U of C) initiated a request for proposals (RFP) for its Child Development Centre (CDC). The intent was to build a highly sustainable centre for child development on campus land, with a focus on supporting organizations working together for the benefit of children (and their families) with a range of developmental conditions. The vision, budget, and timelines were ambitious.
The school clearly expressed two requirements. One was to make stronger connections between child development practice and research as well as providing much needed childcare space. The other was the university’s mandate to build all new capital projects to a high sustainable standard—the requirements stated a Platinum rating must be obtained under the Canada Green Building Council’s (CaGBC’s) Leadership in Energy and Environmental Design (LEED Canada) program.
LEED Platinum had never before been achieved in Alberta. Further, no Canadian project of the CDC’s size had ever achieved the 52 LEED credits necessary. As usual, there was the ever-present challenge of a limited budget and an aggressive schedule. This article examines how the CDC came to be, addressing sustainable strategies from site design and material specifications to interior finishes and mechanical systems.
Building site and exterior
The 113, 800-m2 (125,000-sf) CDC is four storeys, with one level of underground parking. As its composition was directly tied to its location and microclimate (the building is designed to optimize several passive strategies), the first—and most critical—step was site selection.
In this case, the project team was given four sites from which to choose. The two most northern sites had an existing tree farm and no developments surrounding them. The third site was located directly across from the main entrance of the Alberta Children’s Hospital and had limited access to services. The fourth most southerly site had north- and south-facing site access and a greater location presence (i.e. it offered a gateway to University of Calgary’s West Campus). As each site was analyzed, a list of advantages and disadvantages was formulated, reflecting the university’s needs and the sustainable attributes available. The fourth site was chosen as it clearly had the most potential to fulfill the design objectives. Its advantages included:
• ideal building form to take advantage of passive solar strategies (the building is elongated on its east–west axis for increased winter sun exposure, which also limits the east and west face’s exposure to heat gain and glare, and reduces peak cooling loads);
• close access to public transit (i.e. four regularly serviced bus routes), helping earn LEED points under Sustainable Sites (SS) Credit 4, Alternative Transportation;
• connections to recently developed stormwater ponds, for LEED points under SS Credit 6, Stormwater Management;
• synergies with neighbouring buildings, through shared use of meeting rooms, lounge, cafeand parking;
• easy access to existing roadways and bike pathways;
• magnificent views of the escarpment;
• ability to build close to existing streets and neighbouring buildings (including supporting programs in the centre such as the Alberta Children’s Hospital and Ronald McDonald House) to create a more urban fabric;
• future development potential; and
• abundant amounts of open space for playgrounds and parks.
The real test of the project’s integrated design approach began when the building’s form was developed. It was quickly discovered how much outside influences affect the design of space and systems. For example, one of the primary drivers to improve the energy performance was the amount and location of windows. The team wanted the building to incorporate natural light, but the uncontrolled heat gain needed to be managed.
To deal with this issue, photovoltaic (PV) panels were employed to serve a dual purpose: provide renewable energy and shade the south glazing, thereby reducing peak cooling loads. East and west facades were also difficult to control during certain peak periods of the day; consequently, a lower percentage of windows was placed along those elevations.
As part of the design vocabulary, each elevation was expressed differently based on its orientation. Through collaborations with the electrical, mechanical, structural, and energy modelling consultant, the team developed a lightweight photovoltaic sunshade along the south facade, providing the building with more than 11 per cent of its energy consumption. The windows on the east and west facades were integrated with a coloured aluminum composite panel (ACP) system, forming a mosaic pattern. Additional clerestory windows stretched along the entire north elevation, providing the interiors with abundant diffused daylighting through their positioning.
From the outset, the vision was to integrate different disciplines of the university’s research departments with Calgary Health Region practitioners functioning within the space—beyond specialized spaces, the building needed ‘free zones’ that anyone could just hang out in. This concept developed into an open multi-purpose room on the main level that can be used to hold events or have meetings. There is also a second-level lounge that has a piano, Eames lounge seating, and a large, publicly accessible south-facing balcony for taking in the views. These areas allow for connecting with the community and an informal place for faculty and staff to meet with colleagues or simply relax.
The childcare area on the west portion of the main level has wide corridors with interior windows set at heights that children can look through, ranging about 0.46 to 0.91 m (1.5 to 3 ft) from the finish floor to the window’s sill height. All spaces inhabited by children from 7:30 a.m. to 5:30 p.m. have exterior windows and direct access to age-appropriate playgrounds. There is an expansive kitchen and large interior play area. These features contribute to making the CDC an attractive working environment, helping the facility find and retain childcare workers (of which there is a serious shortage in the city).
