What is Passive House: A voluntary standard for energy efficiency in a building, which reduces the building’s ecological footprint. It results in ultra low energy buildings that require little energy for space heating or cooling.
Passive House is a standard that opens up completely new perspectives for architects and engineers. Industry is responding positively to Passive House driven market needs by developing highly efficient, pioneering products and making them available on the market. Passive House, as such, drives economies and innovation. An investment in comfort and efficiency thus adds value throughout the supply chain.
How did it start: Much of the early ‘Passive Houses’ were based on research and the experience of North American builders during the 1970s, who in response to the oil embargo sought to build homes that used very little or no energy.
How did the Passive House Standard form? The Standard originates from a conversation in May 1988 between Bo Adamson of Lund University Sweden and Wolfgang Feist of the Institute for Housing and the Environment, Darmstadt Germany. Later, their concept was further developed through many research projects aided by financial assistance from the German state of Hessen.
Where does Passive House standard apply: The standard is not confined to residential properties; several office buildings, schools and supermarkets have also been constructed to the standard. Passive design is not an attachment or supplement to architectural design, but a design process that integrates with architectural design.
Which are the main Passive House features?
- Space Heating Demand should not exceed 15kWh annually or 10W (peak demand) per square meter of usable living space. This is the equivalent of 1.5m3 of natural gas per square meter of living space.
- Space Cooling Demand should roughly match the heat demand with an additional, climate-dependent allowance for dehumidification.
- Primary Energy Demand should not exceed 60kWh annually for all domestic applications (heating, cooling, ventilation, hot water and electricity) per square meter of usable living space, being produced by renewable energy resources.
- Airtightness with a maximum of 0.6 air changes per hour at 50 Pascals pressure.
- Thermal Comfort must be met for all living areas year-round with not more than 10% of the hours over 25°C without the use of active cooling.
How does Passive House achieve this performance?
- Correct orientation of the building, with shading elements above windows to the North and minimal openings to the South
- Building envelope enclosed by insulation without interruption
- Thermal break windows with double or triple glazing
- Glazing allowing the exploitation of solar energy
- Thermal bridge-free design
- Mechanical ventilation with heat recovery
- Filtered circulating air
Passive House offers a realistic, cost effective solution for an economical building that provides a high level of living comfort while using very little energy for heating and cooling. In times of rapidly increasing energy prices and global warming, it is the Nearly Zero Energy Building (NZEB), low carbon, Net Zero Energy Building standard with decades of science backed evidence and satisfied residents.
Buildings that meet the Passive House standard use approximately 80% less energy than equivalent conventional buildings and provide superior air quality and comfort. The ventilation system recovers residual energy from indoor air before pushing that out and uses it to condition the incoming air. Thanks to the quality insulation and efficient ventilation system, Passive House remains warm on cold days and comfortable and cool on warmer days.
The use of Passive House planning methodology in the renovation of existing buildings begins by replacing the building components that are most in need of replacement. After an initial assessment, our practice conducts an individualised plan that ensures the new measures fit together and the result is a comfortable internal environment with significantly reduced heating and cooling costs.
As the additional capital expense will take some years to depreciate through reduced operational cost, if your target is a short term investment, this path might not be the right choice for you.