House Rules slashes their winner's prize and no one saw it coming.

After four highly successful seasons of transforming homes across the country, House Rules has returned for another year, but this time, it’s with one major twist.

Previously, teams of two (generally married couples or siblings) competed against one another to win the major prize – the entirety of their mortgages paid off, the promise of a debt-free future was but a few nightmarish months renovating the homes of others away.

Sadly though, due in part to rising house prices and a drop in viewers, the rules have changed in 2017 and now competitors will win a flat prize of $200,000.

Speaking to TV Tonight about the change, a Channel 7 spokesperson said, "We decided to make it a cash prize this year to give the winner the freedom to spend the money exactly how they wanted to."

They continued, “This year’s winner will walk away with their home completely renovated from top to bottom, inside and out, and $200,000 cash in their bank account.”

And while that's still a pretty remarkable prize, it's not clear if this season's competitors knew about the huge change when they signed up or before the season of filming began.

On both Monday and Tuesday night's episodes, contestants spoke about their outstanding mortgage figures and how much winning House Rules would mean for their family.

During its debut episode on Sunday evening, House Rules pulled in just 606,000 viewers - fewer than the ABC's Monday night Australian Story program, and Channel 7's weekly 5pm game show, The Chase.