Home price growth is finally decelerating—and it’s just the start

But there’s a bit of good news for homebuyers. The latest reading of the S&P CoreLogic Case-Shiller Index, the leading measure of residential real estate prices, finds year-over-year U.S. home prices rose 19.5% between September 2020 and September 2021. That slight 0.3% dip marks the first price growth deceleration in nearly two years.

At first glance, that tiny dip hardly looks significant. However, a closer look at the numbers shows this deceleration is larger than the top-line figure would suggest. While home prices are up 19.5% year over year, most of that uptick occurred back during the red-hot stretch this spring and summer. Indeed, the month-over-month jump in September was just 1.18%, which is far below the pace prices would need to rise to maintain a 19.5% annual rate of return.

And this deceleration in home price increases is just getting started. At least that’s what industry insiders are telling Fortune. What’s going on? This fall the housing market began to slow down a bit as seasonality—a cooling period that happens most years around the holiday and vacation season—returned to the market after it was absent last year. Additionally, some would-be homebuyers finally started balking at sky-high prices. This has been happening for a few months, however, and lagging sales data means we had to wait a while to see that first price deceleration on paper.

While there’s a consensus in the real estate industry that price growth will continue to decelerate—the current growth rate simply isn’t sustainable long term—there is not a consensus of what the rate of U.S. home price growth will look like in 2022.

Among the seven industry forecast models that Fortune reviewed last week, Zillow’s model was the most bullish. The online listing site is predicting prices will rise another 13.6% between October 2021 and October 2022. While Zillow’s forecast would represent a 5.9 percentage point deceleration from the current top-line figure, it would hardly represent price relief. After all, even in this hot labor market, the average annual raise is still only 3%. Similarly, 12-month forecasts by Goldman Sachs (13.5% on an annualized basis), Fannie Mae (7.9%), and Freddie Mac (7%) all foresee home price growth remaining fairly strong next year.

But not everyone thinks price growth will remain evaluated above historical levels of price appreciation (up on average 4.6% since 1980). Look no further than Redfin, which is predicting price growth will fall to 3%. Meanwhile, CoreLogic foresees price growth slowing to 1.9%, and the Mortgage Bankers Association forecast the median price of existing homes will actually decrease by 2.5%.

If the economic models produced by the Mortgage Bankers Association, CoreLogic, or Redfin come to fruition, it would give buyers some breathing room, right? That would be true on the price front; however, the overall cost could be the same.

The reason these three models are more bearish on prices is because they believe that mortgage rates will rise fairly quickly next year. Redfin predicts the current 30-year average fixed mortgage rate will climb from 3.1% to 3.6% by the end of 2022, while the Mortgage Bankers Association forecasts 4%. At that increased mortgage rate, the price savings (that is, not growing by the 13.6% rate predicted by Zillow) would essentially get wiped out by added interest to the loan.