JASE-W (Chairman: Masakazu Tokura, Chairman of the Japan Business Federation (Keidanren)) aims to contribute to the reduction of GHG emissions through the excellent energy-saving technologies and products of its member companies. In this way, the public and private sectors are aligned in the promotion of energy-saving and renewable energy technologies in countries around the world, particularly in fast-growing regions.
With the support of METI, the working group discussed repeatedly and proposed the Technical Specification TS23764 to ISO in May 2020. The specification approved and issued this time outlines the basic items to be considered in the entire process of ZEB realization, from the design to the operation and maintenance stages. In formulating the specification, the working group referenced the "Step-by-step Approach to Achieving ZEB" of the ZEB Roadmap Examination Committee, which was established under the direction of METI's Agency for Natural Resources and Energy.
*1 ISO International Organization for Standardization
*2 ZEB Zero Energy Buildings
Buildings that aim to reduce the balance of primary energy consumption to zero.
Background and purpose of the publication
The building sector accounts for 30% of the world's energy consumption, and expectations for its reduction seems to be increasing [source: IEA World Energy Outlook 2020]. Therefore, reducing GHG emissions from this sector is an important global challenge, which ultimately requires reducing the energy consumption of buildings and balancing it with renewable energy to achieve (net) ZEB.
While the ultimate goal of achieving ZEB is clearly understood, its achievement has been constrained by practical barriers such as high upfront investment. However, due to the long life cycle of buildings, designing and constructing more energy-efficient buildings is not considered a future attempt to reduce GHG emissions, but a present attempt. Therefore, we are facing a challenge to accelerate the movement toward ZEBs.
In this context, TS23764 advocates a step-by-step approach to the realization of (net) ZEB. Its purpose is to embody practical ways to realize ZEBs in order to accelerate the movement toward ZEBs. In other words, this specification proposes a practical ZEB approach and outlines the basic considerations that should be taken into account in the entire process of ZEB realization, from the design to the operation and maintenance stages.
1. At planning stage, to have clear policy to achieve ZEB by the three steps, ZEB Ready → Nearly ZEB → (net) ZEB, but not to achieve it by only one step to (Net) Zero Energy Building.
Source: ISO TS23764 4.4.4 Figure 3
3. During construction, to install the selected materials and equipment correctly according to the drawings and specifications.
4. After completion of building, to realize the energy consumption targeted at the design stage.
5. After operation start, to inspect actual energy consumption continuously (suitable times per year) whether there is any difference of energy consumption between the targeted at design stage and the measured at actual operation.
6. After the start-up of the operation, to calculate the primary energy consumption periodically by using simulation software, if possible.