Project Specs

Location: Toronto, Ontario
Climate Zone: Cool-Temperate
Building Type: Institutional
Certification Type: Passive House Classic
Year of Construction: 2019
Gross Floor Area (m2): 3247
Treated Floor Area (m2): 3247
PHPP Verification: Download

Project Description

Humber College’s Building NX has transformed from one of the campus’ most inefficient buildings to an industry-leading example on how to perform a deep energy retrofit.

Originally targeting EnerPHit certification for retrofits, the final project design was able to meet the rigorous requirements of the Passive House standard and has been certified as such.

Driven by the College’s commitment to providing national leadership in developing sustainable campuses, an extensive retrofit for Building NX, originally built in 1989, was performed which addressed both the building envelope and upgrades to major core building systems. The innovative methods and environmental technologies include:

  • High-performance building skin and engineered transitions for superior air control to alleviate thermal bridging
  • Newly installed Passive House Certified windows
  • Air-Source Variable Refrigerant Flow system which recovers and transfers heat between zones
  • Dedicated Outdoor Air System with Ventilation Heat Recovery
  • 24 kW Rooftop Photovoltaic Array
  • LED lighting fixtures and a networked lighting control system featuring occupancy control and daylight harvesting

Guided by Humber College’s 20-year Integrated Energy Master Plan, building NX will see a 70% reduction in energy use and over 90% reduction greenhouse gas emissions. Building Nx is also the first retrofit project in Canada to achieve the Zero Carbon (ZCB) Design Certification from the Canada Green Building Council.

Today, Building NX is the most energy efficient building at the College and one of the most energy efficient buildings in Canada. The project emphasizes the critical importance of existing building retrofits in the fight against climate change. A 2009 report by the UN indicates that the existing building stock represents the most important opportunity to substantially cut GHG emissions however there are some challenges. Building owners often shy away from major renovations due to costs and disruption. Part of the motivation for the NX project was to provide an example to the Canadian design and construction industry on how to perform deep, net-zero ready, energy efficiency retrofits in Ontario’s climate and to encourage similar projects in the future.

Thermal Envelope

Exterior Wall: Use of 8" mineral wool insulation with thermal clips behind metal cladding system. In addition, 4" of spray foam insulation within the interior structural stud wall. Fully integrated air vapour barrier is combined with the spray foam insulation to maximize air tightness.
U-value = 0.137 W/(m2K)
Basement Floor/Floor Slab: Due to the nature of the retrofit, floor slab is uninsulated.
U-value = 3.749 W/(m2K)
Roof: 11" of XPS is sandwiched between the roofing membrane and air vapour barrier, all of which sits on top of a structural concrete slab.
U-value = 0.103 W/(m2K)
Window: Triple glazed, argon filled.
U g-value = 0.68 W/(m2K)
g -value = 22 %

Mechanical System

Ventilation: Swegon, Gold RX 35
Balanced ventilation with heat recovery for supply and extract air.
Centralised ventilation system
Heating/Cooling: VRF heat recovery heat pumps serving individual fan coil units installed in each thermal zone. Vestibules use electric radiant in-floor system.
Domestic Hot Water: Instantaneous electric domestic water heater is located on the ground floor and serves all washrooms using a pipe circulation system.