Looks good and tidy.
Aside to what has already been mentioned about the ceiling and walls. How about a series of black roller blinds mounted around the sides? You keep a nice light and airy environment but can drop the blinds during the actual shoot to stop unwanted reflections.
Just an idea i had for if i ever do the same to my garage.
good idea, i'd considered different colours for headshots, so a black would be just as easy!