Policies for Smart and Sustainable Renovation of Urban Blocks

The objective of this chapter is to recognize the fundamental issues for the low levels of efficiency of the strategies for the energy renovation of the building stock in Greece. The regulatory framework for the energy efficiency and energy renovation is analysed, and the main policies that have been adopted for upgrading the building stock are summarized. Strategies for the energy renovation of buildings have often led to the further deterioration of the built environment as the Greek city is still characterized by the low quality of life and the low energy efficiency of buildings. A tool for assessing the overall benefits of renovation strategies at the urban block scale is presented as a means for the optimization of the efforts and profits. A smart strategy of renovation including thermal insulation, passive design, and green roofs should be context based considering urban form, urban geometry, and climate.

Study of urban microclimate conditions in a commercial area of an urban centre and the environmental regeneration potential

Urban heat island (UHI) is a phenomenon that affects the urban microclimate. Land use, urban geometry, cover materials, vegetation, the water element and human activities are the most important factors that affect the UHI. This research focused on the study and analysis of the urban microclimate of three sections of a commercial street area that differ in their morphology. The first area includes a stream near the road, the second area includes the purely commercial part of the street and the third area includes the fringes of a hill in (Thessaloniki, “Toumpa”, Gr Lampraki Street). Using the Envimet V4 program, three simulations were performed for the selected study areas for the hottest day of the previous year, August 1, 2020. The values with the largest variations in all three areas were those of relative and specific humidity and finally air speed. The air temperature was higher in relation to the suburban area (UHI) and did not show significant differences in the three study areas. This leads us to the conclusion that the urban morphology, orientation and geographical location of the three study areas played the most important role in shaping the urban microclimate. Finally, is suggested one alternative scenario for optimizing the microclimate in the most burdened area of the three.

Use and Scalability of OpenFOAM for Wind Fields and Pollution Dispersion with Building- and Ground-Resolving Topography

Complex flow and pollutant dispersion simulations in real urban settings were investigated by using computational fluid dynamics (CFD) simulations with the SST k−ω Reynolds-averaged Navier–Stokes (RANS) equation with OpenFOAM. The model was validated with a wind-tunnel experiment using two surface-mounted cubes in tandem, and the flow features were reproduced with the correct qualitative behaviour. The real urban geometry of the Parade Square in Warsaw, Poland was represented with both laser-scanning data for the ground geometry and the CityGML standard to describe the buildings as an example. The Eulerian dispersion of a passive scalar and the flow behaviour could be resolved within minutes over a computational domain with a size of 958 × 758 m2 and a height of 300 m with over 2 M cells due to the good and strong parallel scalability in OpenFOAM. This implies that RANS modelling with parallel computing in OpenFOAM can potentially be used as a tool for situational awareness on a local urban scale; however, entire cities would be too large.

URBAN GEOMETRY: CITY SHAPE AND SPATIAL LAYOUT OF 6 INDONESIAN GOVERNMENT CENTERS

Indonesia is one of the fastest-growing countries. It has about 50% of the population in the ASEAN region. The country is currently evolving and changing. The recent highlight is the country's plan to create a new capital city – moving from the megalopolitan Jakarta in the Java island to a new remote area in East Kalimantan. However, research on Indonesian cities remains very limited to provide an evidence base for planning a new capital city. A fundamental question arises: Should we plan Indonesia's new capital city following western models, or should we plan the city using traditional Indonesian city patterns? This paper examines urban geometry to show similarities and differences in the government centers in 6 Indonesian provincial capitals. They are Jakarta, Bandung, Medan, Palembang, Surabaya, and the Special Region of Yogyakarta. The six capital cities will be analyzed and categorized using street grid patterns, street centrality, built-up area and open space distribution, and government center distances. This systematic and quantitative comparison of Cities will define the underlying traits and footprint in these Indonesian cities, and the findings could be considered suggestions and guidelines for the new Indonesian capital city. This study utilizes methods and measures using automation techniques to analyze and classify Indonesian government centers based on street networks and urban geometry. The methods include land use recognition techniques using satellite images; OpenStreetMap (OSM) processed using OSMnx; GIS multi-platform applications to run the spatial analysis. On the one hand, the study should contribute to urban design and capital city planning in Indonesia. On the other hand, it should provide methods for comparative studies of cities in developing countries.