Mountain Equipment Co-op
The new Ottawa store for Mountain Equipment Co-op is the first retail building in Canada to comply with Canada's C2000 Green Building Standards. This standard relies on energy efficiency, minimal environmental impact, occupant health and comfort and functional performance as the major guiding factors. The building was designed using the C2000 integrated design team process. The 23,000 square foot store and warehouse is constructed from predominantly salvaged materials (or new materials with recycled content) and has been designed and built for future disassembly. It consumes 50% less energy than a similar building, builtto the current standards of the Model National Energy Code for Buildings.
- Structural and finishing materials were selected for low embodied energy, low toxicity, and minimal environmental impact.
- 50% of the materials, by weight, are used or from recycled sources.
- 80% of all materials have travelled from no more than 500 km. to the site.
- Panelized materials and primarily screwed connections have been specified in order to facilitate end-of-life-cycle disassembly of the building for re-use or recycling.
- A CO2 sensor for adjusting fresh air based on the occupancy level of the store.
- No CFC's and minimal HCFC's used in the manufacture of materials specified or in the operation of equipment.
- A demonstration straw bale infill wall complete with viewing portal.
- A large scale cistern to collect and store roof rainwater for the native species landscaping.
- Use of trees was maximised to shade the parking area.
- Low albedo gravel (white) is used in the parking lot to reduce solar heat gain and increase ground water recharge.
- A construction waste re-use and recycling management program was instituted.
- Disassembly and reuse of 75% of the materials, by weight, from the structure and shell of the existing 40 year old building which was present on the site.
- Maximum use of natural daylight through a roof monitor and skylights.
- Rock excavated from the site will be used for a portion of the cladding material.
- Energy consumption at 50% of MNECB
- Lighting load at 1.4 Watts/square foot. Less than 50% of MNECB
- Construction waste reduced by 75%
- 10% of electrical energy usage supplied by an alternative renewable energy source (wind turbine or photo voltaics)
- Building Type: Two storey retail store with a warehouse component
- Gross Floor Area: 2150 square metres
- Location: 366 Richmond Road, Ottawa, Ontario Completion: June 2000
- Owner: Mountain Equipment Co-op
- Construction Manager: Justice Construction
- Architect: Linda Chapman Architect & Christopher Simmonds Architect in Joint Venture
- Mechanical Engineer: Leslie Jones & Associates Inc.
- Electrical Engineer: Leslie Jones & Associates Inc.
- Energy Modelling: Leslie Jones & Associates Inc.
- Structural Engineer: Cleland Jardine Engineering Limited
- C2000 Facilitator: Enermodal Engineering
- Landscape Architect: Jim Lennox
- Cost: $2.8 million CDN
The new Ottawa store for Mountain Equipment Co-op is the first retail building in Canada to comply with Canada's C2000 Green Building Standard. This standard relies on energy efficiency, minimal environmental impact, occupant health and comfort and functional performance as the major guiding factors. The building was designed using the C2000 integrated design team process.
Mountain Equipment Co-op is a strong advocate of environmental preservation and restoration. They are very intent on proving their commitment to the environment by developing green buildings. In tandem with the C2000 criteria the owners also wished to pursue a "Gold" rating from the U.S.Green Building Council's LEED Green Building Rating System. LEED stands for Leadership in Energy and Environmental Design.
Site Design & Context
Mountain Equipment Co-op (MEC) had purchased a 40 year old 1,000 square metre building on Richmond Road in the Westborough area of Ottawa. They had also purchased 2 additional properties adjacent to this building in order to supply the city's parking requirements for a large retail structure. The program was to provide a 2200 square metre retail store of which 2/3 is retail space and 1/3 office/warehouse space. The design team decided that renovating the existing structure and incorporating it into a new building would entail structural and energy efficiency compromises. The team opted to have it disassembled and many parts reused or recycled.
The form is a simple square two storey building. This shape was chosen instead of a long and larger one storey form in order to reduce the total amount of land required for the building and parking. A cubic form was also seen as the most optimal shape for MEC's merchandising layout and for overall energy efficiency.
