The invention relates to a device, system and method for measuring moisture in building structures. A tubular body part (100) may be embedded in a material during its casting. Hole(s) (106) provided in the body part (100) lets moisture inside a space separated by the body part (100). Measuring element including electronics (102) and a sensor (104) functionally connected to the body part (100) is used to measure the separated space 108. With a reading device (234), the results may then be read from above surface due to a provided wireless link between the measuring element (102) and (104) and the reading device (234).