US homebuilders' confidence slipped again this month, bogged down by persistent worries over affordability and high construction costs. 

An index of market conditions from the National Association of Home Builders and Wells Fargo edged down in February to 36, the lowest level since September. That fell short of all but one estimate in a Bloomberg survey of economists. A value below 50 means more builders see conditions as poor than good.

"While the majority of builders continue to deploy buyer incentives, including price cuts, many prospective buyers remain on the sidelines," NAHB Chairman Buddy Hughes, a North Carolina builder, said in a statement. "Although demand for new construction has weakened, remodeling demand has remained solid given a lack of household mobility."

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Affordability remains a challenge for millions of would-be homebuyers and continues to restrain the housing market. While mortgage rates are near the lowest in more than a year, they're still double the level that prevailed throughout much of 2021. Builders have had to respond by cutting prices and offering incentives, such as making upfront payments to lower customers' mortgage rates. 

This month, a still-elevated 65% of builders reported using sales incentives, unchanged from a month ago. Meantime, the share of builders who reported cutting prices fell to 36% in February, the lowest since May, NAHB said.

The use of incentives, as well as lower mortgage rates, should help home sales rebound this year. Meantime, the Trump administration's efforts to address affordability remain "a wild card," Bloomberg Intelligence analyst Drew Reading said in a January note.

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Among the components of NAHB's index, an index of sales expectations in the next six months fell to 46, remaining below the breakeven level of 50 for a second straight month. The gauges of present sales and prospective buyer traffic have each been below that threshold for at least a year.

Around the country, builder sentiment fell in all regions but the South, the nation's biggest homebuilding region.

On Wednesday, the government will release its new residential construction report for November and December, which were delayed by last year's record-long government shutdown.