Prices for new homes under construction in the Greater Toronto Area (GTA) climbed to a new record high in September, after the benchmark soared over 30% year-over-year to $1.57 million.

September's price surge was fuelled by dwindling inventory, which failed to keep up with sales, according to the Building Industry and Land Development Association (BILD), which represents home builders.

In September, total new home sales reached 3,561, 16% above the 10-year average, while sales of new single-family homes -- including detached, linked, semi-detached houses, and townhouses -- accounted for 1,073 units sold -- a 3% dip below the 10-year average.

September also saw the third-highest number of condo sales, which includes units in low, medium, and high-rise buildings, stacked townhouses, and lofts, for the month with 2,488 units sold -- marking a 27% increase above the 10-year average.

READ: Toronto Condo Market Experiencing Resurgence as Demand Picks Up Steam

Unlike new single-family homes, inventory for condos increased in September compared to the previous month, to 11,107 units, due to several new condominium projects opening.

On the other hand, the remaining inventory for single-family homes, which includes units in pre-construction projects, in projects currently under construction, and in completed buildings, slipped to 1,322 as units that opened failed to keep up with sales.

“While available inventory is relatively low for both new single-family homes and new condominium apartments, the current supply dynamics are different for each sector," said Edward Jegg, Analytics Team Leader at Altus Analytics, Altus Group, BILD’s official source for new home market intelligence.

“There is very little new single-family product making it to the market, which is driving prices to new records. In contrast, there are significant levels of new condominium apartment product being launched, but strong demand means it is being bought up relatively quickly”.

With little new inventory hitting the market, the benchmark price for new single-family homes reached another record high of $1,573,764 in September, up 33.5% over the last 12 months. At the same time, the benchmark price for new condominium apartments eased in September compared to the previous month, to $1,036,831, which was up just 2% over the last 12 months.

“At a time when new housing supply is being rapidly absorbed by the market, it is more important than ever for municipalities across the GTA to remove every roadblock to bringing more housing online,” said Dave Wilkes, BILD President & CEO.

“Whether municipalities are considering affordable housing initiatives or implementing Growth Plan commitments that define where new growth will occur, they must retain a laser focus on bringing supply to the market as quickly as possible, as the region prepares to welcome four million more residents by 2051,” said BILD.

But even before 2051, it's expected that the province will welcome an anticipated 2.27 million more people over the next ten years. To keep up with the expected population growth, which includes new young families, and to address current and future housing supply shortages, Ontario will need at least one million new homes built by 2031.