3D heatmap

Thermal images can help to uncover energy weak spots in buildings that are not recognisable to the naked eye and therefore reveal an acute need for renovation. However, the professional assessment of individual building thermography is time-consuming and expensive. In order to provide property owners an initial overview of the condition of their building, we are developing a 3D thermographic model of the entire city of Dortmund as part of the CATCH4D project. In the winter of 2024, a propeller plane equipped with thermal imaging cameras was deployed over the city to record the energy status of Dortmund’s building stock. In the recent past, other cities have had positive experiences with such thermal imaging campaigns. With CATCH4D, however, we are going a decisive step further. In the past, projects were limited to aerial photography from a bird’s eye view, which only allowed energy losses through the roofs of buildings to be recorded. The Miramap Aerial Surveys aircraft used in CATCH4D is equipped with a newly developed five-camera system, allowing for more detailed analysis. This includes the ability to take oblique thermal images to identify heat leaks on the building facades. The results of the thermographic flights are processed by the project team and linked to the 3D building model of Dortmund. Combined with other data (such as building use and building age), this creates an interactive thermographic 3D city model that provides a quick overview for free initial energy advice from the city’s Energy Efficiency and Climate Protection Service Centre (dlze).

CATCH4D attaches significant importance to the matter of data protection. A number of measures are being implemented with the objective of protecting the personal rights of citizens. During the planned thermographic aerial survey, only the roofs and facades of the buildings were recorded. It is not possible to identify vehicles or individuals in the images due to the low resolution of the images. The data obtained during the project will be used exclusively for climate protection measures and will not be passed on to third parties. The thermographic data on individual buildings can be viewed exclusively by owners. No information about other buildings is passed on. Furthermore, citizens have the option of objecting to the further processing of thermal images relating to their property by sending an email to catch4d@ils-forschung.de. In that case, the data will be deleted immediately.

The thermographic data from the aerial surveys can be obtained free of charge by interested homeowners via the dlze, probably from winter 2024/2025. At the same time, an interactive web map will be created here, which you can use to find out about energy-related issues and the status of energy efficiency in the various urban areas of Dortmund.