I'm running 10 frame mediums, and installed 2 packages at the beginning of April ... they are brand new hives, no drawn foundation (small-cell plastic frames).
I did my weekly inspection today and found that most of the frames had been drawn out (and were being filled) in both hives ... save 3.5 (frames) in one hive and 4 in the other. So I'm guessing maybe around 60% drawn out in one hive and 65% in the other. The weather is really warming up this week and the bees are extremely active ... I decided to add an additional super (10 frame medium) on top ... I'm wondering if maybe I did it a bit early though. Should I have waited until they were more like 80% filled? I just didn't want them to all of a sudden scurry into major activity (we've got major blueberry bloom happening right now) and run out of room before my next inspection. Right call, wrong call? I'm a first year beek by the way.
I also took one frame of brood from each hive and moved it up to the new box, right in the middle (bait frame I guess I've seen it called) ... I'm now full of new beekeeper regrets as to whether I did this all too early!