US construction spending hit a seven-year high in September after a modest rise in the previous month, the Commerce Department has reported.

Despite some signs of slowdown elsewhere in the economy in the month, September spending on building new homes, highways, offices and other facilities held up at an annual pace of $US1.09 trillion ($A1.53 trillion), just 0.6 per cent better than August but 14.1 per cent higher than a year before.

The last time spending in the key economic sector was that high was in March 2008 as the country was plunging into the economic crisis.

Both private sector and public sector construction spending continued to grow, with outlays in the larger private sector 16.0 per cent above a year ago and public construction spending 9.4 per cent higher.

The fresh data suggested that the housing sector specifically remains healthy despite some recent data suggesting a slowdown. Private spending on housing construction, the largest component of all construction spending, picked up 1.8 per cent in the month and gained 17.2 per cent year on year.

Eventually that could turn into higher supplies of new homes, to ease the current tight market that has pushed prices high enough to deter buyers, according to industry specialists.