TOHU, Green Building

In order to adhere to the Land component of its mission, TOHU could not be content with being a performance hall like any other: its building also had to meet the highest environmental requirements.

When it opened in 2004, it was the first LEED-Gold Canada certified green building in Quebec. This program (Leadership in Energy and Environmental Design) imposes the strictest environmental standards and criteria, both during the construction and management of a building.

Entering TOHU is therefore entering a world where environmental concerns permeate every space, every experience. Here are some of its distinctive features.

PASSIVE GEOTHERMAL ENERGY

To regulate the Pavilion indoor temperature, TOHU uses passive geothermal energy, which involves introducing outside air underground, at a depth of two meters into an underground duct, then allowing it to enter the building. TOHU’s geothermal wells are 60 meters long. This distance allows the air to be pre-heated or pre-cooled by more or less 7 degrees Celsius, depending on the season.

CONVENTIONAL GEOTHERMAL ENERGY

In 2007, five geothermal wells were dug on the TOHU site. At a depth of 325 feet, where the temperature stabilizes year-round between 9 and 21 degrees Celsius, these wells provide very low geothermal energy. Their use is quite simple: the temperature underground is different from that at the surface, it is therefore a question of extracting heat from the ground to use it as heating (in winter) or, on the contrary, injecting the excess heat underground for cooling (in summer). At TOHU, the wells are thus used for heating and cooling the administrative building.

BIOGAZ HEATING

One of the main applications of the concepts of sustainable development, valorization and circular economy lies in the partnership with the Biomont power station, located just across the street.

It captures the biogas from waste residues from the Saint-Michel Environmental Complex (the former municipal dump that became Frédéric-Back Park; the large white spheres that you see while walking through the site are all checkpoints for the pressure linked to the collection wells) and converts it into electricity, via three internal combustion engines coupled to three generators with a power of 1.6MW each. This electricity is then sold to Hydro-Québec Distribution.

The residual heat produced by the engines during the process is transferred to the water, which is then used for heating the nearby TOHU and Cirque du Soleil facilities. There are still large amounts of excess heat and several projects are under consideration, including an urban greenhouse. The pipes that lead to TOHU also allow heating of the concrete slab covering the main public entrance since 2018, keeping it safe at all times, even in winter.

NATURAL AND HYBRID VENTILATION

This concept uses the chimney effect of the 23-meter-high performance hall to evacuate hot air. It consumes 70% less energy than traditional ventilation systems. The air in the hall heats up gradually and, since hot air is lighter than cold air, it rises to the top of the hall by a so-called chimney effect. When the outside temperature allows it, TOHU thus benefits from a very low velocity natural ventilation system, that is therefore very energy efficient, to supply the performance hall.

RECYCLED ARCHOTECTURAL ELEMENTS

The grand staircase balustrade handrails come from the La Ronde bumper cars. Recycled beams from Angus factories were also integrated into the Pavilion structure. The railway sleepers (CN) were also cleaned and decontaminated to build the entrance. Finally, TOHU's exterior cladding is made of fiber cement (cement and sawdust). Highlighted at TOHU, these elements symbolize the city’s industrial heritage. Some bicycle parking terminals are also made from old recycled spokes.

GREEN ROOFS

Since 2006, three plant surfaces cover the roofs of the ground floor offices, public washrooms and TOHU’s northern entrance.

The system currently in use consists of a drainage panel, an anti-root membrane and a mixture of soil, fertilizer and other organic substances. The selected plants require minimal maintenance. In addition to absorbing and managing rainwater, such roofs reduce temperature variations as well as cooling and heating loads.

They help reduce heat islands in urban areas and also protect the roof membrane from ultraviolet rays, thus increasing its lifespan.

NATURALIZED BASIN

The naturalized basin along the administrative building collects rainwater from the roofs using a geotextile membrane and a layer of clay that retains water.

Eventually, this water dissipates by evaporation or percolation into the soil. The basin allows the retention of rainwater, which avoids clogging the City of Montreal’s storm sewer system, while feeding the marsh’s aquatic plants.

GARDENS

The TOHU vegetable garden, in addition to providing quality organic vegetables, brings awareness of urban agriculture. One of the three plots is loaned to the Carrefour populaire Saint-Michel to serve as a community garden and educational tool. The other two, managed by urban agriculture organizations, are available to the Bistro, which uses its seasonal herbs and vegetables, as well as TOHU employees. On the remaining land, all vegetation is native, and the use of sod is minimal.

BEEHIVES

Thanks to a collaboration with Miel Montréal, TOHU joins the ranks of 45 Montreal institutions that host a beehive. This project allows bees, which are currently a precarious species in many regions of the world, to pollinate freely on the Saint-Michel Environmental Complex.

The two hives bring together between 80,000 and 140,000 bees. The next time you visit TOHU, purchase our honey on sale at the bistro!

TOHU has also set up a honey trail near the beehives. The latter, designed and produced in partnership with Miel Montréal, is an example of an intervention favorable to biodiversity. What was before a lawn is now home to several native and honey species, which attract many pollinating insects every summer! The general public can visit the TOHU apiaries independently or during a guided tour through the pollinator trail.