Revit differs from CAD in the way it manages common insertion points.
Whereas in CAD you rely on all files having the same origin, Revit has a method using Shared Coordinates.
In Revit you decide which file is going to provide the basis for all the other files (usually a site model, or the main central file),
then you either publish shared coordinates to other linked files, or aquire them from a linked file.
You only need to do this once for each file.
WHEN TO USE THIS METHOD:
Use this method when first setting a project up, and if you have a survey.
DO NOT USE THIS METHOD IF YOU HAVE CREATED ANY ELEVATIONS OR SECTIONS.
If your project has already started you will need to use the method described in
SET PROJECT BASE POINT by ROTATING TRUE NORTH.
Note that this method requires the file that describes the base point to be in a separate linked file to the main central file.
BEFORE OPENING REVIT
Important decisions that will have ramifications for the rest of the project life must be made before setting your Revit model up.
These decisions should be discussed with the project architect.
Changing these decisions once the project starts causes an enormous amount of confusion and work for the whole design team, so it is important to get it right.
1. Select where the shared coordinate base point is.
This will be used to cordinate all linked Revit & CAD files by the whole consultant team.
Ideally it should be a physical point identifiable on site (corner of a building), or corner of a title boundary.
2. Decide which building face or boundary will align with the top of sheets (and your computer screen).
Pick something that will ensure most of the building can be created orthagonally. Also consider how the project will fit on sheets.
3. Prepare the first Survey CAD file.
Open the survey CAD file. There is not a lot of point spending too much time cleaning it up, particularly if you expect future updates.
But you need to make sure there are features that clearly identify items 1 & 2 above.
For the base point the end point of a line is best. Make sure there are no other lines very close, or on top of, this line.
If necessary draw your own line in the CAD file.
It is prudent, but not necessary, to note down (or write in the CAD file) what the coordinates are of this point (use the AutoCAD ID command).
For aligning project north make sure there is a single line (not a polyline) drawn in the right direction.
Check for other lines very close, or on top of, this line. Work out how you will identify this line in Revit,
or if necessary draw your own line in the CAD file.
Take note of the units in the CAD file (usually metres). Double check by measuring something, sometime surveys are draw at a scale.
You need to know this when you link it into your Revit project.
Once this CAD file has been placed in your Revit project and the coordinate system has been set up you won't need to do this again if you receive updated survey files.
REVIT PROCESS
Start a new project file.
Go to the .datum Floor Plan view. If it doesn't exist create a new level at 0.000, name it .datum.
In view .datum set view parameter Orientation to Project North.
If not visible turn on Survey Point via Visibility/Graphic Overides > Model Categories>Site.
LINK CAD SURVEY
Link in the CAD survey Automatic Origin to Origin, setting Import Units to match units in the CAD file.
If the origin is more than 20 miles (32 km) away Revit will force it to link at Center to Center.
You will receive a warning, accept it.
SET BASE POINT
Select the Survey Point icon (blue triangle) and move it to your shared coordinate base point on the CAD survey.
Zoom in close to make sure it is actually where it is supposed to be.
ROTATE PROJECT NORTH
Identify which building face or boundary will be project north (see item 2 in BEFORE OPENING REVIT above).
Hint: use Visibility/Graphic Overides > Imported Categories to hide unnecessary layers.
From menu: Manage > Position > Rotate Project North.
Select Align selected line or plane and then pick the building face or boundary you want aligned with Project North.
If the orientation is not correct repeat the Rotate Project North command and select 90° Clockwise or 90° Anti-clockwise.
Use Rotate command to rotate the CAD file so that it matches Project North.
Test by change view parameter Orientation to True North.
Save your file. Name it so it is identifiable as the survey.
CENTRAL FILE
Open or create your main central file.
Go to the .datum Floor Plan view. If it doesn't exist create a new level at 0.000, name it .datum.
In view .datum set view parameter Orientation to Project North.
Link in the Revit survey file created above using Automatic Center to Center.
If you don't see anything try changing Visibility/Graphics of linked file to custom, and set to by linked view,
or make sure the view clip plane is above the highest level in the site model.
Select Coordinates > Acquire Coordinates from menu and pick the linked Survey file.
Test it has worked by changing view parameter Orientation to a different value.
Save your file and save to central.
ADD LINKED FILES
Link in the next Revit file at Center to Center.
Move and Rotate it to its correct location. Check height as well as plan location.
Select Coordinates > Publish Coordinates from menu and pick the linked file.
Save your central file, you will be asked if you want to also save the linked file, say yes.
Repeat for other linked Revit and CAD files.
Once files have shared coordinates you can link them using Auto - By Shared Coordinates rather than going through the publish/acquire procedure.
Consultants use the same process, so will aquire your shared coordinates from the file you give them.
This means when you receive their file it will come in at the correct spot if you use Auto - By Shared Coordinates.
A more comprehensive description is contained in this document by Franz Hein:
REVIC2010-04-13_Location-Location-Location.pdf
Franz recommends matching Revit coordinates to the survey CAD file coordinates.
If you do this it means when you use a Spot Coordinate in your model it will report the actual survey coordinate.
I don't know how useful this is. If you think it would be useful in your project by all means do it.
An explanation of the differences between Project Base Point and Survey Point:
Project Base Point And Survey Point Explained.pdf