WHY LINK FILES
The reasons a project may be split into separate linked files include:
to isolate work
To isolate continually changing portions, such as facades.
To isolate complex portions, such as facades.
To isolate areas of project team responsibility.
to isolate the work of others
Typically consultant work.
Also portions that will become consultant work, such as structure.
to isolate rarely used portions
For example portions that are only needed for intermittant reference.
to isolate fixed, or rarely changed portions
Portions that must not be changed.
to isolate troublesome imports
For example imported CAD files, or portions built by others.
to reduce file graphic complexity
The amount of information you see on your screen effects performance.
Separating out and not loading portions can reduce complexity of what you are viewing.
to reduce file computation complexity
Revit by nature maintains connections between parts, that need to be recalculated whenever changes are made.
Sometimes these connections are unnecessary and can be broken by seperating portions into seperate files.
to reduce file size
A large file can increases the amount of time it takes the file to load.
A large file also uses a lot of RAM memory.
But:
Load time and memory use is only reduced if links are not loaded.
Saving is not effected as only changes are saved.
Reducing the file size does NOT necessarily reduce graphic complexity or computational complexity.
LINKED FILE RECOMMENDATIONS
The actual files that are linked will largely be project dependent.
Below are descriptions of the type of things that should be considered when deciding which files to link.
SURVEY PLAN
Survey CAD plans often have a far distant base point, which can cause problems in Revit.
By putting it in its own Revit file and linking it these problems are overcome.
The linked file containing the survey plan might also include other fixed existing items like context and/or site.
CONTEXT INFORMATION
Surrounding buildings, streets, etc that won't be changed.
SITE INFORMATION
Toposurfaces, landscaping etc that is only required at ground level.
CAD FILES
If there is a set of CAD files you need to link (e.g. a set of floor plans), place them in a separate linked Revit file rather than directly linking them.
CAD files can bloat a Revit file and add a lot of useless linetypes, line patterns, fill patterns etc.
If you have multiple floors plans place them on corresponding levels in the linked Revit file.
EXPLODED CAD FILES
If you have to explode an imported CAD file to make changes do it in a separate linked Revit file or family file.
Alternatively make changes in the CAD file and link it rather than import it.
Exploded CAD files can cause file bloat and problems in Revit.
CONSULTANT MODELS
Revit files provided by others must always be linked.
STRUCTURE
Structural consultants file will be a link, but consider making structural elements by us also a linked file.
CORES
If cores are complex, otherwise include in structure.
FACADE
External facade. Carefully consider where the facade starts and finishes.
Develop a method that ensures rooms are still enclosed when the facade is unloaded.
FF & E
Consider putting Furniture and Specialist Equipment in a seperate linked file to the construction model.
Built-in Specialist Equipment may be kept in the construction model, but only if it is really really built in.
View, Details, Schedules and Sheets for FF&E also live in the FF&E model.
Furniture and Specialist Equipment components are quite complex and add a considerable load to the base model.
See here for a comparison on a real job.
AREA PLANS
Whenever a change is made to the model area plans recalculate their areas.
If you have a lot of area plans in your file this can slow performance.
Link other Revit files into an Area Plan file and do area plans there.
Recalculations will then only occur when you open this file.