Buolus - Building physics design of urban surfaces for sustainable quality of urban living and environments

The objectives of BUOLUS I were the holistic development, technological expansion and practical testing of the building physics potential of urban surfaces.

As a starting point, the project brought all aspects and actors together for a structured and moderated interdisciplinary exchange. The owners and users of urban surfaces come from all sectors of urban society. Therefore, communication between the relevant stakeholders extended throughout the entire project. The identified urban challenges and demands were analyzed and translated into concrete requirements of the building physical characteristics of urban surfaces. By subsequently comparing existing and new technologies, a portfolio of innovative planning and design solutions was compiled which focuses on the functional area management of urban materials, surfaces and building components. The development of integral processes and instruments for expert planning and municipal participation was directly linked to this approach. Some results are presented below as examples:

Increased efficiency by greening buildings 

The BUOLUS sub-project “Increased efficiency by greening buildings” dealt with the (micro)climatic effects of greened urban surfaces. Unlike sealed surfaces, water can infiltrate and be retained by these surfaces, thus cooling the environment by evaporation. In the course of the project, these effects were substantiated with concrete and system-specific figures and data. In particular, it was possible to measure the differences between the green roof systems studied in terms of evaporation rate, substrate temperature and air temperature at vegetation level, which were strongly influenced by the capacity of the greened roofs to store water. The collected data are highly important when designing urban spaces, enabling the most efficient and effective greening systems to be used.

Development of a semantic 3D city model platform

As part of the BUOLUS project, Virtual City Systems developed a semantic 3D city model platform that contains wide-ranging information relevant to building physics calculation methods. This includes the city model of Rosenheim, a 3D tree register, a green space register, and the option to integrate sensor data. Furthermore, a system for mapping IFC data geometrically and semantically onto the CityGML schema was developed and implemented. Thus, the city hall of the city of Rosenheim, which was generated as an IFC model by the company Voxelgrid, was transferred to the open OGC CityGML standard and integrated into the 3D city model platform. Along with the data, geoinformation tools - such as a drawing tool for enriching the model - were also added.  

Development of integrated simulation applications based on the city model platform

Besides the 3D city model platform, a simulation application for estimating the impact of construction measures on the climate was also developed and prototyped. 3D city models serve as a basis since these already exist for many cities and therefore do not have to be modeled in a time-consuming way. Furthermore, existing buildings can be removed and plans imported or drawn in. There are four steps to the procedure. The first step is to select an area in the 3D city model platform and export the relevant objects. The second step is to calculate solar irradiance based on the 3D objects. The third step is CFD simulation using ANSYS Discovery software. In the last step, the results are visualized on the map.