Due to a high competitive pressure on the global software market, in many areas the software industry is moving from hand crafting to semi-automatic or automatic software construction based on Software Product Lines (SPL). Techniques to automate the construction of software products from SPLs are widely available. These can handle variability in source code artifacts but they are inappropriate to handle variability in Graphical User Interfaces (GUIs). The main reason is that they are not designed to handle such fine grained configurations as they are required to configure GUI frameworks or toolkits. To nevertheless employ them in GUI generation tasks is complex and time consuming. However, in the Human Computer Interaction (HCI) community approaches to develop GUIs in a model-based manner and with constraint-based techniques are worked on that help automate the construction of GUIs. Therefore, the main hypothesis of the proposed research is that constraint-based GUIs techniques are a well suited basis for reducing the customization effort of generated GUIs of SPLs. The paper proposes a research plan to employ these new HCI techniques in generating GUIs for SPLs.