The Mountain Equipment Co-op (MEC) store in Montréal is the company's eighth retail store and the third (after stores in Ottawa and Winnipeg) to comply with Natural Resources Canada's (NRCan) C2000 Green Building Standard. It is the first C2000-compliant retail building in Quebec and was one of three projects that represented Canada at the international Sustainable Building Conference in Tokyo in 2005.
Project And Challenges
The new MEC store is located in a big-box shopping complex at the intersection of autoroutes 15 and the Metropolitain in Montréal. The building volume, site planning and land agreement had to meet the requirements of both tenant (MEC) and landlord (Fiducie Immobilière MCM).
The challenge for the team was to integrate the MEC store concept and the program's environmental objectives with commercial big-box retailing realities. This provided a unique opportunity to apply sustainable development goals to the big-box retail model in Quebec.
The project team used an integrated design process to meet strict environmental objectives. The thermal mass properties of concrete made it an excellent material to use in the building's radiant heating and cooling strategies. Concrete contributes to MEC's saving of about 50 percent on energy costs compared with conventional retail buildings. Concrete was also appealing as a durable material that could be left exposed.
Concrete Products Used For This Project
- The concrete used in this project was Lafarge's ternary composite cement, Tercem 3000TM, which shows the same setting behaviour as concrete produced with TypeGU cement made from the same Portland cement clinker.
- Silica fume used in the MEC concrete comes from the condensation of SiO vapour produced in an electric arc furnace during the production of silicon metal and ferrosilicon alloys. It complies with the requirements of CSA A3000-98 A23.5 Supplementary Cementing Materials for a Type SF material.
- Slag used originates from blast furnaces used to manufacture iron and complies with the requirements of CSA A3000-98 A23.5 Supplementary Cementing Materials for a Type S material. To make the product suitable for use in concrete, the molten slag is rapidly cooled by pelletization prior to intergrinding. This produces a glassy (amorphous) material that is predominantly composed of silicates and alumino-silicates of calcium (and to a lesser extent magnesium). Ground granulated (iron) blast furnace slag is a latent hydraulic material that produces hydrates similar to Portland cement. Slag can improve many of the properties of concrete by improving long-term strength and durability.
Reasons Concrete Was Selected For This Project
Concrete was selected for its thermal mass properties, its durability and its aesthetic qualities.
The heating/cooling system was decoupled from the ventilation system to avoid over-sizing the systems. Heating and cooling is provided through hydronic radiant concrete slabs. PEX tubing is embedded in the slabs and a water-glycol mixture circulates through closed loop system. The concrete slabs act as a thermal mass to stores heat energy and release it slowly to the space. The main energy source is a geothermal system consisting of 12 wells drilled 175-metres deep and coupled with eight liquid-to-liquid R-407c energy efficient heat pumps. This system transfers heat from the ground into the concrete slabs in winter and rejects heat into the ground in summer to cool the building.
The building systems are fully automated. Temperature controls connected to the Internet automatically retrieve weather forecasts for the next day and night. The forecasts and simple predictive logic prompts the system to pre-heat or pre-cool the slab to offset temperature extremes. Predicting temperatures allows nighttime energy storage and limits the heat pump's daytime electrical demand.
Contributes To The Aesthetics Of MEC
All the concrete elements were left exposed and define the material aesthetic of the building interior. There was no noticeable difference in the colour of the slag concrete. The walls of the elevator shaft were formed with boards for added texture and plastic form liners were used for the freestanding round columns to give them a polished, granite-like sheen. The building has received many favourable reviews from the media and customers for its pleasing aesthetics, environmental features and attention to detail.
Meets sustainable design and construction objectives
Natural Resources Canada indicated that the MEC store was the most energy efficient building in Quebec when it was built, according to submissions received under their Commercial Building Incentive Program (CBIP) for New Buildings. Energy modelling software calculated a yearly energy cost saving of more than $100,000, which limits the payback period for sustainable design strategies to 4.3 years.
The project team used concrete as one of the main structural elements because of the radiant slab strategy and because it can be left exposed as the final finish material. The challenge was to reduce the greenhouse gas emissions associated with the Portland cement used in concrete. Given that cement manufacturing accounts for 7-8 percent of global CO2 and about 2.8 percent of Canada's CO2 emissions, the MEC project team replaced 27 percent of the cement of a standard mix with blast furnace slag and silica fumes. Therefore, the project prevented 152 tonnes of CO2 emissions into the atmosphere. Prior to the MEC project, SCM concrete was relatively unknown and underused in Quebec due mostly to the lack of locally produced blast-furnace slag and fly-ash. Due in part to research into locally available SCMs and MEC's high-visibility project, the situation is improving. The project was used as a case study by EcoSmart to highlight the use of SCM concrete in Quebec.
Awards And Distinctions Won To Date
SB05: Selected to represent Canada at Tokyo
ASHRAE Technology Award (building category and award for engineering excellence)
Canada Energy Efficiency Award Honourable mention
Energy Efficiency Forum of the Island of Montreal (winner for energy initiatives)
Commerce Design Montreal Grand Jury Prize winner Canadian Institute of Steel Construction, Honourable mention (green building category)
AQME Green building award
Contech Sustainable Development Trophy
C2000: First C2000 compliant commercial building in Quebec
|Client / Tenant||Mountain Equipment Co-op|
|Architect||MTF Architects (Studio MMA, Atelier d'architecture Lyse M. Tremblay, architect Duschenes & Fish, architects)|
|Construction Manager||Broccolini Construction Inc.|
|Civil Engineer||Vinci Consultants|
|Structural Engineer||Saia Deslauriers Kadanoff Leconte Brisebois Blais|
|Mechanical, Electrical and Energy Engineering
||Pageau Morel and Associates Inc.|
|Landscape Architects||Williams Asselin Ackaoui and Associates Inc|
|Waste Management||Jacques Whitford Environment Limited|
| Cement Supplier
|Structural Concrete Placer||Coffrage Multiformes Inc|
|Concrete Finisher||(Also placer of slab on grade) ACF|
|Site Concrete Placer||Pavage Maska|