Sketchup as been a software used by architectural firms for a long time because of its ease of use. Also Sketchup has a enormous library of free 3d models called 3dwarehouse.
This are the two reasons why we need to bring Sketchup files into Blender. Sometimes we receive the building model in skp from the client and we need to continue working on it or we want to use something fast from the 3dwarehouse.
If you have Sketchup i found that exporting as obj works great with Blender. But since the last versions of Sketchup are paid and some people don't have how do you do it?
I found a software that it's very handy when it comes to file conversions and it's free.
It's BricsCAD Shape. It's the little brother of the BricsCAD software family.
You can download it here:
The BrisCAD software includes CAD and BIM but for early stage concepts they have BrisCAD Shape.
With a very similar interface to Sketchup, it wants to be it's competitor in the Architectural Design field.
The main advantage for us it's is ability to import SKP files from any version.
And export them as FBX.
Then just import into Blender. The materials get lost but all the geometry is imported and we can easily make our materials in Blender.
This software is great to convert various formats into files that Blender can read.
BricsCAD Shape can open: DWG, DXF, and DWT
BricsCAD Shape can import: SKP
BricsCAD Shape can export: FBX (Binary and ASCII), BMP, STL, and DAE
Go try it out!