The housing data was great yesterday. The drop was caused by a quirk in multi-family starts in New York (building code change).
Finished houses are meaningless - in fact, the lower the better. The fewer houses on the market right now, the fewer to sell until demand catches up, sucks up all the inventory and gives builders pricing power again.
If you wan ta clue as to when things are going to turn around, watch mortgage applications, and mortgage rates - especially the spread between rates and the applicable treasury rate. As that spread drops, it means banks are getting more capable / willing to lend.
When the lenders come back, then the bottom will definitely be passed.