Technical State, Renovation Need and Performance of Renovation Solutions of Estonian Wooden Log Houses

Abstract

The wooden log house serves as a prevalent architectural archetype in rural regions of several Nordic and Baltic countries. To ensure the long-lasting nature of these buildings, proper maintenance is imperative. However, in order to meet the evolving expectations of residents and minimize the environmental impact, a deep renovation is currently required. To successfully achieve the goals of this renovation wave and effectively address the personal needs of the homeowners, it is crucial to develop systemic renovation solutions that can be offered through a digital renovation passport. Consequently, the purpose of this study is to identify common damages, renovation requirements, and evaluate current renovation practices. The findings will serve as a crucial resource for the development of a digital renovation passport. In our study, we utilize rural wooden log houses (comprising 208 houses, 4 years of data) as our research subject. The building elements that are most in need of renovation are the external walls, roofs, and foundations, which require renovation in 77%, 63%, and 63% of the buildings, respectively. The primary cause of damage to the vulnerable structures is excessive moisture. Additionally, decay in the foundation can be attributed to factors such as erosion of mortar, frost, insufficient plinth height, inadequate foundation depth, and inadequate moisture protection. Recommendations provided by consultants primarily focus on restoring and preserving the dwellings' original architectural appearance. As a result, they are deemed insufficient in terms of improving energy performance and indoor climate. This lack of comprehensive consultation is concerning as it fails to consider the potential for cost efficiency, minimizing disruption to occupants, and achieving a comprehensive end result. The absence of recommendations for enhancing indoor climate, energy efficiency, general living quality, and reducing the building's carbon footprint performance the necessity for such renovation solutions and the importance of educating professionals and homeowners. The study's novelty lies in the establishment of statistical probabilities for damages and their causes, as well as the assessment of renovation and maintenance needs and the quality of existing recommendations. Results are scaled to the Estonian building stock, showing the renovation need on national scale. The findings can be incorporated into the digital renovation passport, along with specific renovation goals related to a given house.