Be practical by the pavement by thinking about snow plowing, snow piling, over hanging bumpers, and stupid people (how they park, where they walk). Think safety - make sure people can see pedestrians and other cars as they back out of parking spaces or drive in the lot. Herbacious perennials and ornamental grasses are good where woody shrubs may get broken by snow or an idiot who goes over a curb because they come back the next year without losing shape.
Keep in mind that it is not a residence where the garden is respected - it is a place where chumps will use a tree as a bike rack and the shrubs as a place to toss their trash. Make sure it is easy to clean (ie, not barberry or rugosa roses).
Remind yourself that the first responders for maintenance are most likely going to be bus boys and prep cooks - there will be half a barrel of salt dumped on an inch of snow because they don't want to shovel it and anytime a weather situation or other need makes them have to move outdoor tables out of the way, they won't think twice about pushing them into your plantings.
Also, if smoking is not allowed in restaurants down there (like here) there will be lots of butts dropped by the entrance and back door to the kitchen. Makes sure the area can easily be swept and stone the nearby beds rather than mulch because of fire hazard (I have seen this happen).
Also, if it is a flat foof building, realize that in big storm events they will have the bus boys dump snow off of the roof, too.