Residents of a subsidized housing complex south of Vancouver are wondering how the situation got to be so bad.

There's black mould growing on the walls and windows of their homes in Ladner, and it's a problem they say has been festering for years.

Tania Tisdale and her family were packing their things and heading to a hotel when they spoke to CTV News on Wednesday. They've been asked to leave their townhome so the mould problem can be treated.

The problem has been ongoing since they moved in nearly six years ago, the family says.

"It's gotten steadily worse," Tisdale said.

Photos from inside the home she shares with her partner and four children show the mould along the window frame, on the ceiling and around the baseboards.

Tisdale said her six-year-old daughter has been diagnosed with asthma, and she suspects the mould may be to blame.

"She was a perfectly healthy kid when we first moved in here and within six months of living here she started developing a really bad cough."

The townhouse is one of six units at the complex that has been singled out for remedial work due to mould, according to BC Housing.

CTV first visited Ladner Willows two months ago, when other residents complained the mould was making them sick. At the time, they said the landlord was aware of the problem, but wasn't taking steps to fix it. https://bc.ctvnews.ca/video?clipId=1497018 They say the property hasn't been maintained.

The Ministry of Municipal Affairs and Housing confirmed that officials were notified of the issues in August, and that BC Housing immediately provided funding to the management company to hire a remediation team.

Red Door Housing Society, which manages the complex, was given funds to inspect all 24 units that were tenanted at the time, and results found one unit was inhabitable. The remaining did not require remediation, the ministry said in a statement to CTV.

"Ladner Willows has deficiencies consistent with 'leaky condo syndrome,'" the statement said.

"The building's condition has also been exacerbated by a lack of maintenance over the years and it is in need of major, costly repairs."

The ministry is reviewing the society's maintenance practices at all of the properties in its housing portfolio.

When asked how things got so bad, Red Door executive director Susan Snell said, "I think in a lot of cases it happens pretty fast, and some of (the mould) is hidden by furniture."

She said there's a plan to eventually redevelop the entire site, which just received a $14.6 million funding commitment from the province.

"We've had mould issues for many, many years off and on, and we usually attack them one by one… The building has not held up well over the last 30 years," she said.

Tisdale said it never should have gotten to this point. She's been told her family will be out of their home for at least two days as crews work to clear up the problem she thinks should have been dealt with long ago.

The majority of units at the complex are currently sitting empty. Red Door said when people have moved out they've left the units vacant because of the redevelopment plan. Now that they've secured the provincial funding, they plan to go back to the city to get the process moving.

The new complex will have 146 homes for low-income families and seniors. The society said residents currently living in the complex will be given the right of first refusal when construction is finished.

With a report from CTV Vancouver's Maria Weisgarber