An extruded hollow longitudinally elongated building element into which concrete is to be poured once combined with other like building elements to form a wall or a panel, the building element being extruded so as to be integrally formed and comprising: a pair of longitudinally extending spaced side walls which are generally longitudinally coextensive and longitudinally parallel; a plurality of longitudinally extending spaced transverse webs (16, 17, 18) joining the side walls, the transverse webs (16, 17, 18) including a first and a second end web; a pair of longitudinally extending grooves, each of the grooves being formed in a respective one of the side walls; a pair of longitudinally extending end flanges, each of the end flanges extending from a respective one of the side walls; a pair of longitudinal diverging surfaces that diverge from the first end web toward the grooves; and wherein the end flanges are positioned and configured to engage a respective one of the grooves of a like element, and the end flanges are resiliently deformable by engagement with the longitudinal diverging surfaces of the like element so that, when the end flanges are moved in a transverse direction relative to the longitudinal diverging surfaces of the like element, there is a resilient deformation of the end flanges to allow snap engagement of each end flange in a respective one of the grooves of the like element to thereby secure the building element and the like element together by snap engagement; wherein each end flange includes a first portion extending the respective side walls, and a second portion extending transversely from the first portion; and wherein the transverse webs (16, 17, 18) further include an intermediate transverse web spaced between the first and the second transverse web; characterized in that it comprises a sealing projection extending from each end flange and extending longitudinally thereof; and in that the sealing projection of each end flange extends transversely from a respective one of the end flanges toward the like element to aid in sealingly connecting the building element and the like element. a pair of longitudinally extending spaced side walls which are generally longitudinally coextensive and longitudinally parallel; a plurality of longitudinally extending spaced transverse webs (16, 17, 18) joining the side walls, the transverse webs (16, 17, 18) including a first and a second end web; a pair of longitudinally extending grooves, each of the grooves being formed in a respective one of the side walls; a pair of longitudinally extending end flanges, each of the end flanges extending from a respective one of the side walls; a pair of longitudinal diverging surfaces that diverge from the first end web toward the grooves; and wherein the end flanges are positioned and configured to engage a respective one of the grooves of a like element, and the end flanges are resiliently deformable by engagement with the longitudinal diverging surfaces of the like element so that, when the end flanges are moved in a transverse direction relative to the longitudinal diverging surfaces of the like element, there is a resilient deformation of the end flanges to allow snap engagement of each end flange in a respective one of the grooves of the like element to thereby secure the building element and the like element together by snap engagement; wherein each end flange includes a first portion extending the respective side walls, and a second portion extending transversely from the first portion; and wherein the transverse webs (16, 17, 18) further include an intermediate transverse web spaced between the first and the second transverse web; characterized in that it comprises a sealing projection extending from each end flange and extending longitudinally thereof; and in that the sealing projection of each end flange extends transversely from a respective one of the end flanges toward the like element to aid in sealingly connecting the building element and the like element.