Enclosing a washer & dryer is no different than doing a pantry detail or other cabinetry designs.

If you do this, be sure that you have sufficient room to get the appliances in and out of their spaces and also a bit of room available if these break and new ones are slightly different dimensions. My Sister-in-law had the problem that a new washing machine wouldn't fit into the existing space easily and ended up having to have the cabinet modified to get the new machine installed.

You will need deeper worktops on that run - as the appliance is a square box in effect - and so, for the kick space to look right - make that entire run deeper ( and either attach the plinth to the opening doors or have it easily removable for if you need to Move the WD )

I second the deeper worktops because you should leave the door of the washer just a crack open to avoid smells.