Parametric Digital Twins for Preserving Historic Buildings: A Case Study at Löfstad Castle in Östergötland, Sweden

Abstract

This study showcases the digitalization of Löfstad Castle in Sweden to contribute to preserving its heritage values. The castle and its collections are deteriorating due to an inappropriate indoor climate. To address this, thirteen cloud-connected sensor boxes, equipped with 84 sensors, were installed throughout the main building, from the basement to the attic, to continuously monitor various indoor environmental parameters. The collected extensive multi-parametric data form the basis for creating a parametric digital twin of the building. The digital twin and detailed data analytics offer a deeper understanding of indoor climate and guide the adoption of appropriate heating and ventilation strategies. The results revealed the need to address high humidity problems in the basement and on the ground floor, such as installing vapor barriers. Opportunities for adopting energy-efficient heating and ventilation strategies on the upper floors were also highlighted. The digitalization solution and findings are not only applicable to Löfstad Castle but also provide valuable guidance for the conservation of other historic buildings facing similar challenges.

Figures (18)

• Figure 1: Architecture of the digital twin system.
• Figure 2: The upper photo shows a sensor box that packages an edge platform and six sensors. The lower figure depicts hardware block diagram of used components and their connections.
• Figure 3: The upper map depicts the location of Löfstad Castle, while the lower photo shows the main building of the castle.
• Figure 4: Examples of wooden objects damaged by woodworms: (a) beam of a loom and (b) a wooden ladle.
• Figure 5: A section drawing of the 3D model of the main building and an overview of sensor deployment on each floor. The basement, ground floor, first floor, and second floor are abbreviated as BF, GF, 1F, and 2F, respectively.