Green Roof Retrofit

Sara Wilkinson - Associate Professor in Property and Construction, University of Technology, Sydney. Sara has a combination of professional industry and academic experience spanning more than 30 years. Sara's research focus is building adaptation within the context of sustainability, and represents areas of professional practice prior to becoming an academic. Her PhD examined building adaptation and the relationship to property attributes, whilst her MPhil explored the conceptual understanding of green buildings. Sara is a member of the RICS Oceania Sustainability Working Group. She is the International Federation of Surveyors (FIG) Vice-Chair of Commission 10 "Construction Management & Construction Economics". Sara is also author of eight books/book chapters and was awarded the RICS COBRA Conference Best Paper Award in 2012 for her paper. The increasing importance of environmental attributes in commercial building retrofits. RICS COBRA Las Vegas USA. September 2012.Tim Dixon - Chair in Sustainable Futures in the Built Environment, University of Reading Tim joined the School of Construction Management and Engineering, University of Reading in 2012. He was formerly was Director of OISD and Professor of Real Estate (2005-2012) at Oxford Brookes University. He is former Director of Research at the College of Estate Management, Reading (1998-2005). With more than 25 years' experience of research, education and professional practice in the built environment he is a fellow of the RICS and of the Higher Education Academy; a trained RICS APC assessor; and a former member of SEEDA's South East Excellence Advisory Board. He is also a member of the editorial boards of four leading international real estate journals (Journal of Property Investment and Finance, the Journal of Property Management, the Journal of Building Appraisal and Journal of Sustainable Real Estate); a member of the Advisory Board for Local Economy-; and a member of the review panel of the RICS Research Paper Series. He is a regular contributor to professional journals such as Estates Gazette and he is a regular columnist with Newzeye's 'Property Forecast'. He is also a member of the CORENET Sustainability Working Group and RICS Sustainability Group. In 2009 he was awarded Honorary Fellow status of the Institute of Green Professionals, which seeks to recognise pre-eminent individuals who exemplify academic and/or professional excellence, and serve as examples of scholarship and leadership for the global sustainability community and the public. He was formerly a member of the Oxford Futures Development Group, and carried out a peer review of the Qatar National Plan, funded by Ministry of Qatar (2010). He has recently worked on a range of funded sustainability-based research programmes, including European Investment Bank EIBURS (social sustainability and urban renewal), RICS (sustainability indicators - 'Green Gauge' project), and RICS Education Trust/Kajima Foundation ('A Comparative Study of UK-Japan Brownfields'). He also contributed to the evidence review for the DIUS Foresight Land Use Futures programme. He is currently working on the RICS 'Green Gauge' project and 'Low Carbon UK Cities' projects and EPSRC RETROFIT 2050 project (a major four year funded programme of research). He is also working in the University in a consultancy role with a number of key players in the property sector to operationalise the measurement of social sustainability in property development and regeneration projects, building on the OISD's EIB work, which he developed and led. The EIB work led to the book, ‘Urban Regeneration and Social Sustainability’ in which he was principal co-author.

