I am not really certain what you mean. In general kicad has many options on how to assign footprints and all of them have a way to show a preview (which i assume is what you are looking for.)
More details see: How can i assign a footprint to a symbol?
In your screenshot you measure relative to what i assume is the courtyard outline. You do not measure against the body size of the component! (The body is smaller than the bounding box taken up by the pads for such devices.)
The courtyard area is already what should be used to ensure you have clearance between parts (The official footprints use IPC [industrial standard] nominal density rules here. These rules specify 0.25mm clearance to both pads and body.)
You can easily modify the footprints and increase it to whatever setting you like. (Especially for two terminal smd components like resistors. These are scripted. Courtyard clearance is a parameter that can be easily changed in the settings files: kicad-footprint-generator/scripts/SMD_chip_package_rlc-etc at master · pointhi/kicad-footprint-generator · GitHub)
Since version 5 courtyard is checked by the rule checker.