Recycling centres have been incorporated into the interior design in locations throughout the building to cut down on the wastestream. Also throughout the building are operable windows, which allow occupants to individually control their environment. This is one of the most successful strategies for providing a comfortable working/learning space for users.
The remainder of the second, third, and fourth floors are left as unfinished tenant space. The intent is to allow groups focused on research and practice in child development to occupy the space and, through their adjacency, stimulate a vital and collaborative environment.
Currently, the main level hosts a childcare centre, as well as a cafe and meeting rooms in a multi-purpose area. The Calgary Health Region’s Child Development Services occupies the second floor. The top two floors are still vacant.
Since the Child Development Centre was striving for LEED Platinum, significant energy savings were required. This necessitated a comprehensive approach to building orientation and the planning/design of the program, systems, and envelope. The goal was to achieve high performance through the most simple and elegant means—a strategy that meant using efficient equipment and focusing on low internal gains, low envelope exchanges, heat recycling, and double-duty systems for lighting, heating, cooling, and ventilation.
Using the 1997 Model National Energy Code for Buildings (MNECB) compliance path, the project saw substantial energy savings of 71 per cent. This significant achievement garnered all 10 of the available points under LEED’s Energy and Atmosphere (EA) Credit 1, Optimize Energy Performance. The energy required to power the building is supplied from the utility provider’s wind farms, with 11.2 per cent supplied by the largest solar panel installation integrated into a building network in Canada. EE4 modelling, a building energy simulation software system, was used to scrutinize both equipment selection and design decisions throughout schematic development.
The lighting strategy at the CDC effectively harvests daylight where possible and optimizes lighting levels. The average power density is very low (i.e. 7.3 W/m2) in comparison to a typical reference building (i.e. 17.9 W/m2). One of the biggest energy savers was the use of occupancy controls throughout the building to ensure lighting is only employed when there is someone in the room. Lighting and ventilation systems also automatically shut down outside of operating hours.
Another strategic decision was to keep the parking garage level cool. The exclusion of heating from this area allowed the project team to rule out this area in energy collections. The energy model does not include the underground parking level as it was considered an un-heated space. By installing additional insulation in the parkade (to the underside of the main level), R-values for insulation increased from R-7 to R-10, energy costs were lowered for the entire project, and the floor of the main level was kept warm.
In terms of mechanical systems, the CDC’s HVAC is a comprehensive design involving carbon dioxide (CO2) sensors, occupancy controls, variable air volume (VAV) boxes, and variable speed motor drivers for heating and cooling. This controllable and responsive system serves to condition areas as required, as opposed to always maintaining comfort conditions. Further, radiant cooling panels on the south perimeter efficiently handle the higher peak loads created by the sun. Ninety-six-per cent efficient boilers, high-efficiency chillers with variable speed or modulating capacities, drive the systems.
The ventilation system uses a displacement design. Air is provided primarily through a raised floor system (i.e. under-floor air ducts)—or in some cases, a low sidewall discharge system—at a very effective range of 2 to 2.7 L/s m2. Most LEED points obtained here relate to EA Credit 1, Optimize Energy Performance.
Discussions among project team members on how to deal with promoting water reuse (as an alternative to collecting rainwater with a cistern) led to an unexpected discovery. An abandoned service pipe from the central heating plant to the east of the project site was found during excavation. This served as an easy, low-cost means of bringing process water from the heating plant into the CDC to service the water closets. The water reuse system scored LEED points under Water Efficiency (WE) Credit 2, Innovative Wastewater Technologies.
Potable water savings of 59 per cent were realized through the selection of efficient low-flow, dual-flush toilets, waterless urinals, and flow restrictors driven by infra-red sensors.2 LEED points were earned under WE Credit 3, Water Use Reduction, and Innovation and Design Process (ID) Credit 1, Innovation in Design, for exceeding a 40-per cent reduction in water use. All stormwater from the site is connected to the storm pond south of the CDC on U of C West Campus lands. The stormwater ponds were constructed to exceed U.S. Environmental Protection Agency (EPA) quality standards for removal of total suspended solids (TSS).
