The use of immersive virtual reality technology (IVR) has the potential to transform traditional educational practices. Within initial teacher education programs, IVR presents many opportunities as simulated classrooms can afford an accessible space for assisting pre-service teachers (PSTs) with learning and practicing the knowledge and skills required in the profession. The aim of this research is to demonstrate a proof-of-concept of an IVR classroom that intends to assist pre-service teachers with learning school-wide positive behaviour interventions and supports (SWPBIS) strategies for supporting low-level challenging behaviours. This involves the design and development of an IVR classroom environment, ClasSimVR. This informs the creation of a framework for designing interactive IVR environments (the DIIVR) for learning SWPBIS strategies. A research-through-design methodology underpins this research; with a proof-of-concept method being used to develop ClasSimVR. An expert review was conducted via survey by five positive behaviour interventions and supports or SWPBIS academics to inform the development of the proof-of-concept. ClasSimVR a serious game and an exploratory platform targeted at helping PSTs learn SWPBIS strategies; they learn and practice the use of nine SWPBIS strategies focused on supporting low-level challenging behaviours. This could represent the first use of an IVR serious game for this purpose. The DIIVR framework positions designing IVR environments for learning about SWPBIS within initial teacher education programs as having six key areas of consideration: context, immersion and presence, experiential, interactive, engaging and empowering. It introduces 46 fine-grained design principles which could be used to guide the development of future IVR environments for learning SWPBIS strategies. This research contributes to the discourse surrounding the design, development and implementation of both IVR environments and serious games for learning SWPBIS strategies within initial teacher education programs.