ISO 10077-1-2017 (2020) PDF

Full title and description

Thermal performance of windows, doors and shutters — Calculation of thermal transmittance — Part 1: General (ISO 10077-1:2017). This International Standard specifies the calculation procedures and conventions used to determine the overall thermal transmittance (U-value) of windows and pedestrian doors made of glazed and/or opaque panels fitted in a frame, including options for shutters and national/adopted corrigenda (corrected reprint 2020).

Abstract

ISO 10077-1:2017 defines methods for calculating the thermal transmittance (U-value) of windows and pedestrian doors consisting of glazed and/or opaque panels in a frame, with and without shutters. It provides calculation conventions, recommended boundary conditions and default data in annexes; thermal bridge effects at the frame-to-building interface are excluded from the basic calculation and handled by separate methods.

General information

• Status: Published (confirmed edition).
• Publication date: June 2017 (ISO edition 3); corrected reprint (English/French) February 2020.
• 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); corrected version / reprint 2020-02.
• Number of pages: 40 (ISO official edition page count; national adoptions may have additional national forewords and different page totals).

Scope

Specifies calculation methods for the thermal transmittance of windows and pedestrian doors (glazed and/or opaque panels in frames), allowing for different glazing types, opaque panels, a wide variety of frame materials (timber, plastics, metal with/without thermal breaks) and the additional thermal resistance of closed shutters or external blinds where appropriate. The standard excludes thermal bridge effects at the rebate/joint between frame and building envelope (these are treated separately) and allows roof and projecting windows to be calculated provided appropriate input data for frame sections are available.

Key topics and requirements

• Calculation rules and conventions for overall window/door U-value (steady-state methods, presentation of results to two significant figures).
• Treatment of glazing U-values (reference to glazing calculation methods such as EN/ISO glazing standards for centre-of-glass values).
• Determination of frame U-values by measurement or numerical calculation (frame sections often calculated with glazing replaced by an insulating equivalent).
• Provision of default values and annex data for common materials and boundary conditions (surface resistances, emissivities).
• Notes on when numerical methods (ISO 10077-2) or thermal bridge standards (ISO 10211) are required (e.g., large conductivity contrasts, complex 2D/3D effects).

Typical use and users

Used by window, door and shutter manufacturers, façade and building-envelope engineers, energy assessors, testing laboratories, regulators and standards bodies for product performance calculation, product comparison, compliance with energy regulations and design optimization of frames and glazing systems.

Related standards

Key related documents include ISO 10077-2 (Numerical method for frames — calculation of frame U-values and linear thermal transmittance), EN/ISO glazing calculation standards (EN/ISO standards such as EN/ISO 673 for centre-of-glass U-values), ISO 10211 (thermal bridges — detailed calculations), and other building thermal standards such as ISO 6946 and ISO 13789 that reference ISO 10077 series for fenestration input. Guidance and technical reports (for example ISO/TR/EN guidance documents) explain correct application of the series.

Keywords

U-value; thermal transmittance; windows; doors; shutters; glazing; frame profiles; linear thermal transmittance; thermal bridges; ISO 10077; fenestration thermal calculation; numerical method.

FAQ

Q: What is this standard?

A: ISO 10077-1:2017 is the Part 1 (General) international standard that sets out the calculation conventions and methods used to determine the steady‑state thermal transmittance (U-value) of windows and pedestrian doors. It was published by ISO in June 2017 with a corrected reprint issued in February 2020.

Q: What does it cover?

A: It covers procedures to calculate the overall U-value for window and door assemblies (glazed and/or opaque panels in frames), recommended boundary conditions, default input data in annexes, and how to treat shutters and certain projecting windows; it excludes frame-to-building thermal bridge effects (those are addressed by separate standards).

Q: Who typically uses it?

A: Window and door manufacturers, façade and building-envelope designers, energy assessors, test laboratories, certification bodies and code/standards developers use ISO 10077-1 for product U-value calculation, product comparison and regulatory compliance.

Q: Is it current or superseded?

A: The 2017 edition (Edition 3) is the current ISO edition; ISO records show a corrected reprint in February 2020 and the edition was reviewed/confirmed in ISO review cycles (status shown as published/confirmed). Users should check national adoptions or later amendments for regional updates (some national adoptions were published in 2020 and Part 2 has received amendments more recently).

Q: Is it part of a series?

A: Yes — ISO 10077 is a multi‑part series. Part 1 is the general calculation rules; Part 2 (ISO 10077-2:2017) provides the numerical method for frame cross-section calculations and reference input data. Additional technical reports and related ISO standards (e.g., ISO 10211 on thermal bridges) are commonly used together with the 10077 series.

Q: What are the key keywords?

A: Thermal transmittance, U-value, windows, doors, shutters, glazing, frames, linear thermal transmittance, thermal bridge, numerical calculation, ISO 10077.