Careful attention was given to the materials specified for the building to maximize recycled content and minimize off gassing, essentially improving indoor air quality (IAQ). For example, as part of the focus on responsibly harvested and local materials:
• more than 70 per cent of the wood was harvested from sustainable forests and certified by the Forest Stewardship Council (FSC);
• 20 per cent of materials contained recycled content;
• 24 per cent of materials were locally extracted and manufactured; and
• more than 80 per cent of construction waste was diverted from the landfill.
For the above percentages, ‘materials’ include all those used in construction, from formwork to interior finishes.
Recessed entry mats
All major entries to the building have permanent recessed entryway systems—either roll- up aluminum rail mats or linear rib-pattern roll mats—that catch and hold dirt to prevent contamination of the building interior.
High fly-ash concrete
Fly ash, an inorganic by product generated by Alberta’s coal-fired electrical generation plants, replaces traditional concrete mix ingredients that require energy (e.g. portions of lime, cement, and crushed stone).3 The fly ash content in the slabs, walls, and footings is more than 50 per cent. The concrete high fly-ash mix designs used on the project produced a total of 75 per cent post-industrial recycled content. LEED credit was earned under Materials and Resources (MR) Credit 4.1, Recycled Content: 7.5% (Post-consumer and ½ Post-industrial).
A retro-plate system requires several passes with grinding and polishing equipment in conjunction with a chemical densifier to change bare concrete into a very abrasion- resistant and durable surface. This system was used in the main-level multi-purpose space. For concrete polishing, this technique minimizes concerns regarding flooring replacement and maintenance (only regular damp mopping is necessary).4 The polished floor which is relatively inexpensive over its lifecycle, also increases reflectivity up to 30 per cent to take advantage of daylighting.
Cork flooring was used in the childcare circulation areas. The material comes from the bark of the cork oak tree from Mediterranean forests. Cork is considered a renewable resource because the trees are stripped of their bark every nine to 14 years. The tree itself is never cut and the habitat remains undisturbed. Many benefits include ease of maintenance, resilience, cushioning, and ‘warmth’ underfoot. This flooring contributed toward earning LEED credit under MR Credit 4.1, Recycled Content: 7.5% (Post-consumer and ½ Post-industrial).
All the paints, primers, and coatings used in the project are low in volatile organic compounds (VOCs), the components vaporizing at normal room temperature that are harmful for the environment and building occupants. These low-VOC materials provide a more comfortable and healthy environment, and helped earn LEED credit under Indoor Environmental Quality (EQ) Credit 4.2, Low-emitting Materials: Paints and Coatings.
The CDC has a single-ply, polyvinyl chloride (PVC) roofing assembly that meets Energy Star label requirements for high reflectivity and emissivity.5 This type of roof can help reduce the urban heat island (UHI) effect and the ensuing impact on the microclimate, earning LEED credit under SS Credit 7.2, Heat Island Effect: Roof.
Carpeting and adhesives meeting the Carpet and Rug Institute’s (CRI’s) Green Label certification were used throughout the building to improve IAQ. Green Label carpets and adhesives are low-emitting and better for occupants as they release less harmful chemicals than typical products.6 The Green Label seal indicates products contain among the lowest-emitting carpet, adhesive, and cushion components on the market.
Transportation and landscaping
Alternative methods of transportation were of high consideration when choosing the site and determining the design strategy. The CDC directly links to the Calgary regional pathway system; in fact, the pathway runs right in front of the facility. The building also has the required shower and change room facilities and bike racks to encourage cycling to work, and contributed to LEED points under SS Credit 4.2, Alternative Transportation: Bicycle Storage and Changing Rooms. Calgary has implemented several new bus routes to increase service to the new Alberta Children’s Hospital, which also benefits the tenants and users of the adjacent CDC.
The underground parking area eliminates the negative impacts of asphalt surface parking and promotes carpooling with dedicated carpool stalls.
Within the project boundary, more than 50 per cent of the site has been rejuvenated into a naturalized landscape, earning LEED credit under SS Credit 5.1, Reduced Site Disturbance: Protect or Restore Open Space. Described as a ‘naturescape,’ the low-maintenance, self-sustaining design does not require irrigation. It uses drought-tolerant and low-maintenance local trees, shrubs, and groundcover to create an active landscape for playgrounds and outdoor gathering spaces, while also improving the microclimate around the building to provide shade and protection from the wind.
