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Redefining durability: The REWINNUSE approach to sustainable wooden windows

Special use case

The REWINNUSE project, in collaboration with M-Sora, the Slovenian Forestry Institute, and the Norwegian Institute for Bioeconomic Research (NIBIO), aimed to address the challenges faced by Slovenian joinery manufacturers in sourcing raw material, particularly spruce wood. With spruce becoming increasingly scarce and expensive, alternative wood species and innovative window design were explored.

The project tested the use of alternative wood species and demountable joints for wooden windows, aiming for environmentally friendly solutions while reducing dependence on market fluctuations.

"Tector sensors provide us with critical remote monitoring of wood moisture content, a key factor in wood durability. Their precision allows for real-time data collection across various locations, facilitating thorough scientific analysis and ensuring optimal performance and longevity of our wood products."
Boštjan Lesar
Head of the Infrastructure Centre for Preparation, Ageing and Field Testing of Wood and Lignocellulosic Materials. University of Ljubljana


Slovenian joinery manufacturers face significant challenges in sourcing spruce wood, the primary material for wooden windows. The scarcity and rising costs of spruce necessitated the exploration of alternative wood species. Additionally, there was a desire to reduce reliance on adhesives and silicone sealants, making end-of-life management more environmentally friendly and less susceptible to market fluctuations.


The REWINNUSE project addressed these challenges by researching the production of wooden windows using alternative wood species. This involved collaboration with industry partners and research institutions to test various wood species, including Scots pine, Douglas fir, Robinia, chestnut, thermally modified poplar, and waste wood from larger assortments.

To observe the performance of these alternative wood species in outdoor conditions, the REWINNUSE team decided to conduct field trials in different locations, including Norway (Fureneset and As) and central Europe (Ljubljana).

The use of Tector’s solution enabled remote observation of wood moisture content, a crucial factor influencing wood durability. Tectors sensors and dashboard analytics facilitated real-time monitoring of moisture levels across all locations, enabling researchers to download data and conduct scientific evaluations linked to specific weather conditions and other relevant properties. Smart window profile design, featuring demountable joints and dry glazing, was explored to enhance sustainability and reduce dependence on traditional materials.


The project offers valuable insights into the feasibility of using alternative wood species for window production. Field trials conducted in different locations provided data on the performance of wooden scantlings in outdoor conditions. The use of Tector’s solution facilitated remote monitoring of wood moisture content, crucial for assessing durability. 

Despite challenges like extreme precipitation, the project showcased the effectiveness of PU/acrylic coatings in maintaining moisture stability. However, uncoated samples exhibited drastic moisture content fluctuations, emphasizing the necessity of protective coatings. For instance, some samples displayed significant moisture content increases, indicating potential liquid water presence and subsequent decay. Notably, observations on a recycled silver fir scantling revealed rapid moisture content escalation, signaling delamination onset soon after field trial initiation. This underscores the importance of material selection and durability testing.

The findings of the REWINNUSE project offer practical solutions to the joinery industry, empowering manufacturers to adapt to changing market dynamics while embracing sustainable practices. By diversifying raw material sources and adopting innovative design approaches, the industry can foster resilience and minimize its environmental footprint, contributing to a more sustainable future.