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  5. New Energy Efficiency Standards for Sashes and Insulated Glass Compiled

New Energy Efficiency Standards for Sashes and Insulated Glass Compiled

March 10, 2022

A working group established under the Agency for Natural Resources and Energy (ANRE) compiled new target standard values for sashes and insulated glass as building materials under the Top Runner Program.

Today, a working group on the Top Runner Program1 established under the Agency for Natural Resources and Energy (ANRE) compiled new target standard values for sashes and insulated glass as building materials under the Top Runner Program based on the Act on the Rational Use of Energy (Act No. 49 of 1979), which they began discussing in June 2021.
The new target standard values for windows that combine sashes and insulated glass have been increased by about 40%. The heat insulating efficiency required for windows is calculated from the required energy efficiency performance for new houses built from 2030 onward.2

Outline of the new target standard values for sashes and insulated glass under the Top Runner Program

Target equipment:

Sashes and insulated glass used mainly in houses and low-rise shared residential buildings

Target fiscal year:

FY2030

Category:

  1. Sashes: 5 categories by opening and closing method (sliding, vertical casement, horizontal casement, fixed, and double-hung)
  2. Insulated glass: 1 category

Target standard value:

Next target reference value for sashes and insulated glass, and the improvement rate3 from the current target reference values are as follows4.

Notes:

  1. Working Group on Classification Standards for Building Materials, etc. of the Energy Efficiency and Conservation Subcommittee of the Committee on Energy Efficiency and Renewable Energy under the Advisory Committee for Natural Resources and Energy

  2. The heat insulation performance required for windows in 2030 will be 2.08 [W/(m2・K)].

  3. Because the expected performance values for standard glass differ between the current and next target standard values for sashes, the performance improvement rates are not solely based on sashes. Furthermore, the new values are calculated based on representative sizes.

  4. The next target values for sashes and insulated glass will be calculated based on the insulation performance required for windows in 2030.

Relevant materials

Report compiled by the Working Group on Classification Standards for Building Materials, etc. (Outline) (March 2022) (in Japanese)

Division in Charge

Energy Efficiency Division, Energy Efficiency and Renewable Energy Department, Agency for Natural Resources and Energy