A custom storage assembly design module automates design of a storage assembly by automatically generating a recommended layout based on a user defined storage location. The design module, which can be communicatively coupled to a remote communications device including a monitor, provides custom design options in view of the recommended layout for the storage assembly, and monitors the selection of custom design options to avoid violation of allowance rules for the defined storage location. The design module displays the storage assembly with currently selected custom design options and also associated pricing information throughout the design process.