BABYSITTING: Sitting space is limited, as Alysha Ericksen, left, and Adrienne Hiscoke gather together the nine children of a Phillipstown house.

A people-mover pulls up on a quiet Phillipstown street and five children jump out to join the four preschoolers they live with.

The front yard is suddenly packed with children, most racing to occupy one of a queue of bikes and scooters lined against the house, or the two large trampolines on the lawn.

The youngest two are cradled in their mums' arms to avoid the rush, before they are all peacefully gathered around a little table with clumps of home-made playdough.

This is the after-school scene at a three-family household joining a growing list of overcrowded Christchurch homes.

According to the latest census, more than 162 houses accommodate three or more families, compared to 63 in 2006.

Nationwide, there were 3588 - a more than 1000-home leap from the previous census.

The five-bedroom house holds four adults - two single mums and a couple - and nine children between them.

Danielle Hulse, a solo mother of three children aged 3, 5 and 6, was the original tenant.

Her friend Alysha Ericksen, also a solo mother, moved in with her son just before Christmas because she could not afford her $400 rent alone.

Hulse's brother, partner and five children moved in too after returning to live in Christchurch.

They all help each other out with parenting, childcare, and cooking.

Hulse pays the $350 rent, and the other adults cover the $400 food a week.

Hulse said she would never have imagined living in a house with two other families.

"Not three, maybe two."

Adrienne Hiscoke, who The Press last week reported was being monitored by authorities because of moving her 6-year-old son between too many different schools, said she and her partner joined the household for more stability.

"It's good having that support network," she said.

Finding a house for them and their five children was hard.

"We can't afford it and we need the support."

Hulse said the landlord is trying to sell the house, and when it does they have 42 days to move.

"I finally found a house and now they have put it up for sale," she said. "It's good because of the size of the house and decent-sized backyard."

Despite many applications made, neither of the families has been able to find rental homes cheap enough for them individually, or with landlords willing to take them on as a package.

"We are all looking for a home but have been declined from every one," Hulse said.

"We're hoping to stay together because none of us can afford to go separate ways. [But] we're looking at $600 for another five bedroom, and we can't afford that."