ISO 10077-2-2017 PDF

Full title and description

ISO 10077-2:2017 — Thermal performance of windows, doors and shutters — Calculation of thermal transmittance — Part 2: Numerical method for frames. This part specifies a numerical method and reference input data for calculating the thermal transmittance of frame profiles and the linear thermal transmittance at their junctions with glazing or opaque panels; it also gives criteria for validation of numerical calculation methods.

Abstract

Specifies a finite‑element (numerical) procedure and reference input data to determine the thermal transmittance (heat transfer) of window/door frame profiles and the linear thermal transmittance of frame–glazing or frame–panel junctions. The document may also be used for shutter profiles and roller‑shutter boxes; it excludes effects from solar radiation, air leakage, three‑dimensional pinpoint metallic connections and thermal bridges between frame and building structure.

General information

• Status: Published (International Standard).
• Publication date: June 2017 (Edition 3, 2017‑06).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 91.060.50 (Doors and windows); 91.120.10 (Thermal insulation of buildings).
• Edition / version: Edition 3 (2017). Amendment 1 published 2024 (ISO 10077-2:2017/Amd 1:2024).
• Number of pages: 70 (main publication); Amendment 1 adds 17 pages.

(General information based on the ISO bibliographic record and published amendment.)

Scope

Provides a validated numerical method and reference input data for calculation of thermal transmittance of frame profiles and linear thermal transmittance of their junctions with glazing or opaque panels. Applicable to frame materials (wood, plastics, metal with/without thermal breaks) and to components such as shutters and roller‑shutter boxes. The standard explicitly does not account for solar gains, heat transfer due to air leakage, detailed three‑dimensional point metallic connections or thermal bridge effects between the frame and the building structure.

Key topics and requirements

• Numerical calculation method for frame thermal transmittance (finite‑element / numerical approach).
• Reference input data for material thermal conductivities and boundary conditions.
• Criteria and procedures for validation of numerical methods and software.
• Calculation of linear thermal transmittance at frame‑to‑glazing or frame‑to‑panel junctions (psi values).
• Reporting requirements and templates (input/method selection data sheets and default choices in annexes).

Annexes include normative and informative input/data sheets and regional references and lists of material properties to support consistent calculations.

Typical use and users

Used by window/door/frame product manufacturers for product development and performance declarations; testing and certification laboratories for method validation; independent thermal consultants and energy modelers preparing U‑factor and linear thermal transmittance (psi) inputs for building energy calculations; standards committees and regulatory bodies adopting or referencing harmonized calculation methods. Typical outputs support product datasheets, compliance documentation and energy‑performance assessments.

Related standards

ISO 10077-1:2017 (Part 1 — General: methods for calculating whole‑window/door thermal transmittance) is the companion document that describes general calculation rules and how Part 2 integrates for frame calculations. National and regional adoptions exist (for example EN/BS/NEN national implementations of EN ISO 10077‑2:2017).

Keywords

thermal transmittance, U‑value, linear thermal transmittance, psi value, frames, window frames, doors, shutters, numerical method, finite‑element, validation, ISO 10077

FAQ

Q: What is this standard?

A: ISO 10077‑2:2017 is the part of the ISO 10077 series that specifies a numerical method and reference input data to calculate the thermal transmittance of frame profiles and the linear thermal transmittance of their junctions with glazing or panels.

Q: What does it cover?

A: It covers the numerical calculation method, reference material data, validation criteria for calculation methods/software, and reporting templates; it does not cover solar radiation effects, air‑leakage heat transfer, certain 3‑D metallic connections or thermal bridges to the building structure.

Q: Who typically uses it?

A: Frame and window manufacturers, independent test and certification labs, thermal consultants and energy modelers, and regulatory/standards organisations that need consistent, validated frame U‑value and linear transmittance inputs for energy performance assessments.

Q: Is it current or superseded?

A: The edition in force was published in June 2017 (Edition 3). An Amendment 1 to ISO 10077‑2:2017 was published in December 2024; users should apply the base standard together with the published amendment where required.

Q: Is it part of a series?

A: Yes — ISO 10077 is a multi‑part series. Part 1 (ISO 10077‑1:2017) contains general calculation rules for whole windows/doors; Part 2 (this document) provides the frame numerical method. Other related standards and national/regional adoptions implement the series for regulatory and product assessment use.

Q: What are the key keywords?

A: thermal transmittance, frame U‑value, linear thermal transmittance, psi, numerical method, validation, window frames, doors, roller‑shutter boxes.