4-7 on the grand canyon scale.  III- to IV+ on the international scale.  This rapid becomes harder at lower water.  The river pushes towards the left wall across a sandbar at the top of the rapid.  This creates a series of wave trains running down the left wall.  Problem is there is a very large hole at the bottom left of the rapid.  Enter at the left of the rapid by the wall and pull right to miss the hole.  If you pull to soon you will hit the shallow sand bar area on river right.

Rock house rapid hole will easy flip any raft.  This is considered one of the harder rapids on Marble Canyon

Scout from the sand bar on river right.  Flash floods are changing House Rock rapid and other rapids in Marble Canyon so unless you run the canyon regularly, it's probably a great idea to scout.