Houston was an anomaly in the wake of the financial crisis, as the city’s surging economy kept the housing market strong. However, according to Zillow that may no longer be the case.

“Houston is starting to become not as affordable for first-time and low-income homebuyers,” Zillow’s Chief Economist Svenja Gudell said in an interview with the Houston Business Journal. “Teachers, construction workers and food service workers are finding it much harder now to buy a house.”

On paper, buying in Houston seems reasonable.

In an analysis released earlier this year, researchers from Zillow revealed that in Houston, buying a home is a more affordable option than renting. While homeowners in the city devote 11.9 percent of monthly incomes to mortgages, renters spend 30.33 percent of their incomes, making their payments 2.55 times that of the average mortgage payment.

The reality, however, is that inventory in Houston is low – now a 3.5-months supply compared to the nation’s 4.8 months. And while overall levels are inching up, building has stalled in the lower end of the market.

“Houston has a lot of inventory on the high end and is very low on the starter or entry-level homes,” Gudell said.

Millennials and first-time homebuyers are finding it hard to purchase homes in the Bayou City, not because mortgage payment are so taxing, but because rents are too high to save adequate down payments. And with home prices rising as rapidly as they are and are expecting to continue, the trend is unlikely to soon end.

Some experts believe the plummeting value of crude will eventually temper home price appreciation, but thus far, it has not been the case, and continued strength in the city’s other hallmark industries, such as healthcare, make a significant slowdown seem unlikely before, at least, 2016.