The modest urban site is required to carry 62 parking spaces and 2 loading bay areas, leaving only a small amount for landscaping. Nevertheless perimeter and street tree planting is extensive in order to maximise the shading of paved areas. Existing clumps of Manitoba maples were retained on the site. A native species planting space is provided along the west side of the building including a rain water cistern for watering and trellises for perennial vines to shade the south and west facing windows. Local boulders and recycled sidewalk slabs are also featured. The parking lot is paved with light coloured crushed stone in order to reduce water run-off and reflect excess heat.
Building Envelope and Structural design
The structural frame of the building is made mostly from salvaged materials. Salvaged materials have been chosen over new wherever possible for their low embodied energy and in order to reduce landfill usage. The ground floor timber frame is made of Douglas fir posts and beams, salvaged from old log booms in the St. Lawrence river. The roof and supporting structure uses all of the old steel posts, beams and joists from the original building. Approximately half of the roof joists had to come from new steel. The grid lines and column locations follow that of the existing building in order to facilitate foundation, column and beam reuse. The 2 hour fire rated party wall on the east side of the building was rebuilt entirely with recycled concrete blocks and steel posts from the old structure.
The building envelope is made from engineered wood products. 9 -1/4 inch deep engineered wood truss joists are used as balloon frame walls all around the perimeter of the structure. The joist-studs are filled with cellulose insulation, providing a value of R30. This system was chosen because of low embodied energy, high insulation value, use of renewable resources, use of materials with low toxicity (ie. no urea fomaldehyde), and the ease of future disassembly. The joist-studs are clad with salvaged plywood sheathing with self-adhesive elastomeric air barrier strips taping the joints. Wall cladding varies for aesthetic interest. Corrugated steel panels were chosen for durability. Fibre cement boards were chosen for areas where vines would grow.
The building foundations are shallow and sit on bedrock. The existing concrete slab and terrazzo floor finish has been retained and a new concrete floor poured beside it for the additional area. There is no insulation underthe slab but R 16 perimeter insulation (semi-rigid rockwool) has been installed around all new and existing foundation walls.
All storefront windows are clear anodised thermally broken aluminium framed systems. The concession was made towards the choice of a high embodied energy material (aluminum versus fiberglass) because of high traffic and maintenance issues. All north facing windows are triple glazed, low e, argon filled with warm edge spacers (R-7.3).
All other windows are double glazed (R-4). Office and warehouse windows are wood with extruded aluminium cladding (R-4). All windows are fixed except for 50% of the office area windows. Skylights are double glazed, low e, argon filled built on insulated curbs (R3.2).
The flat steel roof deck is screw fastened and insulated with 10 inches of high density rockwool insulation (R-40). The building envelope is airtightand has insulation values 4 times the MNECB required levels.
Heating and Cooling
Natural gas fuels all the energy efficient air handling systems used to condition the building. The building zones include the following areas:
- Upper Retail
- Lower Retail
- Warehouse area
- Office Area
- Front Entrance
All of the spaces will be fully heated and cooled with the exception of the front vestibule and stairwells, which will be heated only. The HVAC units will consist of a central high efficiency condensing boiler serving coils in the air handling units. All the air handling units will be mounted on the roof. A VAV system will serve the office area. Hot water radiators will provide heat to the stairwells and shipping area.
A direct vented pulse combustion boiler is proposed with outdoor air reset of supply water temperature. At part load, with a lower supply and return water temperature, the boiler efficiency increases up to 95%.
The custom rooftop heating sections have high efficiency power burners with modulating combustion air and a 15:1 turndown. The efficiency rises to over 86% at 20% part load and dropping back to 85.5% at 10% part load. Dx cooling is provided by multiple hermetic scroll compressors utilising R-407C refrigerant which is non-ozone depleting. Motors are extra high efficiency. A differential enthalpy economiser is provided. Space cooling set point is raised with ambient temperature to minimise indoor-outdoor temperature differential. Thermally insulated low leakage dampers are included on all custom HVAC systems. The HVAC is fitted up with economisers for free cooling.
