Until recently, built environments have been designed exclusively to meet the needs of neurotypical populations; however, there is increasing recognition of the need to make built environments more accommodating for neurodiverse populations, including autistic individuals. This scoping review aims to comprehensively explore and synthesise this literature on the internal built environment for autistic individuals providing recommendations for designers, policymakers and clinicians. Five electronic databases were searched, resulting in a total of 28 studies being reviewed. Recommendations are provided for design and construction, lighting, sound, aesthetics, temperature and air quality. While in its early stages, evidence demonstrating the impact that particular qualities of light, colour, sound and spatial planning have on the human sensorium is emerging. In turn, this new knowledge is informing design decisions that are progressing interior environments towards inclusivity. Understanding the positive and negative impacts of decisions made in the design of the built environment has the potential to facilitate the participation and inclusion of autistic individuals.