Many software systems, particularly those in safety-critical domains or managing personal data and financial transactions, must comply with domain-specific laws and regulations, while also balancing societal values. Prior research has focused on either regulatory compliance or human values, but not their integration. This paper proposes the Accountable Design Assistant (ADA), which identifies relevant laws, connects them to societal values, and evaluates candidate design solutions from both legal and values-based perspectives. We demonstrate ADA’s ecological validity through two case studies: a Wireless Baby Monitor and three multi-vehicle autonomous Unmanned Aerial Systems. Additionally, a focus group of domain experts reviewed the outcomes, providing initial validation of the approach. These results suggest that ADA’s dual focus on laws and values effectively supports the design of legally compliant systems.