Rooftop Solar PV System
The rooftop of the rear addition incorporates a photovoltaic (PV) array, designed to harness solar energy. The size of the system is 15.8kW and will generate about 19,000 kWh/year.
As it pertains to the overall site, the building makes use of the existing city infrastructure and proximity to local services such as a variety of shops and restaurants, and mass transit system. The building includes electric charging stations, bike storage and permeable pavers to retain water runoff. The landscape materials were chosen to stress high-albedo surfaces, which reflect much of the solar radiation, assisting in reducing the urban heat island effect.
All plumbing fixtures use low-flow rates to reduce water usage. When compared to the average building, the proposed will consume 40% less water.
Materials and products were chosen using an environmental analysis selection method, which analyzes their embodied carbon footprint, durability, installation ease and maintenance.
The mechanical system is designed to produce a high level of indoor air quality, which includes a UV air filtration system, an energy recovery ventilator, and an independent parking garage exhaust. Moreover, all finishes and paints for the interior were selected to have low to no levels of VOC, and the natural daylight optimization improves environment quality.
Low Energy Usage
The building is projected to require approximately 300,000 kWh/year to operate, which translates to 130 kWh per square metre per year. This is very close to the Passivehouse standard of 120 kWh/sm/year, which would result in approximately 288,000 kWh/year energy usage.
All door and window openings are designed with thermally broken and insulated systems that will achieve an average thermal performance of 1.47 W/m2K U-value. Compared to an average building, the proposed openings thermally perform 1.4x better.
The building enclosure is designed with large high-performance window, door and skylight openings. As such, natural daylighting is being used to reduce the amount of artificial lighting, which reduces the overall energy demand.
The building enclosure is designed to a very high-performance level. The wall and roof enclosure are designed with continuous insulation throughout, and structural connections include thermal breaks, in order to eliminate thermal bridging.Walls are designed to have an average insulative value of R-44, and roofs an average of R-57.5. Compared to an average building, the walls and roofs thermally perform 1.5x better.
The building enclosure is designed with continuous high-durability air barriers throughout, which minimizes the amount of air leakage. The designed target air leakage rate is 1.0 ACH50, which meets the Passivehaus EnerPHit high standard for renovation projects.
The building incorporates an authentic heritage restoration of the historic 1900s original building, carrying it forward as part of the larger context of the midtown Toronto community.
Mass Timber Structural System
The new rear addition is constructed in a mass timber structural system, incorporating cross-laminated timber (CLT) floor and wall panels, and glulam columns. The wood in the mass timber elements came from trees which sequester carbon from the atmosphere. Structural materials like concrete and steel require large amounts of embodied carbon to create them. The carbon footprint of mass timber elements is far lower than that of steel or concrete equivalents. From its raw extraction to the building erection, the use of each cubic metre of mass timber releases about 85kg CO2 into the atmosphere (not including sequestered carbon by the trees). The average cubic metre of concrete releases about 350 kg CO2, and steel about 900 kg CO2.
The addition is designed for flexibility, including the expansion of an additional 4-storeys (8-storeys total). This future expansion is designed into all structural, civil, mechanical, electrical and plumbing systems.
April to July, 2022:
Shoring and pile drilling
Excavation and lagging
Expect significant road disruptions as materials enter and exit the site.