just for the sake of it:
In Germany, the transition altitude is determined by the current QNH. The requirement ist that the TA is 5000' agl, and the Transition Level at least 1000' above. For standard atmosphere it'd be FL60.
e.g.
If the current QNH ist 1000hPa this leads to a difference in actual altitude of approx. 390' (1hPa approx. 30'). If FL60 is kept as TL then the actual difference would only be 610', so the TL is raised to FL70 (giving us a spacing of 1610' between TA and TL). Vice versa, if the QNH were to read unlikely 1047hPa (equals 1020' ) the TL would be FL50.
always happy transitions...