Passive House (Passivhaus) is a performance-based building standard developed to minimize space heating energy demand through highly efficient building envelope design and controlled ventilation. The defining criterion is a heating energy demand below 15 kWh/m²a, achieved primarily through passive measures rather than active heating systems. The standard applies to residential and non-residential buildings and is climate-adaptable, with design parameters adjusted according to regional conditions.
Core Design Principles
The Passive House concept relies on five interconnected principles: continuous thermal insulation without gaps, airtight building envelope construction, elimination of thermal bridges at junctions and penetrations, high-performance glazing and frame systems, and mechanical ventilation with heat recovery. These elements work together to reduce heat losses to the point where minimal supplementary heating is required, even in cold climates.
Mechanical Ventilation with Heat Recovery
Because airtight envelopes prevent uncontrolled air exchange, mechanical ventilation systems are mandatory in Passive House buildings. Heat recovery ventilation units extract heat from exhaust air and transfer it to incoming fresh air, maintaining indoor air quality without significant energy loss. System sizing and duct layout must be planned early in the design process, as retrofitting ventilation infrastructure into a completed structure is difficult and costly.
Thermal Bridge-Free Design
Thermal bridges—localized areas of increased heat flow through the envelope—are systematically avoided in Passive House design. This requires careful detailing at balconies, foundations, window reveals, and roof-wall junctions. Thermal bridge-free construction is verified through detailed junction calculations during the planning phase, not merely through material selection.
Certification and Verification Tools
Compliance is typically verified using the Passive House Planning Package (PHPP), a specialized calculation tool that models the building's energy balance based on geometry, orientation, envelope assembly, and climate data. Certification is issued by accredited Passive House certifiers following plan review and, in many cases, on-site airtightness testing. Certification is voluntary and distinct from national energy performance regulations, though it can be used to demonstrate compliance with regulatory requirements in some jurisdictions.
Distinction from Related Terms
Passive House differs from the broader category of low-energy or energy-efficient buildings, which may achieve reduced consumption without meeting the specific heating demand threshold or airtightness requirements of the Passive House standard. It also differs from nearly zero-energy building concepts, which typically include on-site renewable energy generation as part of the compliance pathway; Passive House focuses primarily on demand reduction rather than energy supply. For retrofit projects, a separate standard—EnerPHit—applies, recognizing that existing building constraints often make full Passive House performance levels technically or economically unfeasible.
Application Limits
Passive House performance depends strongly on climate, orientation, and building form factor (the ratio of envelope surface area to enclosed volume). Compact building geometries are inherently easier to bring to standard than buildings with complex massing or large glazed facades. In retrofit contexts, existing structural conditions, heritage constraints, or adjoining buildings can limit the extent of envelope upgrades achievable, which is why retrofit-specific criteria exist separately from new-build certification requirements.