Zero Carbon Building | Ronald Lu & Partners

ZCB Zero Carbon Building (ZCB), the first zero carbon building designed to be energy-positive from a life-cycle perspective in the tropics, is a milestone for Hong Kong, in terms of its visions, design innovations, execution and implementation from the integrated process to the continual optimisation of the building performances in the operational phase since its opening in 2012. Besides serving as the test bed for state-of-the-art zero carbon design and technologies to the building industry, it is aspired to regenerate the ecological values of the site, liveable green infrastructures for the neighbourhood, and a place to drive paradigm shift towards sustainable living in the city through integrated design process in less than 15 months, Ronald Lu & Partners placed its first priority on energy conservation by passive design and the use of highly energy-efficient active systems. Passive design: - Building orientation to capture summer prevailing wind - Tapered and linear built form to enhance air flow as well as daylight, and reduce solar heat gain - Substantial non-air-conditioned transitional space with high building permeability - Cross-ventilated layout to enhance effective natural ventilation and reduce the demand of air-conditioning - High-performance envelope designed for hybrid ventilation: highly permeable and operable for cross ventilation for mild season and air-tight with high solar shading at an ultra-low Overall Thermal Transfer Value (OTTV) of 11 W/m2 (over 80 percent lower than maximum value required under current statutory control) for hot season - Earth cooling tube and chamber for pre-cooling (up to a 4 degree Celsius reduction) of hot summer air. Highly energy-efficient active systems: - High-Volume-Low-Speed (HVLS) ceiling fans to enhance air movement and reduce the demand of air-conditioning - Desiccant dehumidification to avoid overcooling of air for humidity control - Under-floor displacement cooling to effectively cool the inhabitant’s zone at a higher supply air temperature (5 degree Celsius higher than conventional A/C systems) - Radiant cooling by chilled beam to cool the inhabitants Renewable energy with High Fuel Energy Utilisation: - Bio-diesel Tri-generation - Photovoltaic (PV) panels (three different types: poly-crystalline, Building-Integrated thin-film and cylindrical CIGS) output energy 87MWh per year; the main building roof is inclined to maximise solar irradiance on PV panels - Solar thermal to generate hot water for eco-café area Regenerative Design To minimise the carbon footprint from construction, the site was transformed based on balanced cut and fill, to create higher planting zones along its perimeters. Acted as a buffering effect, the public plaza is well sheltered from air and noise pollution generated by busy road traffic surrounding the site. A vast open landscape area surrounding the building incorporates Hong Kong's first urban native woodland, achieving a high greenery coverage of over 50 percent. Approximately 370 trees are planted and each has the capacity to absorb 23 kg of carbon dioxide (CO2) a year. It successfully helps lower the local air temperature by up to 1 degree Celsius. The created ecosystem encompasses a diversity of species. Not only does this contribute to improving the microclimate of a dense urban area but also mitigating the urban heat island effect. Post-Occupancy Considerations To facilitate a continuous improvement, surveys are regularly conducted to seek customer/visitor feedbacks. Also, ZCB serves as a learning tool to inspire behavioural change. A Post Occupancy Evaluation is adopted to elicit the construction cost, operational cost, energy saving and carbon reduction. Overall Excellence and Positive Impacts ZCB fosters social and cultural harmony with the community. It operates daily guided tours to foster cultural shift towards low-carbon living and design. It receives over 38,200 visitors from 569 local and 86 non-local organisations in 2 years since its opening in 2012, comparatively high to other existing zero carbon buildings in the world. The active eco-office serves as a live demonstration for its green design and operation. The eco-home provides an inspiring setting for low-carbon living. Event spaces, exhibition areas, outdoor eco-cafe, constructed wetland for water recycling, demo electric vehicles (EV) charging points and the first urban native woodland of Hong Kong are provided along the circular “One Planet Living Loop”. Since its completion, it receives many local and international awards in recognition of its success in the design quality and regenerative design achievements.