China Resources Building

Built in 1983, China Resources Building (CRB) is going to upgrade itself so as to compete with other new buildings. Daniel Kwan, Deputy General Manager of China Resources Property Limited (CRPL) 2, stated the challenges ahead.
“Currently, the take-up rate of CRB is around 80%, 10% lower than the period before financial tsunami. Many of the tenants moved to districts of lower rent rate”, he said.
Winson Chow, Managing Director of CRPL, expressed his opinion on the building’s future, “Although the CRB is already 25-year old, CRPL does not want to demolish the building. Instead, a more environmental friendly way should be considered.” In order to bring the CRB into the 21st Century, Ronald Lu & Partners (Hong Kong) Limited was appointed as the Renovation Project Architect and Ove Arup & Partners Hong Kong Limited 3 as the LEED Consultant to provide green strategies for refurbishment.

Use the Rating Tools

To assess the environmental performance of building projects, sustainability rating tools can be used. Among various choices available in the market, Leadership in Energy and Environmental Design (LEED) rating system is selected
as the sustainability framework and benchmark for the CRB. Developed by U.S. Green Building Council (USGBC) 4, LEED is considered to be a well-recognized standard. As of April 2009, there are over 19,000 projects registered under LEED
systems around the world including Singapore, Thailand, India and China.

According to Raymond Yau, an Arup fellow and Director of Ove Arup & Partners Hong Kong Limited, “the existing structures will be reused so as to minimize the waste generated during the renovation process and extend the lifetime
of existing landfills”. The new CRB will be the first major renovation project in Hong Kong to receive a gold rating from the certification scheme.

Sustainable Features

Based on the LEED rating system, the building sustainability is assessed in five major aspects including Site, Water, Energy, Materials and Indoor Environment Quality.
Site: Although CRB is situated in the prime location in Wan Chai North Area offering great community connectivity and convenient public transportation, 57 bicycle storages and 27 shower facilities will be provided to the building
users so as to encourage “Green Travel”. In fact, the Planning Department will conduct a study exploring the feasibility of connecting the Island East and West along the promenade. Mr. Wang-tai Wong, Wan Chai District Council
Member, believed that the bicycle facilities will have a positive impact on promoting the cycle track in Hong Kong Island.

Water: In order to cut unnecessary water usage and waste in more efficient ways, the native or locally adapted plants will be chosen for landscape design and water-saving fixtures such as low-flow faucet with sensor control will
be used. Compared with the LEED Standard (Per US Energy Policy Act 92) 5,11,180m3 of water can be saved, which is equivalent to the water volume of 4.5 Olympic pools.
Energy: Both building owners and building occupants want to reduce the running costs of the building, especially on energy use. In the CRB, this aim will be achieved through facade modification and upgrade of E&M equipment.
Apart from the aesthetic consideration, the building facade is designed to ensure high performance through optimizing and balancing the energy and daylight. Glazing system which allows only 5% of solar energy transmitted
to the indoor is used. Moreover, high air-tightness of the facade is ensured to minimize AC cooling load due to infiltration to a minimum.

For the renovated spaces, high efficient and innovative lighting system such as daylight sensor and occupancy sensor are proposed. When the occupancy sensor finds that the space is unoccupied for a pre-set period of time, the
lighting system of the controlled zone will be automatically turned off.
For the HVAC system, the air handling unit (AHU) will be upgraded with the installation of CO2 demand control ventilation (DCV) system. In contrast to the traditional method ventilating a space at a fixed rate, DCV system adjusts the amount of outside air entering the indoor space based on the CO2 amount generated by building occupants. As a result, the DCV system can control the outside air flow rate based on the actual occupancy to save energy.

Compared with the LEED Standard (Per ASHRAE 90.1-2004 ) 6, an annual energy saving of 1.65GWh is predicted by computer simulation, It is equal to the annual energy consumption of 5,200 fluorescent tubes operating in
24-hour mode. Furthermore, 1,370 Tons (or 7.5%) of CO2 emission is reduced per year, which is equivalent to the annual CO2 absorption by 200,000 pine trees. A measurement and verification plan will be developed to evaluate
and optimize the energy system performance.

Materials: The existing structural frame will be remained and reused for the CRB project so as to minimize the construction waste generated and the resources demanded. 75% of waste (estimated to be 53 tons) produced during
construction will be diverted from disposal. Also, the LEED credits requiring building materials containing a minimum of 10% (based on total materials value) of recycled and regional contents (within 800km of the project site)
are targeted. By using regionally manufactured building materials, carbon footprint due to the transportation activities by trucks, trains, ships and other vehicles can be reduced.

Indoor Environment Quality (IEQ): More than 70% of our time is spent in the indoor environment. Therefore, IEQ is important to the building users’ health, comfort and well-being. To prevent IEQ problems from arising, one of
the practical ways is to specify materials that release fewer and less harmful chemical compounds. In the areas to be renovated of CRB, adhesives, sealants, paints, coatings and carpet system with low volatile organic compounds (VOC)
contents will be used. Hence, the potential of causing sick building syndrome (such as headache, itchy eyes, respiratory difficulties, skin irritation, etc.) due to exposures to irritating and harmful contaminants can be greatly reduced.

For providing building occupants with optimal air quality, the outdoor air ventilation rates are increased by 30% above the minimum rates required by ASHRAE Standard 62.1-2004 7. DCV system is used to control the outdoor air
flow rate at an optimum level such that the balance between the IEQ and energy can be achieved.

Conclusion

As the role model of existing buildings transforming to GREEN, the CRB adopted the LEED framework for renovation in order to improve its sustainability on different aspects. It is expected that the CRB will be the first renovation project to achieve LEED-CS Gold Rating in Hong Kong. Retaining and reusing the existing building structure, construction waste generated during the renovation process is minimized, in addition, the building life cycle extended and the property asset value increased. It is hoped that the CRB experience can provide building owners with choices to rejuvenate their buildings other than demolition.

1 Hong Kong Property Review 2009 is published by the Rating and Valuation Department, the Government of Hong Kong Special Administrative Region.
2 China Resources Property Limited is one of Hong Kong’s bestknown property companies, with extensive experiences in development and management of commercial and residential properties. It administers in Hong Kong a portfolio of Class-A offices, high-class residential apartments, luxurious houses and large scale retail premises, with a total area of over 2 million ft2.
3 Arup is a global firm of designers, engineers, planners and business consultants providing a diverse range of professional services to clients around the world. Their innovative and fullyintegrated approach brings full complement of skills and knowledge to bear on any given design problem. They are the creative force behind many of the world’s most innovative and sustainable designs. Arup has over 10 000 staff working in more than 90 offices in 37 countries.
4 The U.S. Green Building Council (USGBC) is a 501(c)(3) non-profit organization that certifies sustainable businesses,
homes, hospitals, schools, and neighborhoods. USGBC is dedicated to expanding green building practices and
education, and its LEEDR (Leadership in Energy and Environmental Design) Green Building Rating System^TM.
5 The Energy Policy Act (EPAct) of 1992 was promulgated by the U.S. government and addresses energy and water use in commercial, institutional and residential facilities.
6 The American Society of Heating, Refrigerating and Air-Conditioning Engineers Inc. (ASHRAE) is an international technical society for all individuals and organizations interested in heating, ventilation, air-conditioning and refrigeration. It formulated the Standard 90.1-2004 which establishes minimum requirements for the energy-efficient design of buildings, except low-rise residential buildings.
7 The ASHRAE Standard 62.1-2004 specifies the minimum ventilation rate and indoor air quality that will be acceptable to human occupants and are intended to minimize the potential for adverse health effects.