• Notes on Editors xNotes on Contributors xiForeword xivAcknowledgements xviChapter 1 Building Resilience in Urban Settlements Through Green Roof Retrofit 11.0 Introduction 11.1 Background and Context: Green Infrastructure 21.1.1 Green Roofs 41.2 Extensive and Intensive Systems 51.3 Valuing Green Infrastructure and Wider Economic Benefits 51.4 Measures of Greenness in Cities and the Growing Market for Green Roofs 71.5 A Growing Global Market for Green Roofs 71.6 Overview of the Structure of the Book 81.7 Conclusion 12References 12Chapter 2 Technical and Engineering Issues in Green Roof Retrofit 142.0 Introduction 142.1 Technical and Engineering Considerations 152.2 Roof Structure and Covering Typologies 152.2.1 Pitched Roof Structures 152.2.2 Pitched Roof Coverings 162.2.3 Flat Roof Structures 182.2.4 Flat Roof Coverings 192.2.5 Other Roof Designs 202.2.6 Green Roof Modular Systems 202.3 Available Space 212.4 Structural Capacity 212.5 Waterproof Membranes and Insulation 232.6 Drainage 242.7 Heritage 242.8 Green Roof Access 242.8.1 Access for Maintenance 252.8.2 Temporary or Permanent Access Strategies 252.8.3 Maintenance Frequency 262.9 Other Issues 262.10 How to Determine Which Green Roof Type is Best Suited to Different Structures 262.11 Illustrative Case Studies 272.11.1 Australia – Surry Hills Library and Beare Park, Sydney 272.11.2 Brazil 302.11.3 1214 Queen St West, Toronto, Ontario, Canada 332.11.4 107 Cheapside, London, UK 342.12 Conclusions 35References 36Chapter 3 Green Roof Retrofit and the Urban Heat Island 373.0 Introduction 373.1 Defining the Urban Heat Island 373.1.1 UHI Impacts on Environment, Society and Economy 393.2 Microclimatic Effects of Rooftop Greening 403.3 Green Roof Cooling Mechanisms 433.4 Green Roof Retrofit for UHI Mitigation – Defining the Boundaries 453.4.1 Roof Availability and Suitability 453.4.2 Design Considerations – Intensive Versus Extensive 463.5 Green Roof Retrofit for UHI Mitigation – Developing the Model 473.5.1 Overview of Methods 473.5.2 Modelling Roof Availability and Suitability 483.5.3 Modelling Thermal Performance 493.6 Model Implementation – Evaluating Sydney’s Surface and Canopy]Layer Heat Islands 503.7 Green Roof Retrofit for UHI Mitigation – Model Implementation 553.8 Conclusions – Where to from Here? 573.8.1 Limitations of the Research and Opportunities for Further Work 58References 59Chapter 4 Thermal Performance of Green Roof Retrofit 624.0 Introduction 624.1 Green Roof Retrofit and Thermal Performance 634.2 Research Methodology 674.3 Case study: Rio de Janeiro and Sydney 684.3.1 Rio de Janeiro Case Study 694.3.2 Sydney Case Study 744.3.3 Evaluation of Rio de Janeiro and Sydney Cases 784.4 Conclusions 80References 82Chapter 5 Stormwater Attenuation and Green Roof Retrofit 855.0 Introduction 855.1 The Problem of Pluvial Flooding 865.2 Specifications for Stormwater Roofs and Issues for Retrofit 885.2.1 Technical and Physical Issues in Retrofit 885.2.2 Estimating Runoff Reduction 895.3 Modelling for City]Scale Stormwater Attenuation 905.3.1 Melbourne, Australia 925.3.2 Newcastle]upon]Tyne, UK CBD Database 955.3.3 Melbourne and Newcastle Runoff Estimation 975.4 Assessment of Retrofit at a Building Scale 995.4.1 Portland Ecoroof Programme 1015.5 Conclusions – Where to Next? 102References 103Chapter 6 Biodiversity and Green Roof Retrofit 1066.0 Introduction 1066.1 What is Biodiversity? 