Positive Development: Design for Urban Climate Mitigation and Ecological Gains
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Stream 5 – Pushing the Boundaries: Net Positive Buildings (SB13): CaGBC National Conference & Expo, Vancouver BC, June 4-6, 2013 Positive Development: Design for Urban Climate Mitigation and Ecological Gains B.C. Renger Queensland University of Technology, Australia J.L. Birkeland University of Auckland, New Zealand D.J. Midmore Central Queensland University, Australia ABSTRACT: Positive Development (PD) theory reframes sustainable planning, design and decision making within an open systems and eco-positive framework. PD posits that buildings can go beyond regeneration and resilience over their life cycle to increase the net ecological base beyond pre-industrial conditions through, among other principles, building-generated eco- services. As architects and a biologist, as well as with substantial inter-disciplinary expert support, we applied PD concepts, methods and tools to a building design to test whether a future architecture could mitigate the urban climate while increasing environmental quality, ecological carrying capacity and access to the means of survival. Given data and time constraints, this paper only calculates when the building could potentially amortize its embodied and operating energy, water usage and carbon emissions. The conclusion is that buildings that support substantial ‘ecological space’ for soil, vegetation and micro-biodiversity could potentially make net positive contributions to both humans and nature. 1. INTRODUCTION The paper documents an analysis that was undertaken to determine if a building could sequester carbon equivalent to that emitted in its construction and operation by building integrated vegetation, and generating energy and water surplus to usage. The potential net positive ecological impacts (relative to pre-industrial conditions) were also considered, but could not be included in this short paper. 1.1 Background Cities, and the built environment generally, are not yet sustainable by any definition. Their designs do more harm than good to the life support system, and exacerbate most environmental problems and ‘natural’ disasters (e.g., flooding, earthquakes, urban heat island). Conventional sustainable development standards and tools do not yet contemplate construction that makes measurable, net positive contributions to ecological sustainability. Leading-edge positions aim to leave the environment better than under current site conditions (Lyle 1994, DuPlessis 2012, Cole 2012). However, remediation or regeneration of the environment is not enough, as the real world context has changed dramatically. Given rapidly diminishing resources, an exploding population, increasing disparities of wealth and biodiversity losses (the food chain), built environment design must do far more than regenerate the ecology on the construction site. A fundamental paradigm shift is necessary from what is now called ‘sustainable development’ to net Positive Development (PD). PD theory provides a ‘positive’ re-formulation of policies, decision systems, design concepts, models, analyses, methods and metrics (Birkeland 2008). It is virtually the opposite of the ‘negative’ dominant paradigm (DP). Simply put, PD 83 Stream 5 – Pushing the Boundaries: Net Positive Buildings (SB13): CaGBC National Conference & Expo, Vancouver BC, June 4-6, 2013 holds that to be sustainable, given existing ecological and social deficits and population growth, built environments must not only add social, cultural and economic value, they must give back to nature more than they take (Birkeland 2003). This means increasing ecosystem carrying capacity and the public estate (access to means of survival and well being). Although cities are a major cause of sustainability issues (Girardet 1996) they can be converted into drivers of sustainability. Cities can provide the space and infrastructure to increase passive or natural systems and services and replace many non-renewable resources, at no net loss of space for human activities and functions, as the present design shows as one example. The PD Sustainability Standard is defined as pre-industrial ecological conditions in the bioregion and/or site (on a floor area or ecological footprint basis) as a benchmark for the net positive impacts that a development would need to provide in order to reimburse the future for past and present impacts through increases in the ecology, ecosystems and eco-services [Appendix 1]. Eco- services are nature’s services, like clean air, water, food, carbon sequestration and oxygen production, but include the intrinsic values of nature (Cf. Birkeland 2009 a & b for examples). Eco-positive design criteria follow logically from this benchmark (Birkeland 2008, pp. 257-8) and were applied to this project. 2. THE PROJECT Given the ongoing impacts of cities and construction processes, retrofitting cities is essential to sustainability. However, some new buildings will always be necessary and they are more challenging in terms of PD criteria. Therefore, this exploratory research applied some PD methods, tools and metrics to a new building design. An extensive literature search did not reveal a modern building that attempts to increase the natural life support system or access to the means of survival in absolute terms. While a demonstration project for net PD was designed for a site in Canberra, Australia (ANSI 2007), it was suspended by the economic downturn of 2008 [Appendix 4]. The present research was based on a site in Brisbane, with a subtropical climate and therefore a very different design. The research question was whether architecture could mitigate the urban climate and increase the natural life support system in measurable ways. This research quantifies some of the photosynthesis, air and water treatment functions of extensive integrated vegetation. This paper, however, is limited to carbon emissions, water cycles, embodied and operational energy and not ecological aspects or carrying capacity (forthcoming). The quantitative analysis found that a building can conceivably reverse these impacts through passive solar and renewable energy systems that exceed resource autonomy and by providing substantial ‘ecological space’ (see below). The study concludes that a conventional architecture cannot achieve this Sustainability Standard. A new eco-positive paradigm for environmental planning, design and assessment is required. Inter-disciplinary integration and collaboration are an essential part of any sustainable design process. The positive and negative impacts relevant to water, carbon and energy were assessed with the assistance of research partners with different specializations. The authors are grateful for the support and expertise of many firms and individuals for their expertise, including: Environmental Scientist Dan Potter of Chenoweth Environmental Planning on pre-clear vegetation communities; Patrick Campbell of WSP Built Ecology on energy balance and photovoltaics; Dominic Xavier and Elena Bogdanova of Sustainable Solutions International (SSI) on water balance; Delwyn Jones, Evah Institute, for life cycle assessment; architects including Peddle Thorp Architects, Brisbane for constructive feedback; Department of Environment, Research and Development for pre-clear vegetation datasets, historical surveys, maps and other information; Dr. Mirko Guaralda of the QUT in Brisbane, Australia, for advice. None of the above is responsible for the content of this paper. 84 Stream 5 – Pushing the Boundaries: Net Positive Buildings (SB13): CaGBC National Conference & Expo, Vancouver BC, June 4-6, 2013 2.1 Site selection and analysis: PD seeks to identify urban projects that can address urban social and ecological shortfalls and overshoots, and benefit the society and ecology as well as investors. In this case, the selected site is a 28 hectare remnant of land which was, prior to the establishment of Exhibition Grounds, used since 1862 by the Queensland Acclimatisation Society to promote the introduction of economically useful ‘foreign’ plants, materials and animals. This site was suitable for increasing indigenous ecosystems through physical development. The proposed use was a sustainability research and learning hub to facilitate collaboration between industry, researchers and the community on sustainability issues. An Interpretive Centre, in proximity to the Brisbane CBD, could also catalyze the social and economic revitalization of this derelict, transport-dominated and fragmented area. Therefore, a wide range of social, educational and cultural uses and values were incorporated in the design. Ecological Transformation Analysis was applied as one of 12 PD planning analyses designed to address some information gaps that would be required for ethics-based planning and design [Appendix 3]. It maps the original site ecology to guide the reintroduction of endangered species and appropriate vegetation, and to increase environmental flows (Cf. Sanderson 2009). Quantitative measures of on-site water and original rainfall data were available from historical maps and surveys and the Bureau of Meteorology. No water bodies currently exist on site, but the earliest available survey (1863) shows a creek and waterholes. This guided the location of proposed streams and biotopes and provided useful parameters for increasing appropriate soil, water and ecosystems. Indigenous plants indicate what ecosystems may be successful on the site. Predominantly three broad vegetation communities existed on this site before European settlement. Their biodiversity status is all ‘of concern’