Nova Scotia Power’s new head office building, 1H, has achieved LEED Platinum certification, the highest green building rating and the first building in the Maritimes to achieve this designation from the Canada Green Building Council. Nova Scotia Power, a provincial utility, commissioned WZMH Architects and Enermodal Engineering, a member of MMM Group, to renovate their defunct former coal-fired generating station on Lower Water Street in downtown Halifax into a LEED Platinum office building for approximately 600 employees with a site that would encourage community interaction along the city’s waterfront.
“Nova Scotia Power’s new headquarters is one of those rare projects that transforms the local community and raises the bar for green building design for the entire building industry,” says Jon Douglas of Enermodal Engineering, the LEED, energy efficiency, measurement & verification, and green building education consultant on the project.
“Achieving the LEED Platinum designation for our office building in Halifax is an important milestone, not just for our company, but also our community and our city. We look forward to making a positive contribution to our neighbourhood and the environment,” said Paul Currie, Nova Scotia Power’s Senior Project Manager for this construction project.
Focusing on Energy Savings
While a truly green building also considers items such as material and water savings, the focus for this project was on achieving actual energy savings through strategic choices. All project paybacks were designed to be achieved in 10 years or under. In terms of direct economic benefits, the retrofits made to Nova Scotia Power will save an estimated $650,000 a year in electricity and water bills.
This strategy was successful as the project achieved all 10 LEED Optimized Energy Performance points, is designed to save 57 per cent energy compared with a conventional office, and achieved an Energy Star score of 89 (indicating Nova Scotia Power is more energy efficient than 89 per cent of buildings in North America).
Curtain Wall and Re-Skinning
One of the building’s main features is the new exterior skin, which consists of an improved thermal barrier by incorporating low-e films on the glazing. The frames of the curtain wall system have improved thermal break to reduce heat transfer. The new roofing system is a key item to the re-skinning as it adds additional insulation to the current structure and uses a high-albedo white roofing material to reduce heat gain.
Harbour Heat Pumps
The mechanical system draws heating/cooling from Halifax harbour. The system extracts sea water to run through the titanium heat exchanger to prevent corrosion while heat pumps transfer the needed cooling and heating from the circulation loop, sending it to the chilled beams and perimeter heating. The system has a by-pass for free cooling when the water temperature from the harbour is adequate. In addition, the building is able to move loads around during periods of simultaneous heating and cooling, and only needs to draw from the harbour to make up the short fall or reject excess load. This technology can be applied to buildings located near large bodies of water.
The building features chilled beams to decrease energy use and increase thermal comfort. A chilled beam is an induction unit mounted on the ceiling. An induction unit is a unit that delivers fresh air with the ability to add heating or cooling. The cooling unit’s airflow stays low until it is warmed by someone or something. This design maximizes the effectiveness of getting the fresh air to where it is needed, and removes stale air.
Lighting System and Natural Lighting
The new skin of the building incorporated more glazing to provide the occupants with access to views and daylight. Over 75 per cent of occupied spaces have access to daylight. Occupancy and daylight sensors are being used throughout the building to reduce or eliminate unnecessary lighting. As Nova Scotia Power is an electric utility, the project took a leadership role in eliminating lighting being on when there is available natural light to the space. When natural light is not adequate, the lighting system was design to use minimal energy by using highly efficient T5/T8 lighting fixtures.
A Community Landmark
The project is the starting point of Halifax’s boardwalk, providing not only the employees of Nova Scotia Power access to the harbour but also pedestrian access to the general public. The boardwalk enhancement includes a café with a patio and a large open green space consisting of native species plants. Locating the project in downtown Halifax instead of on the outskirt of the city supports urban development rather than sprawl. Additionally, Nova Scotia Power hosts an emission-free, all-electric vehicle onsite for employee. The company has also announced a partnership with Discovery Centre, a popular local science museum that will see the non-profit move into the remaining space in the building currently unused by Nova Scotia Power.