A hundred years ago people with an intellectual disability were locked up in "lunatic asylums". Today they're still locked away, but it's just behind the walls of suburbia.

This is a story I'm trying to write without being able to give you specific details. It includes allegations of sexual abuse, physical assault and degradation, so people have asked for identities to be protected.

So I'll start with what I can tell you. I can tell you that in 2011 the NSW government moved a young woman in with two other people with disabilities into a group home in Sydney and later a fourth.

And what happened next typifies everything that is going wrong in group homes around Australia.

This home was in the city's west. The address is unsurprising because nearly all group homes are located in affordable suburbs. It's here there's suitable houses.

They're also big enough to accommodate up to five high-needs residents in some houses, sometimes with as little as one or two people to care for them.

The parents and carers of those who lived in the house tell me that at first glance it was clear this home would fall apart.

Normally, clients with similar needs are put together in a house. But in this case only two had similar disabilities and temperaments.

From the start, the staff were not able to juggle the needs of the autistic clients, who typically need order, with the other intellectually disabled clients who were more gregarious and acted out.

One mother tells me her daughter was sexually assaulted by another client and nothing was done about it.

She was told it couldn't be proved but her daughter's behaviour deteriorated and she was eventually moved to another home.

This person's mother discover a cigarette burn on her foot. ( Supplied )

But this also proved to be unsafe, with the mother discovering a cigarette burn on her daughter's foot.

At the original house the alleged perpetrator went onto reveal that she herself had been the victim of a physical assault by a worker. Photos were provided. Police were notified but the case didn't make it to court because there were no other witnesses.

This resident was a high-needs client and was so badly managed she would be locked in a garage during one episode.

The worker involved in the alleged assault was sacked. It later emerged that same worker had also been in group homes interstate. Advocates continue to say worker registration, training and screening are pressing priorities.

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Another resident at the Sydney house was a young man with severe epilepsy. As the situation in the home deteriorated, he was moved away but then moved back into the home again.

At the same time his seizures became more frequent and severe and he died from a seizure while on an outing.

His death was the subject of coronial inquiry, which I've seen, and it was found he died of natural causes.

It will never be known whether the constant upheaval contributed to his condition.

These days all the parents and guardians of the residents of this home can only be described as empty shells. They are emotionally and physically exhausted after decades of fighting bureaucracy.

And, now they are facing more change. They must negotiate the National Disability Insurance Scheme. Will it make things better? They hope so, but they're not convinced.

More than 100 years ago people with an intellectual disability were locked away in asylums. Just a short drive north of Sydney the decommissioned Peat Island complex is testament to that.

People with disabilities used to be locked away in places like Peat Island, north of Sydney. ( Supplied: NSW State Archives and Records )

The 1983 landmark Richmond report put an end to that era and people with a disability have been increasingly incorporated into mainstream society since then.

When I first started reporting on conditions in group homes four years ago some advocates suggested to me that group homes had simply become "mini-institutions" filled with the same degradations, abuse and assaults that were common in the old asylums and institutions.

At the time I thought this was an extreme view.

The more I report on this sector and talk to both advocates and families, the more I am convinced that this interpretation is accurate. In some suburbs we've talked to neighbours who report regular screaming, residents who abscond and in one extreme case a break-in from a resident who'd left a nearby house.

Yes, many group homes work wonderfully well. But it's quite clear that just like the home in western Sydney when things go wrong, they go horribly wrong.

And all under the clandestine cloak of suburbia.