Practice KYBO. Keeping Your Broodnest Open. Put alternating 'empty' frames between those frames already drawn and with brood. The only exclusion; don't put brood frames on the outside ends (even in your part of the world brood can get chilled). In other words, going from front to back (or visa versa) you should have an empty frame or two then one brood frame, followed by an empty, then a brood frame, then an empty, and so on until you go through all frames. Keeping brood nest open will also assist with limiting swarms by giving bees something else to do. Good Luck.