Terrestrial Laser Scanner technology has developining on mapping sector now. With high speed recording data, high accurate, and economical it was offered the advantage. One of terrestrial laser scanner utilization is for monitoring deformation shape of building. Usage the as built drawing data monitoring of deformation shape can detected. With inspecting past shape building and existing shape building condition. This research was using FARO Laser Scanner Focus 3D with dimension 24x20x10 cm and weight only 5 kg. This instrument has horizontals angle measurement in the around of 305o and 360 o at the vertical angle. At this research scanning process has been done toward one of Tirta Moedal Semarang City Water Company asset, the klarifier water tank has been managed by production division of Tirta Moedal Semarang City Water Company. Collecting research data has been scanning almost 23 times towards both of the tank wich has been coded IPA III and IPA IV. Then after scanning data was obtained, and processed by Scene 5.2 software. And then based on as built drawing design was obtained from Tirta Moedal Semarang City Water Company can do comparison processed related building deformation study. Deformation of building shapes have occurred on klarifier tank and detected on klarifier tank of Tirta Moedal Semarang City Water Company. Building deformation has detected high about 0,062 m longer than as built drawing and has diameter about 0,092 m longer than the as built drawing design of IPA III unit. At IPA IV tank unit has different high 0,025 m shorter than the as built drawing, and about 0,003 m longer than as built drawing of IPA IV unit. And at the other IPA IV tank has height about 0,054 m and diameter about 0,022 m shorter than the as built drawing design.