The importance of good teamwork
One of the most powerful outcomes from this project was the culture that developed within the project team. All parties were committed to a common sustainable vision; this meant meeting monthly throughout the design and construction phases. The fact everyone had something meaningful to contribute fostered respect and understanding between the disciplines. There is something powerful about trying to reach the highest level of LEED.
The design was developed with an inherent flexibility so costs could be managed. Three options for the exterior skin were tendered—composite aluminum wall panels, 3.2-mm thick aluminum panels, and 1.2-mm thick zinc panels. (The least expensive option—zinc—was selected.) This allowed for more choices in terms of managing sequential tendering as the project progressed. Since tenants were not all defined at the onset of the project, change was constant, with the ability to adapt playing a central role. Randomness became part of the building ‘language,’ the mosaic patterning and the shifting windows were developed unsystematically. The project required a balance between order and ambiguity as part of the architectural concept.
The Child Development Centre achieved LEED Platinum in October 2007, making it the largest building in Canada to do so. However, with respect to sustainable design, new ways of building come with unforeseen challenges. The centre’s users are only now learning to live and work within a healthier indoor environment. As time passes, it will be easier to review whether the concepts put in place really are as beneficial as intended. Consequently, CDC has been set up with extensive monitoring to confirm its social and comfort performance.
Any new direction into how the design team moves forward comes with feedback from those who inhabit the building. Will adding change/shower rooms increase the number of commuters who bike to work? Will favourably locating carpooling stalls provide enough incentive to get people to start travelling to the office together? Does the under-floor system truly provide the flexibility promoted? Will users take on the responsibility of closing the windows when the temperatures drop?
For there to be a shift in how we build (and occupy) buildings, there must also be a deeper realization that what we do daily has significant impact on our environment and market place. The CDC emphasizes the creation of an ever-evolving community in support of child development. It was built within a tight economic budget during a time of rising construction costs and shortages of skilled workers and, due to the expertise and commitment of the team, the final result is a high-quality design that has minimal impact on the environment.
1 For more information on the courts project, see “The Calgary Courts Centre: Developing a winning strategy and setting a design precedent,” by Bill Chomik, AAA, MAIBC, FRAIC, Hon. FAIA, RCA and Lois Wellwood, BID, NCIDQ, ARIDO, IDA, IDC, in the March 2006 issue of Construction Canada.
2 For more on these types of fixtures, see “Going with the Flow: Water efficiency in commercial projects,” by Winston Huff, CPC, LEED AP. The article appeared in the January 2008 issue of Construction Canada.
3 Additional information on supplementary cementitious materials (SCMs) like fly ash can be found in “Nanotechnology for Greener Concrete,” by Taijiro Sato, PhD. See the article on page XX.
4 For another look at polished concrete, see “Reflecting on Polished Concrete Floors,” by Greg Schwietz, CSI, CDT, on page XX.
5 Promoted by Natural Resources Canada’s (NRCan’s) Office of Energy Efficiency, the Energy Star program was created by EPA.
6 For more information on the program, visit www.carpet-rug.org.
Judy MacDougall, AAA, LEED AP, is an associate at Kasian Architecture Interior Design and Planning’s Calgary office. She was the Project Architect for the Child Development Centre (CDC) project. MacDougall has experience working on sustainable building and energy design strategies for a range of project types including large mixed-used developments, educational facilities, and institutional projects. A LEED-accredited Professional, she has also participated as a committee member in the Alberta Chapter of the Canada Green Building Council (CaGBC) and leads the Kasian Sustainability Task Force for the firm’s Calgary office. MacDougall can be contacted via e-mail at firstname.lastname@example.org.
Project Details and Team
Project: Child Development Centre
Client: University of Calgary
Year: March 2005-August 2007
Area: more than 11,600 m2 (125,000 sf)
Project management: RC Peterson
Construction management: Ellis Don Construction
Architecture: Kasian Architecture Interior Design and Planning Ltd
Interior design: Kasian Architecture Interior Design and Planning Ltd
Structural engineering: Read Jones Christoffersen
Mechanical and electrical engineering: Wiebe Forest Engineering
Energy consultant: Jim Love Faculty of Environmental Design
Landscape architecture: Scatliff Miller Murray
Civil engineering: MMM Group
Programming: HFKS Architects Inc
Elevator consultant: Lerch Bates North America Inc.
Code consultant: Spitula & Associates
Specifications: PADA Specifications Inc.
LEED consultant: Green Building Services
Commissioning: Stantec Asset Consulting & Inspections
by Judy MacDougall