It's not completely necessary to boil lasagna noodles before. Sometimes I do but when I'm feeling lazy, I don't. If you don't boil them beforehand, you will need more moisture, otherwise the lasagna will come out dry. If you choose to not boil the noodles, make sure to use two jars of pasta sauce for some extra moisture. The no boil noodles soak up a lot of moisture. Sometimes I add in 1/2 cup of water too.