It's raining indoors????? Has anyone else had this problem and solved it?
This will only happen if you are using an exterior house mod. An exterior house is one where the "interior" is actually part of the exterior world. This means you can see out of and in through the windows, hear the birds chirping and the wind blowing through the trees while "inside". It also means that you risk raining inside unless the modder has done something to prevent it. My http://www.tesnexus.com/downloads/file.php?id=9169 and http://www.tesnexus.com/downloads/file.php?id=22846 use scripts to prevent it raining inside. Some others, such as Princess Stomper's http://princessstomper.wordpress.com/2009/06/08/princess-anvil-seaside-cabin-version-2-0/, use my no rain scripts with permission. Some others, such as Exilehunter's http://www.tesnexus.com/downloads/file.php?id=17229, are in their own worldspace where it never rains.
As SomeWelshGuy said, it would be helpful if you post what house mod you are using