Passive Building Design

Passive Building Design is a design technique to achieve very low energy demand for space heating and cooling. The buildings walls, windows and floors can be designed to collect, store, and distribute heat and solar energy. It maximizes the use of natural elements to aid or replace fossil fuel energy sources that traditionally have heated and cooled our buildings. 

Passive Energy Techniques 

Daylighting, natural ventilation, and solar energy are the most common techniques to achieving passive design, which takes advantage of the site location, climate, and materials to minimize its energy use. This uses the natural rotation of the sun and carefully considered design aspects to the building to harness the light and heat to control comfortable climate. 

5 Passive Design Strategies 

1. Super insulated envelopes – In cold climates like Canada where the inside air is heated for comfort, some of that air will be lost as it moves through the insulation envelope. To prevent this insulation made of low-conductivity materials is installed within the walls and roof assemblies. To super-insulate the building double or triple the insulation is used. 

1. Airtight Construction – Heat can be lost through the envelope seal during construction. To prevent this a suitable ventilation strategy is used to deal with excess humidity in the building, such as the effective use of air barriers during planning and construction. 

1. High-performance glazing – Windows and doors play a huge role when it comes to contributing to space heating. Often the windows and doors are the weakest point in the envelope. To avoid this, include nonconductive framing or large thermal breaks, insulated framing, double or triple glazed units, warm edge, or nonconductive spacers. This will seal the framing to make them airtight leaving no gaps for any additional leakage. 

1. Thermal-bridge-free detailing – The easiest way to avoid thermal bridging is by making architectural design changes, such as articulating architecture on large buildings. Reducing direct conductive connection between the interior and exterior is important.  

1. Heat recovery ventilation – A passive building will be air-tight, a ventilation system is needed to bring fresh air and exhaust out pollutants, odors, CO2, and moisture. A passive house ventilation system uses a heat recovery ventilator to continuously remove stale or moist air and replace it with fresh air. 

Is Passive design Sustainable?  

Sustainable design principals aim to optimize site potential, making passive design one of the foundations of sustainable architecture. The passive design principles use the different elements of passive design to work together providing thermal comfort and achieving optimal energy efficiency.