Construction managers periodically take photographs of on-site resources such as materials and facilities to document various aspects of construction activities. Although digital images can be effectively used for monitoring construction activities, they are not used at all but to show the situation of the site by being attached on the report. In this regard, this study proposes a system and a smart helmet that help site managers identify changes in the conditions of facilities and materials. The smart helmet is equipped with a small camera to record videos around the site, and a small GPS to collect the position data of the site manager wearing the smart helmet. The system includes two separate frameworks—one for fixed resources and the other for mobile resources. The system automatically detects changes in appearance of fixed resources and in locations of mobile resources. The frameworks involve image matching methods which play critical roles in detecting appearance changes of fixed resources as well as cross-checking the identities of mobile resources. Experimental results signify the system’s potential uses for effectively monitoring the conditions of on-site facilities and materials.