You can very easily choose to plan your build in either Cm or Inches in two different ways 


1) Using the Options Menu 


By going to SETTINGS and choosing OPTIONS in the vanspace Toolbar

Full Functions walkthrough v2.08


Leaving the Tick in USE METRIC MEASUREMENTS will give you CM 

Removing the tick in USE METRIC MEASUREMENTS will give you Inches

Once you have made your selection, click CLOSE and RETURN TO VAN 



2) When you have placed your item in your van layout click on the object so that the Gizmo appears and the measurement box on the left hand side

You can then simply click in the bottom field to toggle between CM or Inches