Hardware decays, software obsolesces, infrastructures sediment, devices patinate. While recent scholarship has examined longevity and sustainability, we have little empirical understanding of how things age, decay, and obsolesce and how we might approach impermanence as a resource for practice and reflection. This one-day NordiCHI'16 workshop will bring together researchers from the fields of design, HCI, and anthropology, in order to unpack the temporalities of these forms of impermanence from both theoretical and practical perspectives. The workshop aims to build a rich lexicon for the material and temporal qualities of aging, decay, degradation, and obsolescence by drawing together participants from a broad range of domains working to develop, maintain, or study systems as they age. Drawing together these different perspectives we will consider the various ways that impermanence might serve as a resource for design, use, and maintenance of long-lived technological artifacts.