November 27, 2017
By Kevin Stelzer, OAA, NLAA, MRAIC, BSSO, LEED AP, Joanne McCallum, OAA, FRAIC, LEED AP, and Tony Cupido, PhD
The fundamental challenge of advanced sustainable design is not so much a technological issue, but rather a cultural one. The strategies, methods, and technology exist to make ultra-efficient buildings that can achieve 75 per cent less energy consumption than conventional buildings. There are also already systems that can power these low-energy buildings with renewable and low-carbon energy, such as onsite solar electricity and clean power utility grids. The real impedance to the adoption of ultra-low-carbon buildings, however, is the current culture of design and construction that clings to modes of delivery relying on the convenience of a carbon-rich environment. It is becoming ever more evident this convenience has been exploited beyond any resilient boundary.
In response, it is imperative to design buildings that not only employ the appropriate low-carbon technologies, but also inspire a renewed culture of the built environment—one where owners, designers, builders, and occupants no longer view the building as something mute and unresponsive, but instead as a system that demands the active participation of all stakeholders to achieve the most optimized performance.
This has been the mandate established by Mohawk College for the design of its new Joyce Centre for Partnership and Innovation on its Fennel Campus in Hamilton, Ontario. The project represents one of the first net-zero-energy institutional buildings in the region.
National pilot program
The Canada Green Building Council (CaGBC) defines a zero-carbon building as:
A highly energy-efficient building that produces onsite, or procures, carbon-free renewable energy in an amount sufficient to offset the annual carbon emissions associated with building operations.
The clear emphasis on carbon emissions underscores the urgency of addressing climate change by reducing greenhouse gas (GHG) emissions from buildings. Another component of the framework is “onsite renewable energy is incorporated into new construction projects to provide added resiliency, minimize offsite environmental impacts, and prepare buildings for a distributed energy future”—both key cornerstones of the Joyce Centre.
The building, which is a joint venture partnership with B+H Architects and mcCallumSather, was selected as one of 16 across the country participating in CaGBC’s two-year Zero-carbon Building Standard pilot project, which assesses the carbon performance of commercial, institutional, and multifamily buildings and warehouses. The goal is to help determine the requirements and standards for the Zero-carbon Buildings Framework.
When the doors of the Joyce Centre for Partnership and Innovation open to students in the fall of 2018, they will be greeted by 8920 m2 (96,000 sf) of solar-powered state-of-the-art labs, workshops, open study spaces, and lecture theatres, along with a new paradigm for sustainable building and learning in North America.
The project was granted funding under the Post-secondary Institutions Strategic Investment Fund (SIF) program. (See “Greener Buildings and Government Support.”) Challenged with a highly accelerated schedule to qualify for the federal government’s April 2018 Substantial Completion deadline (i.e. two years after the project was awarded), a unique, solutions-based collaboration amongst Mohawk College, B+H Architects/mcCallumSather, and EllisDon (the construction manager) was employed to achieve the ambitious net-zero energy performance target.
Starting with an energy budget
To navigate the pursuit of this energy performance goal, especially against the onerous energy demands of the engineering laboratory, B+H and mcCallumSather upended the typical design process, rooting their design in the development of an innovative energy budgeting strategy to help prioritize energy demands. Similar to any other significant project mandate, such as schedule or capital budget, this energy budget is honoured as a strict guideline to ensure the significant challenges associated with net-zero performance are appropriately articulated, categorized, and overcome.
To inform this exercise, the design team studied energy use intensity (EUI) values for known high-performance buildings in Canada. The team concluded that an annual EUI target of 75 kWh/m² was not only desirable, but also achievable for the programming, which consists of primarily classrooms, teaching laboratories, and collaborative learning spaces. (In the United States, this equates to 24 kBtu/sf annually, and 0.27 GJ/m² annually for Canadian government types.)
Creating the high-level vision
From the outset, the team recognized two important strategies—building enclosure performance must be exceptional, and active building systems must be ultra-energy efficient.
The HVAC design is based on a dedicated outdoor air ventilation system (DOAS) with local heating and cooling. The high-performance enclosure will maximize passive design strategies and significantly reduce the amount of heating and cooling required for the building mechanical systems. The DOAS is crucial to the design, as this type of HVAC system eliminates simultaneously having to heat and cool spaces, thereby providing superior air quality as return air is not recirculated in the building, while maximizing the exhaust air heat recovery performance.
Concept design energy use breakdown
A high-level energy model was created to investigate where energy would be used in the building and the potential impact of different HVAC approaches on the amount of onsite renewable energy required to achieve the net-zero energy target. Three lessons were learned from this exercise.
1. The building process and receptacle loads would be the single largest energy end-use in the building at an estimated 20 ekWh/m² annually.
This emphasized understanding how the building will be operated and what equipment will be plugged into its receptacles are critical to determining required energy generation from the onsite renewable energy system.
2. The next two largest energy end-uses include space heating and lighting, immediately followed by pumps, fans, space cooling, and domestic hot water.
