Through his lawyer, Chisnall argued he should instead serve interim supervision while on parole, with intensive monitoring conditions.
Chisnall's lawyer Tony Ellis argued Chisnall was intellectually disabled, facing a multitude of problems including autism, ADHD, depression and PTSD.
Ellis said that proper treatment would reduce the risk of reoffending.
Chief Justice Dame Sian Elias today dismissed that appeal.
She noted that if she granted Chisnall extended supervision with intensive monitoring, she could only order intensive monitoring for a maximum of 12 months.
Elias said evidence included reports from three different psychologists, which all noted that Chisnall posed a "very high risk of imminent, serious, sexual or violent offending".
"This court has accepted that the approach adopted by the High Court and Court of Appeal was correct," Elias said.
"Less restrictive options to interim detention must always be considered, because of the human rights interests affected.
"The court was unanimous in the conclusion that the risks shown on the evidence could not be adequately met by the imposition of conditions, but required the making of an interim detention order.
"The decision of the Court of Appeal was therefore affirmed. The appeal has been dismissed."
The self-care facility where Chisnall is now to continue being held is kept behind fences, but offenders look after themselves.
Three separate psychologist assessments have found he was likely to commit further sexual offending, and one doctor said offending was likely to be "imminent".
Clinical psychologist Steve Berry said Chisnall was likely to commit offences against women and female children.
"Any future offending by the respondent is likely to be in the form of stranger violent sexual acts, against both adult females and female children, and given his impassivity, sexual assaults against known females are also a possibility."
Berry noted that Chisnall had an intense drive and desire to commit sexual offences from an early age.
