Mountain Equipment Coop

Mountain Equipment Co-op (MEC) is one of Canada’s most progressive retailers, having embraced a philosophy of corporate, social and environmental responsibility since its inception in 1971. With each new building project it undertakes, MEC endeavors to advance its sustainability agenda. In this respect, wood has played an important role: a reclaimed wood structure for its store in Ottawa, ON; a demountable post and beam frame for its store in Burlington, ON; and now an exposed heavy timber structure for its new four-storey 130,000-sq.ft. head office in Vancouver, BC.
Completed in the fall of 2014, the facility is home to all MEC’s head office functions, accommodating a staff of 375. The plan consists of two intersecting wings, oriented to optimize daylight and natural ventilation. The narrow floor plates are organized so that enclosed offices and service rooms are in the centre and open plan offices close to exterior walls and windows.

The arms of the plan intersect at the atrium, the social focus of the building where employees can meet, and the activities on one floor can be seen and heard from another. This feature is just one of many in the building that demonstrate MEC’s commitment to the well-being of its staff. This commitment also influenced the choice of wood for the structure, which creates warm and welcoming interior spaces that could not have been realized using any other material.

With the desire for simplicity, economy and flexibility, a glulam post and beam system was chosen for the primary structure and mass timber panels were specified for the floors. The preferred option was to use crosslaminated timber (CLT) panels for the floors, but to design in such a way as to permit nail-laminated timber (NLT) panels to be carried forward as an alternate. At the time of tender, NLT proved to be the more economical choice.

To limit the cross-grain shrinkage that can be a challenge in a building of this height, the structure was designed with single storey-height glulam posts, placed one on top of the other with end-grain-to-end-grain bearing. A combination plate and saddle connection secures the base of one post to the top of the next and provides bearing plates for the beams that run either side. The plates are secured to the top of each column with wood screws. Rebar dowels above the plate are epoxy-grouted into holes drilled into the bottom of each post. Each main bay of the building is 60 feet wide and is divided into three equal sub-bays of 20 feet. Thus, there are four lines of glulam columns connected by three sets of paired glulam beams in each main bay. The NLT panels are four feet wide and 40 feet long so that they span two sub-bays of the building. To facilitate diaphragm action, the panels are laid in an overlapping pattern to minimize continuous joints. Plywood sheathing is similarly laid across two adjacent panels in a staggered configuration, again to facilitate diaphragm action.

The heavy timber post, beam and panel structure provides a minimum one-hour fire-resistance rating. The former MEC Head Office offers us a glimpse into the past and the future simultaneously. In the 19th and early 20th centuries a significant proportion of Canada’s commercial buildings were constructed using a heavy timber post and beam frame structure, with floors of solid nail-laminated dimension lumber. This system was chosen for its economy, strength and durability, and many examples (including the ninestorey Landing building in Vancouver, BC) can still be found.
Today, wood structures continue to deliver on the promises of the past, but now our understanding of wood has broadened to include its benefits to environmental sustainability and human health. These contemporary concerns are central to the corporate philosophy of Mountain Equipment Co-op, which has demonstrated its commitment to environmental stewardship for more than 40 years, and whose concern for employee well-being is recognized. Its new head office may well prove to be a prototype for a new generation of commercial buildings.