Overview
ISO 18292:2011 - "Energy performance of fenestration systems for residential buildings - Calculation procedure" defines a standardized method to calculate the energy contribution of windows, doors and skylights (fenestration systems) in residential buildings. The standard converts product thermal and optical properties into comparable energy performance indices for heating and cooling, using national or local climate data and reference building specifications. It is intended for manufacturers, regulators, energy assessors and designers who need transparent, reproducible window energy ratings.
Key topics and technical requirements
- Scope: Applies to complete fenestration systems (frame, sash, glazing and shading) in residential buildings and covers both heating and cooling seasons.
- Inputs required:
- Thermal transmittance (U-value) of the whole system.
- Total solar energy transmittance (g-value or SHGC) and solar-optical data.
- Air infiltration / permeability and ventilation characteristics.
- Relevant climatic data and reference building parameters.
- Calculation methods: Supports monthly, seasonal and hourly energy-balance procedures (per ISO 13790) so calculations can be adapted to accuracy needs and data availability.
- Outputs: Annual fenestration energy performance indices-separate values for heating (P_E,H,w) and cooling (P_E,C,w), expressed in kWh/m² per year (energy need contribution per unit area).
- Additional elements:
- Daylight potential is defined (DP) but not included in the energy performance value.
- Procedures account for all climatic conditions and installation details; regulatory authorities select applicable clauses, climatic data and reference buildings.
- Documentation: Standard specifies the assessment report content and references related test standards (thermal, solar, air permeability).
Applications and users
- Window, door and skylight manufacturers - to demonstrate product energy performance and compare designs.
- Energy assessors and certifiers - to derive product ratings for building energy labeling and compliance checks.
- Building designers and architects - to evaluate fenestration impact on heating/cooling loads and to optimize glazing and shading strategies.
- Regulators and standards bodies - to specify national rating rules, climate data and reference building types for market regulation.
- Test laboratories - to translate measured U-values, g-values and infiltration data into annual energy metrics.
Related standards
Relevant complementary documents (cited in ISO 18292) include:
- ISO 13790 (building energy calculation methods)
- ISO 10077-1/2, ISO 15099 (thermal performance of windows and frames)
- ISO 9050 / EN 410 (glazing solar and luminous properties)
- ISO 15927 series (climatic data)
- EN 13363 (solar protection devices)
ISO 18292:2011 is a practical, standardized bridge between component test data (U-value, g-value, air permeability) and meaningful fenestration energy performance metrics used for regulation, product rating and energy-conscious design.