This may be a simple post and many of you may already be aware of the following but I am going to post it anyway! When modelling in Revit you will have a tendency to start at Level 0 but will later receive the correct or revised levels and need to change the levels. There is a simple way of achieving this rather than trying to move the entire structure, you can simply change the elevation base to shared.
In the above image you can see that the base level is set to 0.00m. To change this to the new required level, click the Manage ribbon and choose Coordinates – Specify Coordinates at Point. Click the Level you want to specify and then you can enter the correct level.
Nothing will change until you change the type properties of the Level and any Spot Levels you have on the model. Select a level and then choose type properties. You will need to change the Elevation Base from Project to Shared. This will then update all the levels within your project. You will need to also do this for your spot levels.
Hope this helps,