This is a very vague question but it isn't cheap. Even the smallest college renovating their smallest cafeteria will be costly. As an estimate for a 200 person capacity cafeteria, renovating not only the front of the house (the tables, serving stations, building, etc.) but also the back of the house and kitchen, your looking at least $1.5-$2 million.
Looking at bigger schools, there's a lot more to consider. Not only does the size matter, but also everything else associated with a larger university. Considering a 750 person capacity cafeteria, the cost would range from $3-$6 million.
Chat with our AI personalities