Kristina Kiesel

Empirical and Computational Issues of Microclimate Simulation

The dynamic variability of weather conditions and complex geometry and semantics of urban domain impose significant constraints on the empirical study of urban microclimate. Thus, numerical modeling is being increasingly deployed to capture the very dynamics of urban microclimate. In this context, the present paper illustrates the basic processes of calibrating and preparing a numerical model for the simulation of the urban microclimate.

Methodologies for UHI Analysis

A central strand of research work in the realm of urban physics aims at a better understanding of the variance in microclimatic conditions due to factors such as building agglomeration density, anthropogenic heat production, traffic intensity, presence and extent of green areas and bodies of water. The characteristics and evolution of the urban microclimate is not only relevant to people’s experience of outdoor thermal conditions in the cities. Higher air temperatures also exacerbate discomfort caused by the overheating of indoor spaces and increases cooling energy expenditures. It can be argued that the solid understanding of the temporal and spatial variance of urban microclimate represents a prerequisite for the reliable assessment of the thermal performance of buildings (energy requirements, indoor thermal conditions). In this context, the present treatment entails a three-fold contribution. First, the existence and extent of the UHI phenomena are documented for a number of Central-European cities. Second, a comprehensive assessment of the effectiveness of UHI mitigation measures in these cities is described that is conducted using advanced numeric modelling instruments. Third, a systematic framework is proposed to identify a number of variables of the urban environment that are hypothesized to influence UHI and the urban microclimate variance. These variables pertain to both geometric (morphological) and semantic (material-related) urban features.

Pilot Actions in European Cities – Prague

This chapter describes results of pilot actions in Prague. Two different pilot areas were selected (Legerova street and Bubny-Holesovice quarter) with different modelling approach. Finally, the Green belt around Prague is studied as well. Different scenarios are tested and their results discussed. The matter of air quality is also analysed.

Including Sustainability Criteria in Architectural Completion: A Critical Case Study of Current Practices

The Architectural competition announcements in Austria, as well as in most other European countries, regularly mention sustainability as a fundamental factor for decision-making. The consideration of energy performance, environmental performance of materials (embodied energy, reuse or recycling potential, toxicity), natural ventilation, and daylight availability are typically mentioned in the list of project requirements. In this context, the present contribution considers three actual architectural competition cases. Thereby, we investigated the kinds and depth of sustainability-related criteria as included in the competition announcements (e.g., hard versus soft requirements, qualitative versus quantitative benchmarks) . Moreover, we explored the level to which competition entries actually responded to the sustainability-related competition criteria. Thus, the submission materials (project narratives, posters and simple calculations if existing) available to the jury were analysed in detail. Toward this end, two approaches were selected: A qualitative approach focused on the use of certain terminology within the documentation of the projects. The second approach took certain numeric indicators into consideration such as heating demand and OI3 Index (sustainability). In those cases where the indicator values were not submitted by the participants, they were calculated by the authors based on available documentation. The study implies the need for a reconsideration of the process of formulating architectural competitions and evaluating the related submissions. It appears that currently the sustainability-related requirements in competition documentations do not lead to entries, which provide sufficient information for accountable jury evaluation. Rather, alternative and/or additional comprehensive indicators of sustainability and ecological performance must be included in a clear and systematic fashion in architectural competition narratives.