Urban Microclimate Design in Hong Kong Mr CHEUNG Hau-wai, SBS Chairman, Hong Kong Green Building Council 28 April 2018
HKGBC Guidebook on Urban Microclimate Study A collaboration between HKGBC an Chinese University of Hong Kong
CONTENT 1. Conception and Background 2. Study Scope 3. Guide for Microclimate Design 4. Key for Wider Application and Collaboration 5. Application beyond Microclimate
Climate Change in Hong Kong Climate change is a critical global issue and extreme weather As mentioned in the Hong Kong Climate Change Report 2015, Hong Kong will experience increasing extreme weather events Hong Kong's Climate Change Report (2015) Adoption of urban and building designs
Climate Change in Hong Kong Hong Kong Climate Action Plan 2030+ emphasises the importance of taking into consideration urban climate High humidity and high temperatures present the greatest risk in causing heatrelated illness Hong Kong's Climate Action Plan 2030+ (2017)
HKGBC Guidebook on Urban Microclimate Study Linkage to local credit system 1. BEAM Plus embraces planning, design, construction, management, operation and maintenance of buildings 2. Microclimate design required to address Site Aspects for BEAM Plus New Buildings 3. HKGBC commissioned the Chinese University of Hong Kong 31 UMC Strategies
UMC Design Guidelines The Guidebook provides a comprehensive tool set for designers covering: Increase ventilation with site planning Increase ventilation with building design Reduce direct solar radiation Reduce surface temperature categorised into 8 approaches Increase evaporative cooling Reduce heat accumulation Provide rain protection Reduce heat release
(1) Ventilation Increase ventilation with site planning Connect Open Spaces Arrange buildings to channel wind Kai Ching Estate
(1) Ventilation Increase ventilation with site planning Building Set Back Increase permeability of building blocks Long Ching Estate
(1) Ventilation Increase ventilation with building design Permeable sky garden Hysan Place
(1) Ventilation Increase ventilation with building design to Increase building permeability - Create openings in building faç ades URA's Kai Tak Development
(1) Ventilation Increase ventilation with building design Increase ground zone air volume Green Atrium
(2) Public Health and Comfort Outdoor open space 1. 2. 1. Reduce heat discharge near pedestrian area 2. Provide shading for pedestrian activities 3. Provide water features & greenery to increase evaporative cooling 3.
(2) Public Health and Comfort Existing Building Downwashed wind captured by building height difference Increase ground zone air volume with ventilation bay or permeable podium H/W > 4 Not effective Increase ventilation with Site Planning Urban window to increase building permeability Increase ventilation with Building Design H/W < 2 effective
(2) Public Health and Comfort Existing Building Reduce Temperature by Increase albedo Reduce Temperature by Reduce thermal mass
Reduce direct solar radiation Reduce surface temperature (3) Radiation Cool materials for ground surface and green wall Shading provided by covered walkway, tree canopies and building blocks Increase albedo and sky view factor
Increase evaporative cooling Reduce heat accumulation Reduce heat release (4) Heat Water features, greenery and permeable paving Increase ventilation to carry away heat Use light-weight external shades, such as louvres or green walls
(5) Precipitation Provide rain protection Protecting pedestrians from precipitation will improve the microclimate and usability of open spaces. In designing a covered walkway, the angle of deflection from the driving rain effect should be considered.
Scientific Finding from the Collaboration University-Government-Industry Collaboration University Research Technology Education Sustainable Development Policies Incentives Public awareness Government Industry Practices Training Engagement
Our Way Forward University Collaboration among Universities, Government and Industry should ne encouraged. Government Industry
Our Way Forward General Public University Topical and Policy issues Layman s language and Illustration Government Industry Investors
Stakeholder Engagement Platform for Government Departments, Industry and Community to exchange views on issues of common interests. 1 st Stakeholder Engagement meeting (30 Sep 2016) 2 nd Stakeholder Engagement meeting (18 Apr 2017) Practitioners: Consultants Developers Government Departments (BD, HKHA, DevB, EMSD, EKEO) Universities (PolyU, HKU) NGO (PGBC)
Problems in Hong Kong Wall Effect Wall effect caused by high-rise buildings along the coast, blocking the ventilation pathways across the urban area. Isolated high rise buildings can improve ventilation of surrounding area Districts with uniform building height are worse ventilated then those with variable heights
Taking care of the health and welfare of building occupants and people on the street Mitigating and balancing the need for development and health and welfare Set Back
Microclimate Study Hong Kong s Contribution to 1) Hot and humid climate region in south east area 2) High rise and density cities
Beyond Microclimate Communal usage of precious natural resource - AIR Communal usage of 1) Open space 2) Recreational area 3) Harbour promenade 4) Walking
Provide more design options and parameters for 1) Sustainable Building Design Guidelines in APP-152 2) Planning Standard and Guidelines relating to building height [HKPSG Chapter 11]
Conclusion Social Issues Science Solutions Layman s Language & Illustrations Informed Public Opinion Informed Decisions Application beyond microclimate Application beyond Hong Kong to high density and tropical cities
HKGBC Guidebook on Urban Microclimate Study Further Studies and Applications
HKGBC Guidebook on Urban Microclimate Study The full version of the Guidebook can be accessed at: https://www.hkgbc.org.hk/eng/guidebooks.aspx. For more information, please visit HKGBC website: https://www.hkgbc.org.hk/eng/urbanmicroclimate.aspx
Thank you!