Mass customization allows customers to configure the properties of products to their specific wants and needs. Customizations can be applied to any product, from clothing to furniture. The configurations are often performed in product configurators. One domain where the configuration of products is important is commercial interiors, where products, like furniture, need to be specified to fit the needs of the clients. Designers and salespeople in the commercial interior domain use configurators daily to perform their work tasks and therefore need configurators that are easy to use and adapted to their needs. This study investigates what needs commercial interior configurator users have on the interface to help them have a good user experience. First, some existing configurators are analyzed and interviews are held to understand what the requirements of such a system are. This information is used to create a persona to represent the users of the system. Requirements are elicited during this process which are used to prototype two interface designs. These designs are then evaluated using usability testing to ensure they fulfill the requirements and see if any additional requirements can be found. The results include a list of requirements and suggestions for how to design an interface that fulfills the requirements. The study showed that it is important for a commercial interior configurator to be detailed about which options are available, which have been selected, and how they affect the price. The navigation is also important to consider. It should be clear where one selection ends and another begins as well as how to find different selections. As there may be many different options available, it must also be easy to filter and find the options relevant to the particular configuration.