Introduction
Buildings in Hong Kong consume about 90% of the electricity and contribute around 60% of the carbon emissions. Most of the carbon emissions come from the electricity consumption within buildings. Electricity is the major form of energy supply for the majority of the buildings in Hong Kong.
Hong Kong’s Climate Action Plan 2050 has set a pathway for decarbonising the electricity supply before 2050. The building sector should be playing a prominent role in decarbonising the demand side which is to reduce the energy consumption within buildings.
Building owners have been reducing their energy demand, in particular, electricity consumption, reporting their performance and applying for green finance for their improvement projects. However, the industry lacks clear definitions and benchmarking scheme to gauge energy performance of buildings. They are puzzled with what targets they need to set for their buildings in order to align with the Paris agreement.
The industry is in need of a benchmarking scheme to gauge the energy performance of their buildings together with a target setting tool that can facilitate them to set their targets to align with international carbon neutrality targets.
To address this, the Hong Kong Green Building Council (HKGBC) has established a Zero-Carbon-Ready Building Certification and a Net Zero Energy Building Certification, launched in September 2023 and March 2024 respectively. The certifications form part of the HKGBC Climate Change Framework for Built Environment, launched in June 2023.
Purpose and objectives
The purpose of the certifications is to provide aligned definitions, calculation methodologies and targets among industry stakeholders.
By adopting the certifications, building owners can:
- benchmark and report the energy performance of their buildings
- set their targets for carbon neutrality and tracking their progress
- justify their improvement projects for green financing
- definite their buildings as net zero energy consumption
Target
The International Energy Agency (IEA) defines zero-carbon-ready buildings as highly energy efficient and resilient buildings that either use renewable energy directly, or rely on a source of energy supply that can be fully decarbonised, such as electricity or district energy.
This definition and criteria are adopted due to the fact that the concept of “Zero-Carbon-Ready Building” is well accepted internationally and Hong Kong has already committed to fully decarbonised their electricity supply.
The criteria of ‘highly energy efficient” is established with the energy database as described below or achieving a significant reduction of energy demand making reference to international practice which is about 65% reduction from the baseline.
Database and baseline
Under the Zero-Carbon-Ready Certification, the HKGBC has established a database and set the baseline for energy utilisation index (EUI) for commercial buildings. The database is established from the relevant data collected in the last mandatory energy audit prescribed by the EMSD in 2012-2015, surveys of office premises and BEAM Plus submissions to ensure the robustness of the tool. The baseline is set as the 50th percentile of the database for the energy performance calculator and the certification.
Development of the tool also made reference to the Science Based Targets initiative (SBTi) for determining the percentage reduction for target setting that can link with the carbon budget defined by Intergovernmental Panel on Climate Change (IPCC) for below 2°C.
Only the electricity consumption within Scope 2 defined by the Greenhouse Gas Protocol is included in the certification. Other energy consumptions may be taken into account at a later stage when proved to be necessary.
According to the Hong Kong’s Climate Action Plan 2050, the Government has set energy reduction targets and decarbonisation strategies for buildings, using the operational conditions of 2015 as the comparison basis. Therefore, the the baseline year, 2015 set in this Framework is in line with the baseline year set in the Hong Kong’s Climate Action Plan 2050 for determining the percentage reduction of building’s energy consumption.
It will not be practical to go for accuracy as each building is designed and operating differently. The emphasis is more on consistency. The calculator has provided the normalisation method and default values for some unusual situations that have a significant impact on the outcomes.