A theodolite or total station is set up over a control point which has known co-ordinates.

The instrument is then pointed at another control point in order to orientate the instrument to north. If a conventional theodolite is being used it normal to turn the instrument to north and reset the horizontal angle to zero.

The distances and bearings from that control point to those points which require setting out are now located and fixed with pegs.

A control point which is located near to the structure to be set out will ensure maximum accuracy.

If a total station is used the co-ordinates are entered into the software and the prism target will allow the bearing and distance to be located for each point.

If a conventional theodolite is used the co-ordinates of the control point are compared with those of each point to be set out. This will require whole circle bearings and distances to be calculated for each point.

The procedure is then to simply turn to the required bearing and measure the distance ensuring that the tape is held as near horizontal as possible

Setting out and alignment in steel framed buildings