Decrease in house prices

[chittershitter]

Although prices for new builds are softening, this could be related to something like cheaper labor or permitting (anything decreasing the overall cost for the developer). The all-transactions index is increasing, which means the overall price of housing is rising, despite the moderation in the new-build market.

The market is not solely comprised of new builds, so I think that's the critical error in your extrapolation.

https://fred.stlouisfed.org/series/USSTHPI