This paper focuses on the objective study of emotions, namely, fear induced by architectural spaces, by sensing and statistically analysing some physiological signals of users experiencing Virtual Environments (VE). For this, a virtual building was designed considering the presence of stairs and ramps as architectural elements that could affect users´ physiological states and perception of fear of falling. Thirty-one older persons participated in this study and were assigned to two experimental conditions (i.e., safe and unsafe conditions). Five main locations (beginning of the stairs; neutral room; first descending ramp; ascending ramp; and the middle of ascending ramp) were considered along the participants' path, and heart rate (HR) was collected in the vicinity of those locations. Results shown significant differences in HR activation among neutral, beginning of stairs and middle of ascending ramp. Despite the fact that the effect of condition was not fully verified for HR, participants reported more fear while interacting with the unsafe condition, with significant differences between conditions.