Also that's a lot of time spent making meals. I doubt he's including researching recipes, shopping & cleaning up for 3 meals a day in his 1 hr/day estimate.
Also note with this particular arrangement the commuting time is significantly reduced.
If living together is sufficient to create enough stress that the group can no longer function, you were never going to make it anyway.
As for the time preparing the meal (from researching recipes to cleaning up), I'd say it can take less than 1.5 hrs per day total. Imagine buying in bulk, cooking a large, delicious stew that can last a couple days (just warm up the meals in a microwave), and voila. Time and money saved.