Designing for Sustainability, Is Net Zero Energy & Zero Carbon Buildings achievable in Hong Kong?

1. Designing for Sustainability, Is Net Zero Energy & Zero Carbon Buildings achievable in Hong Kong? Student: Edward Shen (1155011481) Supervisor: Edward Ng, REN Chao 15 December 2012

2. Where do we get carbon emissions? • Direct emissions • Stationery – boilers, turbines • Mobile – road / air transport • Equipment / System operations – refrigerators, air-conditioners 2. Indirect emissions – electricity, towngas 3. Other indirect emissions – waste, sewage

3. What is carbon footprint? A carbon footprint measures the total green house gas emissions caused directly and indirectly by a person, organization, event or product, usually expressed in equivalent tons of carbon dioxide.

4. What are appropriate definitions for ZEB and ZCB? • ZEB definition – Zero Energy building is “a building, which on an annual basis, use no more energy there is provided by on-site renewable energy sources”. • ZCB definition – A zero carbon building should achieve zero emissions over the full life cycle ie. emissions before use (embodied emissions), during use (from building-incorporated services and appliances, and maintenance and refurbishment) and after use (deconstruction and recycling).

5. What are appropriate definition for ZEB and ZCB? • What is then the difference between ZEB and ZCD? Zero Energy Design differs from Carbon Neutral Design in that it is more concerned with the reduction of the operating energy requirements for a building, focusing on the eventual use of only non-fossil fuel energy. It is obvious then the burning of any type of fuel, be it renewable results in emissions which is one of the significant differences of the goals for Zero Energy versus Carbon Neutral / Zero Carbon.

6. Characteristics & Strategies for Zero Energy and Carbon Neutral buildings The focus of this study is confined to essentially energy consumed by buildings and building associated carbon emissions, and subsequent analysis be focused on the context of Hong Kong only. There is carbon associated with all aspects of a building, hence holistic carbon neutral design is looking to reduce the carbon emissions associated with all aspects of the project. Of foremost interest to this study is the carbon connected to operational energy ie energy sources to heat, cool and light buildings which are essentially fossil fuel based and accountable for 70% to 80% of the CO2 footprint of buildings (direct emission from fuel combustion and indirect emission from electricity generation.)

7. Hong Kong’s first ZCB works on 3 strategies: 1. Passive Approach • Local micro climate – form / orientation • Nocturnal ventilation • Shading • Daylighting • Sloping roof + PV system • Greenery & landscaping • Materials

8. 2. Energy Efficient Active Systems Hong Kong’s first ZCB works on 3 strategies: • Cross ventilation & HVLS fans • Under floor air supply, radiant cooling systems and desiccant dehumidification • Energy Cascade Concept • Other systems deployed

9. 3. Energy Positive / Renewable Energy Hong Kong’s first ZCB works on 3 strategies: • Photo-voltaic panels • Biodiesel

10. Does Hong Kong’s first ZCB point any direction for Carbon Neutral design in Hong Kong? What hurdles then need to be overcome for universal application of ZCB in Hong Kong? • No control on adjacent site development rights • Wind corridors, wind direction, sun radiance, humidity & temperature • Reliance on predetermined layout roof shape, heat stack effect & open plan with high ceiling voids • Low impact to district environment • Reliance on renewable form of energy, (biodiesel) for offset • High Cost • Biodiversity So have to make own attempt to find out if ZCB can be attainable in Hong Kong on a meaningful scale?

11. 1st failed attemptIndustry’s answer is “No cannot do it” May be the answer for Hong Kong is not on individual building site basis but on scale of district or territorial basis?

12. 2nd failed attemptWrong, all of Hong Kong’s Country Park and forested land cannot offset carbon emissions from even existing buildings. To achieve net carbon neutrality for all the emissions given out by buildings we shall need 110,000 hectares of land to accommodate an equivalent of over 1 billion trees before we can do the offset. Hong Kong currently has total green planted space (inclusive of trees, shrubs and grassland) of just under 75,000 hectares, out of which forested land occupies barely 25,000 hectares. It is obvious, despite 40% of HK’s land area is designated as Country Park we do not have enough carbon credit from green space to even off-set the carbon emissions from our existing buildings.

13. 3rd failed attemptGiven the fact that we cannot rely on our Country Parks to provide carbon off-set.What may be the desired mode of development density to achieve Carbon Neutrality?

14. Conclusion Carbon neutrality for all Hong Kong buildings is too ambitious a target and the issue cannot be looked at just from within the confines of our city, and if zero carbon is indeed an ultimate target, it may only be resolved on a still larger context of greater China and its national carbon emissions policy and the Asia region. What is Hong Kong Government’s announced carbon reduction targets (if not for Carbon Neutrality)?

15. A new goal post position? China, while not classified under developed countries, has nonetheless set a target for year 2020 to realize a carbon emission reduction of 40%-50% on the baseline emission level of 2005. In 2007, the HKSAR Government pledged to reduce energy intensity by at least 25% (2005 baseline) by 2030. In May 2010, the HKSAR Government announced that it would follow China’s target of reducing carbon intensity by around 45% by 2020 (2005 baseline).

16. Hong Kong’s carbon emissions are generated primarily from: • Power sector-accountable for 60% of Hong Kong GHG emissions • Change of fuel mix • Nuclear and other renewables • Building, sector • Green building standards • Education • Energy-efficient consumer products 3. Set absolute emission standard

17. Design for Sustainability • What are the essential elements for a sustainable building? • Energy • Roads & Transportation • Water / wastewater / stormwater • Waste (garbage, recycling, composting) • Greenspace • Does reduction of carbon dioxide and other GHG emissions all it takes for sustainability?

18. Design for Carbon Neutrality vs Design for Sustainability – CND a subset? • Carbon Neutral Design carries specific focus on carbon reduction versus the very broad and holistic mandate of Sustainable Design. • The three pillars of Sustainability: • Environmental Sustainability • Economic Sustainability • Social Sustainability

19. How Sustainability is played out in Hong Kong? • When we talk about high-density living, Hong Kong can boast of a population density of 46,000 people per km2 in the densest area, since 50% of our population has to cram into 21% of Hong Kong’s urban land area. Is this a sustainable urban form projecting into the future? • Close proximity between living, entertainment, shopping and transport bring convenience for the residents and reduced energy use for commuting from facility to facility, such convenience and thus time saved has either been accepted and adapted socially as a trade-off for privacy. It also appears Hong Kong’s aging population seems to have an apparent preference to live in high-rise towers in the urban centre to enjoy a better view and fresher air, and social interaction with neighbors and community at large. • It is imperative that government and all stakeholders should see sustainability as which requires both physical aspects (such as buildings and site) and non-physical aspects (such as use of the building and management systems) to work together in an efficient and integrated way to achieve sustainable development objectives.

20. According to the World Commission on the Environment and Development, 1987, Sustainability was described as a state in which humankind is living within the carrying capacity of the earth, meaning that the earth has the capacity to accommodate the needs of existing population and is also able to provide for future generations.As we humankind has now upset the intricate balance of the ecosystem which exceeded the carrying capacity of the earth, hence the world community needs to make strong and concerted effort to return to within that carrying capacity. What’s Next?

21. Thank you