Ok, we are late to this party: the Mountain Equipment Co-op headquarters in Vancouver won the Canadian Wood Council’s Wood Design Award- in 2015. I can only think that the reason we didn’t cover it last year was because it didn’t look much different than a hundred other wood buildings built a hundred years ago out west- mill decking on beams on columns. Meanwhile, we were seduced by Tall Wood and sexy high-tech Cross Laminated Timber (CLT), and what’s really new here?
Whats new is what’s old. Proscenium Architecture, working with engineers Fast + Epp (engineers for the UBC wood tower too), are using technology that much of west coast industrial and commercial buildings were built with for 150 years. Mill decking, now known as Nail Laminated Timber (NLT) is not nearly as sexy as CLT; it’s basically just banging lumber together, but it is well known to engineers and building inspectors, can be done by anyone, and not limited to the one or two suppliers of CLT. The MEC building is the biggest example of a new wave of old tech that we will be seeing a lot more of.
It was not their first choice. As the Wood Works! case study notes, MEC and the architects wanted sexy new CLT too.
With the desire for simplicity, economy and flexibility, a glulam post and beam system was chosen for the primary structure, with the floors being constructed using mass timber panels. While the initial preferred option was to use CLT panels for the floors, the building was designed in such a way that permitted nail-laminated timber (NLT) panels to be carried forward as an alternate at the time of tender.
There were issues of detailing, fire resistance and moisture protection that arise when using NLT instead of CLT but when the project was tendered, NLT proved more economical. Furthermore, if you are designing with traditional posts and beams, NLT actually makes more sense; CLT has different structural properties that are redundant when you have Structurlam’s lovely Glulam beams to sit on.
Whenever one builds with wood, the question of fire protection comes up. The floors here are built up out of 2x8 Douglas Fir, engineered to have a sacrificial charring layer. There are also sprinklers throughout.
There is a lot of other interesting stuff going on in this building:
The building is heated and cooled through a series of 20 geothermal wells optimized by a ground-source heat pump system. Geothermal heat pumps are located between two large thermal storage reservoirs, limiting the number of heat pumps required and reducing electrical use. Heat pumps operate during off-peak hours to cool the reservoirs, and during the day, when demand peaks, the extra energy stored in the reservoirs is transferred to the building.
When hot weather occurs, or is forecast, the wind towers go into operation to cool down the building or pre-cool it in preparation for the next day. The wind towers take in fresh air from the roof inlets, directing it through fans into raised floor plenums on the main levels of the structure. Air from the ceiling level is exhausted outside. During mild conditions, air is re-circulated and heated or cooled using coils in the base of the wind towers.
But the really exciting feature for this TreeHugger is the trees. As Wood Works! concludes:
The MEC Head Office building 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 structure, with floors of solid nail-laminated dimension lumber and a non- loadbearing exterior skin – most often of masonry.
They also note that this is lower tech than our beloved CLT but can make a lot of sense:
The success of this project has demonstrated that solid wood systems for commercial buildings are a viable and desirable alternative to other forms of construction. The structural system used for MEC is highly replicable, as it does not require high-tech mass timber panel products, but can be successfully undertaken in any well-organized prefabrication shop.
Heck, you can do it on site with a couple of workers with nail guns. In a world where we want to build with renewable resources like wood, it doesn’t all have to be high tech; sometimes the old ways work just as well or better, and do the same job.