Families of children being treated at a Bristol hospital that is far from their homes will be able to stay in new accommodation units.
Bristol Children's Hospital said the "home-from-home" which has opened was a "lifeline" that has nine en-suite rooms, kitchen and laundry facilities.
The house was built and funded by the hospital's charity The Grand Appeal.
Lauren Jenkins whose daughter Evie has spent nine months in hospital said "it makes a massive difference".
Nicola Masters, from The Grand Appeal, said it meant families had "one less thing to think about".
Ms Jenkins, from Cornwall, said two-year-old Evie is being treated at Bristol Children's Hospital after a brain tumour left her with complications.
"It's been quite a long time, quite hard, it's been a long rollercoaster.
"We're away from home because we're from Cornwall - all our friends and family are down there," she said.
"Some days are really tough and it's really nice having somewhere to escape all the frustrations of the day."
Nicola Masters said: "Bristol Children's Hospital and the neo-natal unit cover the largest geographical area of any children's hospital in England.
"That's right down to Cornwall, as far down to the south coast into Dorset, through into south Wales and right up towards Birmingham.
"So when you consider that's such a huge area, if your child needs to be transferred to Bristol for the specialist treatment they provide, then you need somewhere to stay close by."