In short:

Logan City Council has voted to halve its infrastructure charges on one-bedroom granny flats.

Several councillors fear the change will incentivise landlords to create more backyard "slums".

What's next?

The new rules are expected to come into effect in November.

Granny flats will be $13,500 cheaper to build in Logan after controversial new rules were passed by Logan City Council today.

The council voted to halve its $27,000 infrastructure charges for one-bedroom secondary dwellings to incentivise new granny flats.

Logan Mayor Jon Raven opposed the move, saying it would be exploited by landlords to fit more renters into small backyard lots.

He blamed laws created by the Queensland government in 2022 that allowed property owners to rent granny flats to non-family members.

Cr Raven said this was a "loophole" which allowed property investors to build more developments than they would otherwise be allowed.

He said Logan's previous attempts to incentivise more secondary dwellings caused severe suburban overcrowding due to these laws.

"We saw what happened with auxiliary units where you could put a two-bedroom secondary dwelling on the same site as a three-bedroom primary dwelling," Cr Raven said.

"We got slums, and we can still see them in parts of the city today, because we can't remove them once they've been approved.

"Savvy investors will find a way to exploit the discount as best as possible."

Doing the right thing

Councillor Nathan St Ledger supported the move, saying more families wanted to move in together due to the growing unaffordability of housing.

He said council's charges were "bloody expensive" and preventing more granny flats from being built.

He said this would bolster the supply of affordable housing in Logan, even if much of it was run by unscrupulous property investors.

"You've got rocks in your head if you think people aren't going to do it," Cr St Ledger said.

"I completely understand the problem it could cause … but what about the residents who want to do the right thing?"

Under Logan's current rules, infrastructure charges can be waived entirely if the granny flat is connected to the primary house and is used for family members.

The changes are expected to commence in November this year.

The motion passed with the support of eight councillors, with three in opposition and one abstention.

The councillors who opposed were Mindy Rusell, Paul Jackson, and Cr Raven, with Teresa Lane abstaining.