Ohnap
At the risk of sounding pushy, I think we need to revamp the group. Are you open to new ideas?
here are my two biggest suggestions - 1) we make the house assignment by choice (or by some kind of draft) not by birth date
2) We make the groups open for everyone to visit and post on them
Here are some of my other suggestions:
more spam
Another big one would be limit the number of houses to 3-4 at first, then when (if the grousp get up to 8 memebers, start a new house.
More games and inter house challenges (I can come up with some ideas if you want)
A discussion with links to the house groups so newcomers can go to them quickly. It should have the links and rules on joining house in the OP