PROMOTING ENERGY EFFICIENCY BUILDINGS
Commercial buildings are the primary energy consumer in the commercial sector, accounting for 34 per cent of total energy end-use. It was in this context that the Energy Efficiency Registration Scheme for Buildings was launched in 1998 to encourage developers and architects to adopt energy efficient building designs. The scheme provides a voluntary framework for implementing the Building Energy Codes, which set out the minimum energy efficiency requirements for buildings in terms of power consumption, system design, and monitoring provisions for these installations.

The current set of four Building Energy Codes, all developed by EMSD, covers air-conditioning, lighting, electrical, and lift and escalator systems. The codes for electrical installations and lift and escalator installations are the first of their kind, and have drawn widespread interest from the industry - both locally and in the United States, where the Institute of Electrical and Electronics Engineers is considering including them in their standards.

Compliance with the codes ensures that the installations achieve a minimum level of energy efficiency, reduce power consumption and are conducive to environmental protection. In turn, this translates into savings in money for landlords and tenants. Those meeting the code standards will be issued a registration certificate and allowed to use the Energy Efficiency Building logo for publicity purposes. Recent reviews show that the scheme and the codes are well received by developers, property owners, architects and engineers. More than 100 certificates have been awarded so far.

Following up on the promotion of energy efficient buildings, a consultancy study will be commissioned to develop a performance-based code of practice for buildings taking a total-energy-budget approach. The code will cover energy efficient features currently not included in the existing codes, such as the use of natural light in building design and the recycling of waste heat. The new code aims to advocate a higher level of innovative building design.

WATER-COOLED AIR CONDITIONING SYSTEMS
With air-conditioning accounting for a significant share of electricity end-use in Hong Kong, the government embarked some time ago on a study of the viability and overall economic and environmental benefits of using Water-cooled Air Conditioning Systems (WACS) in the territory. Territory-wide conversion of air-cooled air-conditioning systems to the more energy-efficient WACS has a potential to reduce greenhouse gas emissions by 600,000 tonnes a year, and save 7 to 10 per cent of energy used for air conditioning in non-domestic buildings. This translates into between $977 million and $1,500 million in energy savings a year, at current electricity costs.

District Cooling System
District Cooling System (DCS) has been identified as a type of WACS that can bring tangible benefits to developers, landlords and tenants as well as society as a whole. EMSD was tasked with conducting two implementation studies: one in South East Kowloon Development (SEKD), and one in an existing district, Wanchai and Causeway Bay (WCCB).

The SEKD study, which is in progress, is to identify the technical, environmental, and institutional requirements of DCS implementation, including legislative, regulatory, financial, economic and land use issues. Potential customers may include commercial buildings and shopping malls, government and community buildings, and underground railway stations.

The WCCB study commenced in December 2001 for completion in 2003. As the district has a balanced mix of offices, commercial developments, hotels and government offices, it is expected to have good potential for the development of WACS.

We are now formulating plans and strategies for the phased implementation of WACS in the two districts, taking into account the complex issues of future district development, traffic arrangements, land uses, financing, infrastructural constraints, regulatory and institutional framework, WACS technology development and environmental impact, and with a view to minimising the disruption to business and the local community.