Outdoor Comfort in Cold Climates Integrating Microclimate Factors in Urban Design

Abstract: Designing urban spaces that provide outdoor comfort is an important but challenging goal in subarctic climates. An approach to urban design that is sensitive to subarctic climatic conditions is essential, but this requires effective incorporation of urban climate knowledge into urban design, which presently is impeded by several barriers. The aim of this thesis is to contribute to the knowledge of climate-sensitive urban design with a focus on outdoor comfort in cold climates. This thesis consists of a cover essay and three papers, which together address three questions: (1) What are the barriers to integrating climate factors into urban design in subarctic climates? (2) How do urban design practitioners address outdoor comfort in design process? (3) How can wind and solar considerations be integrated into the design of urban spaces? In accordance with the broad scope and interdisciplinary nature of this research, a mixed method approach was adopted, including a literature review, two interview-based studies and microclimate analysis of an urban design proposal. The study objectives were pursued in three stages corresponding to the research questions. The first stage consisted of interviews with local planners, which aimed to identify key barriers hindering the incorporation of climatic factors in urban planning in subarctic regions. Key findings include the identification of barriers related to design based, attitudinal, organisational, conceptual and technical issues. The design based issues relate to contextual difficulties for comfort design in cold climates, namely snow and low sun elevation. Attitudinal and organisational barriers include the neglect of opportunities for and challenges associated with urban liveability in cold climates, failure to exploit local knowledge and lack of engagement among local planners and politicians. Conceptual barriers relate to a lack of climate knowledge among practitioners and technical barriers relate to methods and the principles to be used in design, particularly wind comfort and snow in urban environments. The second stage centred on urban design practice, by investigating the role of comfort in the development of an urban design project in a subarctic climate. The findings of this stage showed that urban design practitioners predominantly rely on simple climate design principles and rarely use analytical tools in design. In terms of knowledge sources for urban designers, existing urban environments, work by other architects, the architects’ own experience and everyday life experiences are influential sources of understanding and inspiration. In the third stage a method to integrate outdoor comfort assessment into design is outlined and applied on a case study in a subarctic climate. The method encompasses wind comfort analysis and microclimate assessment based on solar access and wind velocity. It produces two types of result: quantitative and visual. The quantitative results include area ratios of different combinations of wind and solar conditions. Visual results are maps showing the spatial distributions of different microclimate combinations in a studied urban space, either proposed or existing. The method has proved useful for assessing relative differences in thermal comfort. Study stages highlight issues that are crucial for improving environmental comfort in subarctic climates: (1) provision of sheltering from the wind 2) maximising solar access and, (3) managing snow in the outdoor environment. In addressing these urban design issues, experimental design based research has the potential for creating and testing new design concepts. Practitioners’ reliance on simple climate design principles is also discussed. This research highlights that a more balanced application of climate design principles and analytical methods for addressing microclimate issues is required. Suggestions are also proposed to create a shift in the way outdoor comfort is addressed in practice, including clear goal definition, theory building and improving communications between research and practice. Key words: urban design, urban microclimate, outdoor comfort, subarctic climate, climate-sensitive, Kiruna