There are now 20 brand new homes for sale in HPP.

[Punatang]

One of the biggest U.S. lenders is offering 0%-down-payment mortgages for first-time home buyers. Here's the catch.

I dunno. 15k at no interest is 15k at no interest. As long as you understand the terms, it seems like a great deal. Personally, I would never pay it back until I had to. 

The "catch" is that you have to pay the money back eventually. Not that hard to understand.

The "catch" is a bit deeper than that.  You get the 15k at the peak of the market and at peak interest rates on your primary loan. You are now very stuck for a long time. You can't refinance when rates drop because you don't have the 15k to pay back.  So even if rates drop tomorrow back down to 3%, you are stuck at 7%. Insidious but very convenient for the purchasers of your bundled loan who will have a greater chance of  reaping above market yields until you are no longer able to pay, at which time you get sheared.
and
You can't sell in the near future because you don't have the 15k to pay back until prices have risen substantially.
and
If by a miracle you make your 360th payment, you now have a $15,000 balloon payment due immediately.

You may be sophisticated enough to make this work for you. Many are. Many are not. They will suffer. These mortgages are explicitly for people who make 80% or less of an area’s median income.
 These borrowers, by definition have no down payment, no savings, and many are already likely on the margins and one economic ripple away from missing payments. The economy is already faltering.

No doubt more of these schemes will roll out as we sputter towards the balloons inevitable pop.

Other than the late stages of the 2008 housing bubble, at least from where I'm standing, there has been no worse time in my lifetime to offer zero down mortgages.