1086.2 Green Roofs for Vertebrate Conservation 1096.3 Green Roofs for Invertebrate Conservation 1106.4 Conclusions 1126.4.1 Designing Biodiverse Green Roofs 113References 115Chapter 7 Planting Choices for Retrofitted Green Roofs 1187.0 Introduction 1187.1 Ecosystem Services Delivery By Green Roofs: The Importance of Plant Choice 1207.2 Plant Species Choice and Building Cooling/Insulation 1207.2.1 Plants and Cooling – Basic Principles 1207.2.2 Plant Species Choice and Summer]Time Surface Cooling 1237.2.3 Plant Species Choice and Winter]Time Insulation 1297.3 Plant Species Choice and Stormwater Management 1307.4 Greater Plant Variety can Enhance Urban Biodiversity 1337.5 Plant Choices and Particle Pollution Mitigation 1347.6 New Plant Choices and Adaptation of Current Green Roof Systems 1347.7 Conclusions and Future Work 135References 136Chapter 8 Green Roof Retrofitting and Conservation of Endangered Flora 1408.0 Introduction 1408.1 Biodiversity Conservation – a Strategic Overview 1418.2 A Review of Green Roofs in Habitat Conservation 1438.3 Knowledge Gaps and Further Research 1468.3.1 A Research Programme for Conserving Endangered Species on Green Roofs 1478.3.2 The Endangered Community of the Eastern Suburbs Banksia Scrub 1478.4 A Model Research Design for Species Conservation 1498.4.1 Extensive or Intensive Roofs? 1498.4.2 Research Objectives 1508.4.3 Guiding Principles for ESBS Regeneration 1528.4.4 Preparatory Steps 1528.4.5 Monitoring 1538.4.6 Expected Outcomes 1538.5 Conclusions 154References 154Chapter 9 Urban Food Production on Retrofitted Rooftops 1589.0 Introduction 1589.1 Green Roof Retrofit and Urban Food Production 1599.2 Stakeholders and Urban Food Production 1619.3 Contamination and Air]Quality Issues 1629.3.1 Types of Pollutant 1639.3.2 Most Urban Soils are Contaminated 1649.3.3 Do Contaminants Accumulate in Urban Crops? 1659.3.4 Mitigating Urban Crop Contamination 1679.3.5 Urban Gardens and Air Quality 1699.4 The Research Design and Methodology 1709.4.1 Case Studies 1719.4.2 Gumal Student Housing 1719.4.3 Science Roof 1739.4.4 Vertical Gardens 1759.4.5 Results and Interpretation 1769.4.6 Findings 1809.5 The Carbon Footprint of Food Grown on Demonstration Beds 1809.6 Potential Reductions in Carbon Footprint 1819.7 Conclusions 183References 183Chapter 10 Social Aspects of Institutional Rooftop Gardens 18910.0 Introduction and Objectives 18910.1 Social Aspects, Productivity and Sustainability Potential of Rooftop Gardens 19010.2 Methodology 19310.2.1 Comparative Analysis of Eight University Rooftop Garden Case Studies 19510.2.2 Semi]Structured Interviews with UTS Roof Gardening Club 19510.2.3 107 Projects Rooftop Garden: A Sensory Ethnography 19610.3 Main Findings 19710.3.1 Comparative Analysis of Eight Rooftop Gardens in Universities 19710.3.2 Qualitative Analysis of UTS Roof Gardening Club Semi]Structured Interviews 19810.3.3 107 Projects Rooftop Garden, Sydney 20510.3.4 St Canice Kitchen Garden, Kings Cross, Sydney 20810.4 Recommendations, Discussions and Conclusions 209Acknowledgement 212References 212Chapter 11 Cool Roof Retrofits as an Alternative to Green Roofs 21611.0 Introduction 21611.1 What is a Cool Roof? 21611.2 Background – How does a Cool Roof Work? 21711.3 Cool Roof Studies and Measurements 21711.4 The Experiments 21811.4.1 Results 21911.4.2 Other Residential Building Typologies 22811.4.3 Impact of CRP on PV Energy Generation 23111.5 Conclusions 23211.5.1 Negative Impacts of Cool Roofs 23211.5.2 Green Roofs Versus Cool Roofs 23211.5.3 Cool Roofs and Retrofits 23311.5.4 Barriers and Stakeholders 233Acknowledgements 233References 234Chapter 12 Looking to the Future 23512.0 Introduction 23512.1 City]level Actions: Basel and Paris 23512.2 City]level Actions: Requirements or Inducements? 23712.3 Tools and Information Sources 24012.4 Green Roofs: The Big Picture of GI and Future Developments 24112.5 Recognising the Multiple Benefits of Green Roof Retrofit 24312.6 Overall Conclusions 244References 245Appendices 247Appendix 1: A Checklist for Appraising the Suitability of an Existing Roof for Green Roof Retrofit 247Appendix 2: Checklist for Designers of Biodiverse Green Roofs 250Appendix 3: Tools, Information Sources and Mapping/GIS for Green Roofs – Some Examples 253Index 257