In this paper we explore sustainability in interaction design by reframing concepts of user identity and use in a domestic setting. Building on our own work on everyday design and Blevis’s Sustainable Interaction Design principles, we present examples from an ethnographic study of families in their homes which illustrate design-in-use: the creative and sustainable ways people appropriate and adapt designed artifacts. We claim that adopting a conception of the user as a creative everyday designer generates a new set of design principles that promote sustainable interaction design. Author Keywords Sustainability, everyday design, users, design-in-use, appropriation, ethnography, domestic. ACM Classification Keywords H5.m. Information interfaces and presentation (e.g., HCI): Miscellaneous.