You can create a Dynamic Component that will allow you to edit overall height and width separately, AND also separately change the stile and rail widths and thicknesses, and even the number of stiles and rails.
Here’s an example set up to draw softwood frames, without any door panel, to give you something to start from. It’s saved back to v2017, so you should be able to open it in v2020. I created it a few years ago.
R-click on the component and choose Dynamic Components/Component Options to change its size. It should work in either Feet and inches, or metric, depending on your Model Info/Units settings, but its preset sizes are set in inches.
Frame DC.skp (70.6 KB)
R-click and choose Dynamic Components/Component Attributes to see how to edit the way it works.
Look on the Sketchup YouTube channel for guidance on developing your own DCs, and in particular for one that shows how to create a frame or door with rails and stiles.
It is set up to use softwood, chosen by nominal dimensions, for UK softwood. That allows 1/8" or 3mm planing allowance for nominal dimensions up to an inch, and 1/4" or 6mm for larger dimensions. US and Canadian softwood has larger planing allowances - 1/4" and 1/2" respectively.
If you are working in hardwood, and want to be able to specify finished sizes, you’d need to change the input options to accept lengths instead of a dropdown list of nominal sizes.
Here’s another example from the 3D Warehouse, which has a raised panel, in which rails and stiles are the same width, and you have a choice of shapes of the panel.
IMPORT this model, DON’T OPEN it, to get the DC options when you R-click on the selected component.
Dynamic Cupboard Door.skp (341.1 KB)