This study addresses the need to enhance the quality of Intelligent Environments, recognizing their unique characteristics and the absence of adequate guidance on quality management during development. It pursues three primary objectives: proposing a novel quality-in-use model, presenting an enhanced version of the User-Centered Intelligent Environment Development Process, and reporting on the application of these approaches through a multiple case study. To embed quality into systems, we advocate for the integration of quality characteristics from ISO/IEC 25000 standards with functional requirements. Stakeholders collaboratively define targets using measures from quality standards, and metrics enable early problem detection and resolution during development. The proposed quality-in-use model provides an insightful and objective perspective on system capabilities, guiding development and ensuring stakeholder involvement. However, challenges such as shortening development cycles for early and regular stakeholder feedback and managing an increased number of system tests were noted. Our study makes a significant contribution to the field of Intelligent Environments by providing a structured approach to embedding and managing quality throughout the development lifecycle. The multiple case study offers empirical evidence of the effectiveness of the proposed approaches, with ongoing considerations for challenges in the development process.