Ventilation and Air Quality
There is a variable ventilation rate based on occupant load. CO2 monitoring will reset minimum position on outdoor air handling units. Thermally insulated low leakage dampers with blade and edged seals are provided on outdoor air dampers. Meeting rooms have controls to increase ventilation when the space is heavily occupied. An enthalpy type heat wheel (Venmar ERV 500) provides heat recovery on ventilation. Continuous exhaust exits from the washrooms and preconditioned outdoor air is returned to the general merchandising area. Operation is sequenced with store operating hours by an EMCS.
Lighting and Daylight
Daylighting was considered a desirable feature to enhance the retail space but should not cause glare. The experience in MEC's previous store was that a central skylight and atrium was effective in providing natural light on the climbing wall and tent displays. Clerestory windows in walls were avoided because they tended to cause high contrast in the clothing areas.
The decision was made to minimize windows overall, particularly on the north facade and concentrate them on special public areas within the store. The large atrium and roof monitor introduce ambient daylight onto both floors of the building. All south and west windows have louvered horizontal sun shades arranged to permit winter sun and block out summer sun. Curb mounted skylights over the warehouse area have 50% coverage shade cloths installed outside over the windows in the summer. All staff areas have manually operated 50% coverage solar reflecting interior shades for additional summer shading. Most windows are fixed, less than 10% are operable.
Lighting power density (power allowance) is 14.59 W/m2, less than 50% of MNECB. The majority of display lighting is T8 fluorescent with low mercury, high lumens and custom spectral reflectors. All fixtures use electronic ballasts. Accent display lighting is a mix of energy efficient metal halide and compact fluorescents with limited use of tungsten halogen, for display colour rendition. Washroom and warehouse lights are switched on by occupancy sensors. Lights are kept off when daylighting is adequate in daylight areas of store. EMCS schedules lighting with store staffing and opening schedules. Display lighting is on a separate schedule from general store lighting.
Plumbing and Water Heating
Hot water for washroom and staff showers is supplied by a 94% efficient natural gas hot water heater. Low flow shower heads are provided in the showers. Filtered and non- cooled water is available at the water fountains. Sensor activated lavatory faucets have pressure regulating valves to maintain low flows. A waterless urinal is specified. Power assisted low flow water closets are in use in all washrooms. Rain water is collected for plant irrigation. Water consumption is estimated to be 30% below MNECB.
Finishes and Furnishings
Interior finishes have been selected on the basis of simplicity, low mainentance, minimal environmental impact, high durability and low VOC emissions. Interior finish treatments have been minimized by leaving the structural members and concrete block walls exposed wherever possible. The ground floor uses the existing terrazzo floor and new ground floor areas are coloured concrete. The second floor is a structural wood deck made from salvaged douglas fir. Wet areas have sheet linoleum floor product. Westroc EcoLogo gypsum board products clad walls which have a finish treatment.
VOC free adhesives and Ecologo paints are used throughout. The interior retail fit up is composed of fabric or photographic panels on movable Unistrut members. This allows for maximum flexability and expansion/contraction between the retail and back stock areas. It also reduces the quantity of building materials required for interior partitions. Typical store millwork uses birch or maple veneered and sealed plywood. MEC management intends to relocate many of the fit up items from the old store into the new store. Office and staff rooms will be furnished with quality used or recovered furniture wherever possible.
Equipment and Appliances
MEC has chosen to use super high efficiency appliances. This includes a high speed spin, non vented (condensing) clothes dryer, an electric cooktop, built-in dishwasher, and low water consumption tumble action washer with integral water heater. A 20 KW Wind turbine power generator is proposed for the site and will be installed only upon community approval.
Mountain Equipment Co-op Store
Wood Le Bois, Spring 2001
International Design Magazine, February 2001
Designing for Disassembly
Canadian Architect, January 2001
The Ottawa Citizen, September 2, 2000
MEC makes 'hay' with 'greenprint'
The Ottawa Citizen, October 16, 1999