The $3.5 million purpose-built centre is being bankrolled by the not-for-profit John James Foundation, Canberra's largest medical charity, which uses funds from the $100 million sale of the Calvary John James Hospital and other assets in 2018 for philanthropic causes. The lease on the land for the centre in Garran was gifted by the ACT Government.

The autism hub will be owned and operated privately by the AEIOU Foundation. Construction will start this week, with the centre due to be open by early 2021.

The centre will cater for autistic children aged between two and six years who will be supported by a specialist team comprised of speech pathologists, occupational therapists, behavioural therapists and early childhood educators, all located in the one location.

John James Foundation chief executive officer Joe Roff said talks started with the AEIOU Foundation two years ago to bring its services to Canberra.

"Canberra families have previously relocated to Queensland to access these services," he said.

"Families will now be able to stay close to family and friends, with the autism-specific support the need."

Isabella Plains couple Brian and Katy Meilak were one of those families who went to Queensland to seek out the AEIOU services for their son Zachary, who has autism.

Mr Meilak lived in Brisbane with Zachary for an year in 2015, while Mrs Meilak stayed in Canberra with their daughter Lily, a high-functioning autistic child.

The year of separation was difficult but "100 per cent worth it", Mr Meilak said. His son was exposed to all kinds of support, to the extent Zachary, now 10, attends Bonython Primary, in the learning support unit, able to communicate better and be more independent.

"I think if he hadn't done the program, he would not have developed as far as he has and the stress in the family would have been immense. A lot of couples with children on the spectrum separate because there is so much stress and tension," he said.

"The centre is not a cure. But it does help children manage their challenges. Zachary will always have challenges, but today, he's a totally different child.

"AEIOU works with the child and the family and it really does help keep families together."

Zachary was diagnosed with autism when he was four. Mr Meilak said the introduction of the National Disability Insurance Scheme in the ACT in 2014 saw many services in Canberra for autistic children close, leading the family to have to try AEIOU in Brisbane.

"It was hard having our family separated in two but it was something we had to do," Mr Meilak said.

AEIOU chief executive officer Alan Smith said the children would attend the centre five days a week in an environment similar to a childcare centre or kindergarten, learning the skills that would lead to school.

"We start with the very basic rules around toileting and communication and behaviours and then move to the more academic skills," he said.

Mr Smith said AEIOU was an approved NDIS provider. Fees were usually covered by an NDIS package but because the childcare subsidy applied, each family would have to pay some amount, based on Federal Government outlines.

Most children stayed in the program for two years. Children were accepted on a "first in, first served" basis with others put on a waiting list.

But Mr Smith said the waiting list was then subject to whose need was deemed the greatest and which child was the best fit for the centre.

Project Coordination will design and construct the new facility on the corner of Curlewis Crescent and Rusden Street in Garran.

Mr Roff said the $3.5 million would cover the "bare bones" of the new centre. The John James Foundation would be looking to the "goodwill of the community" and its suppliers to ensure the centre had everything covered, including landscaping and playground equipment, he said.