A building element (1) is disclosed which is formed with the same dimensions or appearance as a standard building element. The building element (1) comprises at least one inlet opening (4) and at least one outlet opening (5) and a means for guiding a fluid from the inlet opening (4) to the outlet opening (5) along an inner surface of a heat transfer area (2) and thereby enabling the transfer of heat between the heat transfer area (2) and the fluid. The building element (1) enables the replacement of traditional building elements by elements which can be used for heating or cooling of specific building surfaces, thus permitting, or enhancing, heat transfer arrangements within a building.