This contribution deals with the further development and evaluation of sustainability integration in the product development approach of Integrated Design Engineering (IDE). In order to focus more strongly on sustainability in IDE, sustainability is no longer considered as a single product attribute in IDE, but as an evaluation attribute depending on the other product attributes product gestalt, functionality, usability, producibility, availability, and maintainability. An evaluation method will be developed that includes sustainability-related evaluation criteria for the individual product attributes of the IDE. These sustainability criteria (environmental and social criteria) were determined in student projects of the IDE Master’s degree program and then summarized in a maturity degree for each product attribute using a simple maturity model analogous to ISO/IEC 33020-2, which is usually used for process evaluations. This Sustainability Maturity Model thus serves as a practical and fast evaluation tool that can be used during product development in student projects, SMEs and/or small development teams to determine the maturity degree of a product's sustainability and, if necessary, to document sustainability-related progress in the ongoing product development process.