From a building design perspective, enclosure heat loss performance and the efficiency of heating systems are of critical importance, as is the lighting design. However, the remaining energy end-uses were all significant to the low-magnitude annual target of 75 ekWh/m²—all analysis required careful attention to detail in the design.
3. To achieve a high-performance building, all systems must be synergistic.
The enclosure design, DOAS ventilation system, and low-energy lighting design combine to allow for low-intensity, low-energy heating and cooling plants. All investigated options achieved below 25 ekWh/m² a year.
It was clear that heat-pump-based solutions used significantly less energy than fossil fuel solutions. The design team’s early analysis included understanding the difference between modern air-source variable flow heat pump solutions and variable flow ground-source heat pump solutions. The differences were minor, but warranted detailed evaluation—suitable for this level of building energy performance.
Energy modelling sensitivity studies
To further clarify the energy performance design goals, a detailed hourly energy model of the building was created. This was used to perform sensitivity studies on occupancy- and demand-responsive systems, as well as receptacle loads and infiltration. It demonstrated the occupant load significantly impacted the building’s total energy consumption with respect to ventilation and receptacle loads. Sensitivity studies on receptacle load and infiltration also demonstrated significant impact on building energy consumption and focused the design team’s attention on these aspects of the building design and operation.
With the energy budget in place, a clear roadmap was established to inform each component of design, from the building’s orientation and material palette to the mechanical needs and photovoltaic (PV) targets. The latter of these informs what is intended to be the most iconic part of the Joyce Centre’s design—an onsite 545-kW photovoltaic array.
Net-zero performance and design strategies
By powering the building completely with electricity and generating the yearly total energy usage through its PV array, the Joyce Centre will generate onsite all the energy required to power its functioning throughout the course of the year.
The facility’s projected annual energy intensity is 70.5 kWh/m2 (approximated to within 2.5 per cent), which equates to an estimated annual consumption of 700,000 kWh (accounting for contingencies such as lab equipment, a targeted use of mechanical systems, and an allowance for unregulated plug loads). During the longer summer daylight hours, the solar system will provide more energy than the building requires with the sun high in the sky. During the shorter winter months, energy production will generally be less than the building needs.
The solar system will be optimized so on an annual basis, actual energy production will slightly exceed predicted energy consumption. Since the mechanical design of the facility is demand-operated, it will only run when the building is occupied.
Daylight and lighting systems
Daylighting elements include high-mounted daylighting fenestration above vision glazing in all laboratory and classroom spaces. While still providing diffuse light to the space, daylighting will incorporate glare-control elements.
Designed with the intent to harness daylighting as a primary source of illumination, the electric lighting system controls will reduce electric light output when adequate daylight is available. Lighting will be switched off by occupancy sensors should the occupant neglect to manually shut the lights off.
The mechanical systems are being designed for efficiency using the following guiding principles:
Water conservation and supply
Potable water use reduction is one of the key sustainability objectives of this design. Strategies that were employed include:
Taking a holistic approach to the building’s design, the windows, walls, and roofs were treated as a single system, with an overall effective heat loss performance target being assigned. This target required the architecture team to focus not only on wall insulation and window U-values, but also on the impact of glazing ratios on the whole-building-envelope heat loss. A very detailed analysis of the envelope assemblies ensued.
The high-performance, unitized, triple-glazed curtain wall assembly—specifically augmented for this project—will employ rubber isolation gaskets between unit frames to help ensure the lowest possible heat transmission. The system, among other innovative aspects, helps prevent flanking, which is when heat moves laterally between aluminum frames. Glazing units with multiple low-emissivity (low-e) coatings, ceramic frit, and argon fill will combine with a highly studied window-to-wall ratio to control solar loads and reduce cooling demand. (The ratio of vision glass to opaque wall element is an important index of the thermal efficiency of the total building envelope system.)
High-performance envelope design details
To increase the stability of the interior environment relative to the climate loads and ensure the HVAC systems work the minimal amount of time, the facility’s thermal performance has been designed to achieve an effective average value of approximately RSI 1.76 W/m2/C (R-10 Btu/sf/F).
The glazing is a unitized triple-glazed aluminum system, with specialized framing and gasketing. All vision glazing targeted a thermal performance of U-value 0.8 W/m2/C (R-7). In addition to the curtain wall, an insulated precast sandwich panel system was selected to assist the construction manager in accelerating the construction schedule. The panels have 100 mm (4 in.) of encapsulated polyisocyanurate (polyiso) insulation with 75-mm (3-in.) sprayed polyurethane foam (SPF) insulation backup. The system can be erected quickly, with excellent quality, and sealed from the interior for exceptional field value thermal performance.
Roofs are designed to a thermal performance of RSI 7.01 (R-40). The assembly is designed as a conventional system, comprising two-ply styrene-butadiene-styrene (SBS) modified bitumen (mod-bit) membrane, polyiso insulation board, and vapour barrier on a sloped structure with local tapered insulation board. The system will be cold-applied adhered, with a high-reflectivity top sheet.
