By Liz MacKenzie
There are many people in Lowertown who came to love the Union du Canada building, a modernist structure with some brutalist elements, a style finally recognized for its important place in architectural history. Its butterfly windows and integral artwork set it apart from anything in the city, but there were powerful forces that wanted to redevelop that corner of Dalhousie and York. A threat of demolition certainly sharpens the mind, and the community worked tirelessly to save it, but in the end we made a deal with the devil: we traded height for history, and down it came. During the demolition it wasn’t unusual to run into fellow fanciers at the demolition site, paying their respects as the building was slowly destroyed.
As caravans of trucks took the rubble away, one had to wonder where this broken building was going. And beyond mere musing, a more important question: what have we lost in embodied energy in these materials and what is the environmental impact of the demolition?
Under an Access to Information request, I received more than 400 pages of documents filed by Priestly Demolition and the developer, Claridge Homes. Waste-audit reports were included detailing material removed from the site from August, 2013 to May, 2014, including date, carrier, receiver, waste type and weight of the load. Some of the invoices included details about travel time, wait time, and driver’s name. There is a lot of mining to be done with this data.
One of the easiest tasks was to calculate the total waste generated, types of waste and total distance travelled to the 14 disposal sites. Working out the transportation footprint was relatively simple when three variables were confirmed: class of truck, fuel efficiency, total km travelled and associated CO2 emissions.
Most trucks were class 7 or 8 type trucks and the fuel efficiency of this class in Ontario is 2.23 km/l ; total kilometres travelled from 325 Dalhousie Street to various sites and back: 60690 km; emissions per litre of gas 2.28 kilograms of carbon dioxide plus 0.30 kilograms production cost/litre to go from “well to wheel”.
Here’s the calculation:
Total Distance/ km/l: 60690/2.23= 27,191 litres of gas used
Kilograms of carbon dioxide produced: 27,191×2.58 =70,198
Recycling equivalents
- Every tonne of paper recycled can save the energy equivalent of 566 litres of gasoline.
- Fifteen trees can absorb a total of 100 kilograms of carbon dioxide from the air each year.
- Recycling one aluminum can saves the equivalent of 1.9 litres of gasoline.
Conversions into metric from https://www.recyclingbin.com/Recycling-Facts
So to offset the CO2 emissions of running a Class7 truck the equivalent of the distance from Victoria to Halifax14 times or around the world one-and-a-half times, and producing 70,198 kg of CO2, we would have to:
Plant 10,025 trees, recycle 14,333 aluminum cans or recycle 48 tonnes of paper.
Or we can just stop demolishing buildings. The renovation and renewal trades add more to the economy than the construction trade. Repurposing existing buildings retains neighbourhood identity and harvests their embodied energy. Our landfills, with their problems of seepage, groundwater, odour and overuse could be stabilized. It is the City of Ottawa that approves demolitions without a thought to the construction and renovation disposal issues. It’s time the provincial regulations, last updated in 1994, move into the 21st century, strengthen reporting and pass some responsibility on to the municipalities. Other municipalities have taken this on – why not Ottawa.