Very low energy buildings
Very low energy buildings can be defined as buildings that are designed to provide even higher standards of energy efficiency and low environmental impact.
Very low energy houses are commonly designed without traditional heating systems and without active cooling, resulting in energy savings of 70 to 90 % compared to the existing building stock. Main elements to contribute to this low energy performance, taking into account high level of requirements for health, comfort and cost-efficiency, are:
- Very high level of energy performance of the building envelope
- High thermal resistance
- Avoidance of thermal bridges
- Excellent air sealing
- Controlled and energy efficient ventilation
The Passive House is generally the most well-known type of very low energy since it is the oldest concept being devised in Germany in the 1990ies. It is generally recognised that the requirement for calling a building passive is that it lives up to the standards developed by the German Passive House Institute. Thus, most passive houses are found in Germany, Switzerland and Austria.
A Passive House is a well-insulated building which maintains a comfortable interior climate, utilising the free “passive” energy from body heat, solar gains and appliances as the key energy providers for heating.
How to build a Passive House:
- Proper insulation (300-500 mm Rockwool material)
- Low-energy, tripled-glazed windows
- No thermal bridges
- Controlled ventilation with efficient heat recovery
- Air-tight with all gaps sealed
- Optimal building orientation for solar gain or protection
- Low-energy appliances
- The annual heating demand may not exceed 15 kWh per square meter. The total primary energy consumption is limited to 120 kWh/m2
per year
Work is in progress to further develop the passive house concept since it is currently tailored to Central European building traditions and climate conditions.
A passive house is a well-insulated building which maintains a comfortable interior climate with a minimum energy demand.
