When it comes to explainability, clearly one size does not fit all. But what factors should be considered when designing novel technologies for domestic use? Based on an interdisciplinary workshop held in March 2024 in Dresden, we discuss explainability in human-machine interaction with regard to user autonomy and trust. Analysing the webs of stakeholders, we highlight the need to consider both the context of the human-machine interaction and the specific needs of the various stakeholders. Legal requirements and positions of the stakeholders are considered, as well as current research on trust in cognitive neuroscience. Both suggest that Explainability Engineering should tailor explanations to the specific person concerned. Like the workshop, the paper draws on the use case of AI-powered domestic robots and health wearables. How are explanations in that context shaped by current regulations and inhowfar do they address user needs? What role does trust play within the web of different regulations and for user reliance? How should explanations vary depending on the duration of use of the technology? Based on current cognitive neuroscience and legal research, we highlight interdisciplinary requirements for Explainability Engineering that fosters understanding and trust in a Human-Machine Interaction.