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Vacuum insulation panels (VIPs) represent a high performance thermal insulation material solution offering an alternative to thick wall sections and large amounts of traditional insulation in modern buildings. Thermal performance over time is one of the most important properties of VIPs to be addressed, and thus the ageing effects on the thermal properties have been explored in this work.Laboratory studies of ageing effects are conducted over a relatively limited time frame. To be able to effectively evaluate ageing effects on thermal conductivity, accelerated ageing experiments are necessary. As of today, no complete standardized methods for accelerated ageing of VIPs exist. By studying the theoretical relationships between VIP properties and external environmental exposures, various possible factors for accelerated ageing are proposed. The factors that are found theoretically to contribute most to ageing of VIPs are elevated temperature, moisture and pressure. By varying these factors it is assumed that a substantial accelerated ageing of VIPs can be achieved.Four different accelerated ageing experiments have been performed to study whether the theoretical relationship may be replicated in practice. To evaluate the thermal performance of VIPs, thermal conductivity measurements have been applied.The different experiments gave a varying degree of ageing effects. Generally the changes in thermal performance were small. Results indicated that the acceleration effect was within what could be expected from theoretical relationships, but any definite conclusion is difficult to draw due to the small changes. Some physical changes were observed on the VIPs, i.e. swelling and curving. This might be an effect of the severe conditions experienced by the VIPs during testing, and too much emphasis on these should be avoided.

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External Thermal Insulation Composite Systems (ETICS) with Rendering are widely used in both rehabilitation and new building projects, even in areas with harsh climates such as the western regions of Norway. However, we have seen extensive cases of defects involving such systems. This paper presents a comprehensive review of Norwegian experiences regarding the durability of ETICS on walls. The presented results are based on building research conducted by SINTEF 61 as well as 30 accelerated climatic laboratory experiments over the last 25 years on similar façade systems. These systems generally perform satisfactorily if thoroughly designed and carefully erected. However, according to the survey, the systems are not very robust. Even minor errors in design techniques and/or craftsmanship can lead to rendering defects. The investigations clearly show that ETICS is particularly vulnerable when exposed to severe driving rain conditions. ETICS provides only a single-stage protection against wind and precipitation and do not dry effectively after being wetted. Hence, the resultant cracks and other rendering weaknesses could be disastrous, enabling moisture to penetrate into the thermal insulation and the wall behind. In areas with heavy driving rain, we recommend façade solutions erected in accordance with the principle of two-stage tightening rather than ETICS.

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