Structural framing and special structural features
As fitting for Hamilton, the Steel Capital of Canada, the building superstructure will be structural steel. Floor composition will be 90 mm (3 ½ in.) of concrete on a 75-mm (3-in.) steel deck for a total depth of 165 mm (6 ½ in.). Steel beams will support the deck and concrete using composite action. The composite action and use of dead-load camber on the beams will minimize the depth of the beam required to carry the floor load and control deflection on the long spans. This will allow for maximum open space and future flexibility.
The solar PV support system will be a combination of structural steel and proprietary supports by the solar panel fabricator. To maximize the area of the solar collection, a unique design for the solar farm will span across the building in the east−west direction. The wing-shaped structures will be supported on a series of uniquely designed steel sections, which will be fully exposed to add a unique aspect and teaching potential.
Facilitating the understanding of the human/energy ecology
Mohawk College’s Joyce Centre for Partnership and Innovation will create a new paradigm for sustainable building and learning in North America. It underscores a cultural shift in design where occupant behaviour migrates from open, unrestricted energy consumption to personal accountability for carbon footprint.
The building will make users aware of the energy they are consuming and encourage them to consciously change their behaviour—such as charging laptops and mobile devices at home instead of constantly plugging them into the facility’s infrastructure. The emphasis on providing building performance feedback to the occupants builds a culture of awareness, whereby energy is no longer abstract. Through extensive systems metering and real-time data streaming analysis, they will have the ability to observe the temperature, humidity, ventilation rates, thermal distribution, lighting performance, and occupancy status, in addition to other key building performance metrics.
The building itself will also serve as a teaching tool. Students, through capstone or research projects, will have the opportunity to manage the operations of the building. They will learn first-hand the importance of operations and occupancy on building performance.
The net-zero-energy design of the Joyce Centre aligns with a new vision for the re-emerging city of Hamilton as an educational and healthcare hub. Innovative in its approach and iconic in its design, the facility both marks the beginning of a transformation for the region and bolsters the evolution of truly sustainable design.
|GREENER BUILDINGS AND GOVERNMENT SUPPORT|
|The project leadership behind Mohawk College’s Joyce Centre for Partnership and Innovation understands the importance of buildings with respect to the health of the atmosphere (e.g. greenhouse gas [GHG] emissions and air pollution), as well as the responsibility to push for positive change.
According to the World Green Building Council (WorldGBC) “2015/2016 Annual Report,” buildings account for more than 30 per cent of carbon dioxide (CO2) emissions and use about 14 per cent of the world’s potable water.* Considering the influence the built environment has on personal health and
As Canada continues to strategically position itself as a leader in sustainable building and construction, it is making a remarkable investment in its future. The Post-secondary Institutions Strategic Investment Fund (SIF) will see up to $2 billion invested in improving the quality and lifespan of Canada’s college and university buildings.† Along with the Canada Green Building Council’s (CaGBC’s) commitment to developing a net-zero verification program and support of the WorldGBC’s goals that all new buildings are constructed to be net-zero by 2030 and all buildings achieve net-zero by 2050, the country’s progressive stance on building solutions to mitigate climate change presents incredible opportunities for designers and architects to advance the culture of sustainable design.
* For more, visit www.worldgbc.org/sites/default/files/P578%20WGBC%20Annual%20Report_LR4.pdf.
** Visit www.cagbc.org/cagbcdocs/aboutcagbc/CaGBC_2016AR_ENG.pdf.
† Visit www.ic.gc.ca/eic/site/051.nsf/eng/home.
Kevin Stelzer, OAA, NLAA, MRAIC, BSSO, LEED AP, is a principal at B+H Architects, focusing on laboratory, retrofit/renewal, commercial, and educational building types across North America, the Middle East, and Asia. He studied architecture at the University of Waterloo and building science at the University of Toronto. A licensed architect and Building Science Specialist of Ontario (BSSO), Stelzer served on the Canada Green Building Council (CaGBC) Energy & Engineering Technical Advisory Group and on the United Nations (UN) Sustainable Buildings & Climate Initiative Task Force. He can be reached via e-mail at email@example.com.
Joanne McCallum, OAA, FRAIC, LEED AP, is the director and co-founder of mcCallumSather. For 21 years, she has provided direction, oversight, and mentoring, building a thriving integrated design firm in Hamilton. McCallum was an early pioneer of the integrated design process and national speaker on the topic of sustainable design, including recent presentations at the CaGBC National Conference. She can be reached at firstname.lastname@example.org.
Tony Cupido, PhD, is a broad-based engineering and operations senior professional with over 35 years of experience in facilities management and sustainability. He has considerable institutional experience, particularly with both Hamilton school districts, McMaster University, and now Mohawk College where he is chief building and facilities officer. Cupido has facilitated the planning, design, construction, and operation of building projects totalling $750 million. He has a doctorate in civil engineering with a focus on green buildings and policy and is a former adjunct faculty member at McMaster. Cupido can be reached via e-mail at email@example.com.
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