Thermal performance of insulation materials decreases with the passage of time. Such ageing of insulations should be considered in the design stage of buildings to keep insulation performance within the required one throughout the lifecycle of buildings. Firstly, this paper focused various factors that affect performances of insulations. The main factors for fiber insulations are moisture, vibration and microbe. The main factor for plastic insulation foams is ambient temperature that accelerates the diffusion of blowing agent. Secondly, real performances of sold new insulations and scraped old ones were measured and compared the required value by Japanese standard. Performances of some insulations were lower than standard values and performance change was detected. Finally, this paper discussed the influence of vibration on performance for fiber insulations based on the experimental data. The changes of insulation depth and thermal resistances were observed after the vibration test.
