Walking up stairs a good idea?

Seems like ANY added exercise would be good but make sure that you include this in your log so you compensate with extra calories! Climbing 7 flights is intense and you would need a bit of extra energy. Also, if you're wearing inappropriate shoes or carrying a heavy load on your back, this might NOT be the best idea for your health! If your load is light and your feet properly shod, you are probably doing a good thing! You could always ride the elevator up, drop your books and change shoes, and then go back down for another trip the old fashioned way! Don't hurt yourself, and eat a bit more to cover your expenditure!

Of course it's good for you! If you have the energy at the end of your school day to climb up seven flights of stairs, do it! Whether it will be enough to keep the weight off, you'll have to wait and see. Remember that a big component of weight management is food choices. Probably with a combination of healthy food choices, walking a couple miles each day, and climbing the stairs a couple times a day you'll be able to manage your weight. If not, if you see that your clothes are getting too tight, add something else into it.

You might want to include some upper body strength work to balance things out, though. The walking, hills, and stairs will probably be plenty for your legs, but your arms aren't getting much with this. Maybe do so upper body work a couple times a week?

Any extra walking and stair taking is going to benefit you. I often park farther away than necessary and take the stairs to add to my daily activity. However, the most effective activities for burning calories are those that get your heart rate up, so if you can...try really getting into it with some speed when you climb those 7 flights! Lots of people experiencing success never hit the gym, the world is our gym! You can always go up and down a few times in a row if you want to get in a longer more intense workout.

Any movement is worth it. The more active you are the higher the number of calories your body will use to just sustain normal activity. I am very active during my days and thus when I determined my calorie goals I accounted for that. I need more calories each day because I am active.

I would absolutely count the stairs etc as exercise, that is until that day when you make it up the stairs without being winded or you find yourself running up the stairs and down without giving it any thought...at that time, change you activity setting in MFP to account for being a lightly active person.