Secularization has led to a decrease in the significance of religious traditions and thereby the use of churches. Accordingly, many church buildings have been converted or are used multi functionally such as the Stevenskerk in Nijmegen (NL), the monumental case study of this project. Thereby, the lifespan of
the building is extended while making use of its embodied energy.
However, the large enclosed space and the insufficient energy performance of the non-insulated building skin lead to an immense heating demand and closing of the Stevenskerk during the winter period due to unsatisfactory thermal conditions. Excessive heating results in a high energy consumption and building related CO2 emissions which are a main contributor to the ongoing climate crisis. Furthermore, the limited usability and accessibility during the cold season reduce the visibility of the national monument. This creates a lack of understanding the relevance of conserving religious heritage among citizens.
Therefore, this project investigated different renovation strategies with the aim to improve the thermal comfort in the Stevenskerk as a case-study for monumental and multi-functional churches by answering the research question «How can the renovation of the stained glass windows in combination with indoor space adaptations increase the thermal comfort in the multi-functional Stevenskerk in order to improve the accessibility of the monument all year around?»
Additional ambitions and values for the identification of suitable renovation measures were defined: the usability of the space, the reduction of the heating demand, the conservation of significant monumental values, the durability of the measures with respect to their sustainability, the proportionality of the financial investment and the acoustic and lighting conditions.
Literature review, in-situ measurements in the Stevenskerk, thermal computer simulations and physical calculations in combination with research by design enabled the identification, the development and the comparison of different renovation methods. The project introduced an evaluation framework which
resulted in a comparative overview of different window renovation and spatial adaptations strategies which is applicable for the Stevenskerk as well as for other multi-functional and monumental church buildings in the Netherlands.
According to the assessment of the introduced strategies, a renovation proposal for the Stevenskerk was developed. Based on the finding that one renovation measure for the whole building cannot fulfill all requirements, distinctive interventions for the different zones in the Stevenskerk are suggested. This enables a flexible and adaptive use according to the needs of different user groups and the space in a long-term perspective in accordance with its social responsibility as a building for the community.
To conclude, this project presents an approach on how to combine current user and building requirements with the preservation of heritage values by developing and selecting suitable renovation strategies in order to promote the functionality and visibility of the Stevenskerk and other multi-functional churches as «living heritage».