Apparatus for providing a height reference for a tool of a construction machine, comprising: a laser transmitter arranged at a predetermined height over a ground to be processed by the tool of the construction machine; and a laser receiver arranged at the predetermined height and spaced apart from the laser transmitter along a distance to be processed by the tool of the construction machine, wherein the laser transmitter is configured to emit one or several laser beams (130, 144, 146) for the definition of a laser plane such that their longitudinal direction vector is directed to the laser receiver, wherein the one or the several laser beams (130, 144, 146) may be received by a receiver arranged at the tool of the construction machine in order to determine the height of the tool over the ground to be processed, wherein the laser transmitter and the laser receiver each include a laser transceiver (106, LTR) for transmitting and receiving laser beams (130, 144, 146), wherein the apparatus comprises a plurality of laser transceivers (106, LTR) spaced apart along the distance to be processed, and wherein the apparatus comprises a communication connection that connects the plurality of laser transceivers (106, LTR), characterized in that two neighboring laser transceivers (106, LTR) are configured to communicate with each other in order to cause an orientation of the longitudinal direction vector of the transmitting laser transceiver (106, LTR) to a reference position on the receiving laser transceiver (106, LTR), and the receiving laser transceiver (106, LTR) is configured to cause, in response to a communication with the transmitting laser transceiver (106, LTR), an inclination at least of a receiver part of the receiving laser transceiver (106, LTR) according to an inclination of the transversal direction vector of the laser plane generated by the transmitting laser transceiver (106, LTR). a laser transmitter arranged at a predetermined height over a ground to be processed by the tool of the construction machine; and a laser receiver arranged at the predetermined height and spaced apart from the laser transmitter along a distance to be processed by the tool of the construction machine, wherein the laser transmitter is configured to emit one or several laser beams (130, 144, 146) for the definition of a laser plane such that their longitudinal direction vector is directed to the laser receiver, wherein the one or the several laser beams (130, 144, 146) may be received by a receiver arranged at the tool of the construction machine in order to determine the height of the tool over the ground to be processed, wherein the laser transmitter and the laser receiver each include a laser transceiver (106, LTR) for transmitting and receiving laser beams (130, 144, 146), wherein the apparatus comprises a plurality of laser transceivers (106, LTR) spaced apart along the distance to be processed, and wherein the apparatus comprises a communication connection that connects the plurality of laser transceivers (106, LTR), characterized in that two neighboring laser transceivers (106, LTR) are configured to communicate with each other in order to cause an orientation of the longitudinal direction vector of the transmitting laser transceiver (106, LTR) to a reference position on the receiving laser transceiver (106, LTR), and the receiving laser transceiver (106, LTR) is configured to cause, in response to a communication with the transmitting laser transceiver (106, LTR), an inclination at least of a receiver part of the receiving laser transceiver (106, LTR) according to an inclination of the transversal direction vector of the laser plane generated by the transmitting laser transceiver (106, LTR).