A Smart Approach to Low Energy


When most people hear of energy-efficient building techniques or high-performance buildings, they assume that there must be a cost premium associated with the increased efficiency. However, this is not always the case. Some of the premiums typically associated with energy efficiency can be reduced if planned for with a strategic method. When designing a building, or renovating a building, with energy-efficiency in mind, it is important to consider passive measures as a first priority, followed by active measures, and then last consider renewable options. What do these terms mean, and why this specific order?

Passive measures include things like building orientation and massing, which would optimize the building for daylighting, shading, and natural ventilation. Properly orienting and massing a building is a highly effective way to lower energy use, and may be very simple and inexpensive to accomplish when taken into account in the early phases of design. Other passive measures include insulation, air-tightness, and high-performance windows and doors. If your building has ideal natural light coming through the windows, your need for electrical lighting could be significantly reduced. If your building is well-insulated and airtight, the cooling and heating loads would be significantly reduced. These reductions then impact the size and cost of the "active" electrical and mechanical systems that are required in the building. 

After the passive measures have been implemented, the second priority should be to maximize efficiency of the building's active systems: electrical, mechanical and plumbing systems. These could include many options such as LED lighting, Energy Star equipment, low-consumption plumbing fixtures and energy recovery ventialtion systems. 

And finally, after the passive and active measures have been considered, renewable energy systems may be implemented. Examples of renewable systems include photovoltaic panels, solar thermal collectors, geothermal heat pumps, wind turbines and hydroelectric turbines. In some instances, combining passive and active measures may impact energy consumption enough that renewable measures are not required, or would be considerably reduced. Therefore by first implementing passive and active systems, the investment required to implement a renewable energy system could be eliminated or decreased.