The family, who have not been named,Â provide for all the boy's basic needs and personal care, currently have to carry him from room to room at their own risk.
Following and inquiry by the Local Government and Social Care Ombudsman, Doncaster Council has agreed to complete the adaptations required at the family's home, and provide them with other remedies including creating a proper driveway. It will also fund a break for the family.
The little boy has severe disabilities '“Â he is doubly incontinent and cannot walk or move by himself.
He sleeps in a bedroom which is too small to store the special equipment he needs, and there is no room for a hoist to move him to and from his bed.
His parents are being put at increasing risk of injury in moving him as he gets bigger. Work is also needed to improve the bathing facilities on the ground floor.
Michael King, Local Government and Social Care Ombudsman, said:Â 'This significant delay by the council to improve this family's circumstances has caused the family real and tangible distress.
'Family members have risked their own health and wellbeing lifting the boy unaided, and this risk is only going to get greater as the boy grows.
'I'm pleased the council has accepted the recommendations and hope they will now act swiftly to start the home improvements to put an end to the family's distress.'
The family was first assessed by the council in 2014 as needing help with housing and were placed on its accessible housing register.
The home they were originally living in was unsuitable, and had a problem with damp. The council refused to adapt that property as the family did not have a five-year tenancy.
The family finally moved into a council property in August 2017 after their landlord served them with an eviction notice. But they are still waiting for the improvement work to be carried out after a council panel disagreed with an occupational therapist's recommendations about the size of the extension needed to accommodate the adaptations.
The Ombudsman has the power to make recommendations to improve a council's processes for the wider public. In this case the council has agreed to review its policies and procedures to ensure it fully meets its duties to disabled children and their families in arranging adaptations to their housing, based on need rather than tenure.
Damian Allen, Director of People at Doncaster Council, said: "It is clear from the Ombudsman report that the council has failed this family and we fully accept the conclusions and recommendations identified in the report.
"We have met with the family to offer our sincere apologies and explain the actions we are taking to put things right. We are also checking that any other families currently waiting for adaptations have the right action plans in place so these issues do not happen again.'