Producers of Channel Nine’s hit reality show The Block have taken on too much this current season, according to the show’s host Scott Cam.

This series challenges couples to renovate a three-storey 1980s office block in the upmarket Melbourne suburb of Prahran, turning them into five split-level apartments.

“Our contestants certainly struggle in the first four to five weeks and we’ve seen an unprecedented number of rooms just not finished in time for reveal day,” said Cam, in a report by News.com.au.

“I still think we have taken on too much, but I’ll be proved wrong come auction day when we have some of the most phenomenal luxury apartments we have ever seen in the heart of Prahran.”

Work is already well underway on converting the former headquarters of communication technology company Vixtel.

“Structurally there’s an enormous amount of work that needs to be done before the contestants can even get cracking, which is ongoing,” said Cam, a carpenter by trade.

This season, called The Block Glasshouse, is made even more challenging for contestants who must also turn the ground floor into retail and commercial space.

Couples from the last series of the show walked away with winnings of more than $500,000 each, with winning couple Steve and Chantelle profiting $636,000.