The Bone Marrow Cancer Trust has been operating Rānui House in Christchurch since 1993, but the trust says it had to turn away 664 families in 2023 because the house was full.
Next month it will open the new 43-unit Rānui Apartments complex on Selwyn St.
The new complex has been in the making for 14 years. It will nearly triple the trust's capacity to accommodate patients and families undergoing life-changing treatment.
Trust chief executive Mandy Kennedy said it was heartbreaking to have to turn families away every day because its accommodation was full.
"This is just the unmet demand we know about," Kennedy.
"Many more times travel bookers or families don't even try to book in as they know we have no room."
She said it had been a saving grace during her multiple trips to Christchurch for medical treatment.
Raine has spent 44 nights in Rānui House during five different hospital visits.
Her first stay was in September last year after she had a double mastectomy and implant surgery at Christchurch Hospital.
She said being able to stay at Rānui House was a lifesaver for her, her husband and their two young boys.
"The receptionists, the team of them, they check in every time you go past.
"Checking in how I was doing, when my drains were coming out, how the kids are. They are so friendly."
Raine said her two boys, now eight and four, loved visiting Rānui House and think of it as their Christchurch home which she said made the whole process much easier.
She said it was a relief to know Rānui Apartments will allow many more families like hers to be able to get the support and care Rānui provided.
The trust has also launched a fundraising campaign with the hope of raising around $250,000 to ensure the apartments have extra home comforts to support the families during their visits.
