Building code knowledge is essential for designers, but it can be challenging to learn and master. While automated code compliance tools assist in navigating these complexities, they are typically used later in the design process. This study introduces the Building Code Calculator App as an early-stage design tool. Grounded in cognitive load theory, the app simplifies information to simplify the learning process. It also incorporates concept mapping, a visual tool that aids in knowledge construction. This research aimed to examine the effectiveness of the Building Code Calculator App as a tool for design education. The app offers a visual guide to building codes and includes calculation features with explanations. It was hypothesized that the app would improve designers’ knowledge and skills while reducing their stress levels as they work on building code tasks. The study also predicts that the app will be adopted by designers in the future. A survey was conducted with senior interior design students after they completed a building code task using traditional methods and then used the app. All of the survey participants indicated the usefulness of the Building Code Calculator App in assisting the application of building code’s content and expressed disposition to use the app in the future. Results also confirmed that using the app lowered the participants’ stress levels, demonstrating its value as a design tool. In conclusion, these results advocate for a more comprehensive approach to building code education that leverages technology to provide practical, hands-on learning opportunities.