With an increasing height of timber buildings, the challenge is growing to provide moisture-safe conditions for the expected lifetime of building envelopes. Tall buildings are particularly exposed to high wind pressures combined with driving rain. Additionally, large-scale buildings require longer times of construction in which the structural elements are especially exposed to moisture. Last but not least inspection, maintenance and repair possibilities are limited in high rise structures. Compared to fire safety and static demands, the risk of failure due to moisture today is dramatically underestimated in planning and building processes and in quality management. Although statistics of construction damages clearly show the high amount of moisture related failure of the building shell resulting in an immense economic loss that is estimated to 3 – 5% of total annual investment in new buildings in Europe. Experts guess that this range may exceed in future due to higher insulated, more complex and enclosures that are more sensitive. This may also lead to an image risk for timber buildings, if damages will increase in future. Therefore ‘semi-probabilistic safety concepts’, similar to those in static calculations, are necessary to prevent negative consequences caused by inappropriate reaction of construction to climate exposure. The main objective of the project is to facilitate the confident design of durable and therefore cost-effective design solutions for tall timber facades. The risk-based RiFa-Tool taking into account exposure and vulnerability of façade systems will enable the moisture-safe design consistently. Project results: The straightforward achievement is the identification of damage scenarios related to human error and construction processes, which is closely related with the identification of building’s architectural design and detail construction related risk areas. In risk model part A, a scientific approach, more suitable for research and development of components is developed. The performance assessment process employed as part of this RiFa-Tool A. The entire probabilistic-based approach is implemented in the form of a seamless and integrated parametric workflow. By means of efficiently combining the MATLAB®, Python and XML codes. The seamless workflow enables an efficient conversion of the variability of the input parameters into a probabilistic representation of the output. The user of RiFa-Tool B can choose between two tools, depending on how much information he has about the details. If the frequency of failure and potential repair costs are known (or can be guessed accurately enough) the so-called event tree can be used. If this is not the case, the so-called reversed approach can still find a threshold from which the user recommends one or the other solution. The event tree method can be used as system analysis tool and for consequence identification. Additionally the event tree method gives a structured and generalized approach to solve different problems on joints or connections of components, which are highly prone to moisture leakage. It is a very good way to integrate load bearing, fire-safety, and sound transmission together with the moisture safety. The main advantage if its use is its flexibility; instead of solving problem with many different catalogues with details, which are not related to each other or already outdated. Under explicit event tree queries for failure, the tool will be able to serve work preparation and quality control. Hence, it will serve the improvement of quality in production, mounting, and avoidance of human error.      «

With an increasing height of timber buildings, the challenge is growing to provide moisture-safe conditions for the expected lifetime of building envelopes. Tall buildings are particularly exposed to high wind pressures combined with driving rain. Additionally, large-scale buildings require longer times of construction in which the structural elements are especially exposed to moisture. Last but not least inspection, maintenance and repair possibilities are limited in high rise structures. Com...     »