A law change means it is no longer illegal for people with intellectual disabilities to have sex.
Previously, having a sexual relationship with a person who has an intellectual disability was deemed criminal because it was assumed people with intellectual disabilities could not consent to a sexual relationship.
The new rule will instead consider whether a person who has an intellectual disability has the capacity to consent to a sexual relationship, rather than banning such relationships outright by reason of the person's intellectual disability.
A new category of "protected person" has been created to prevent exploitation and to specifically state that it is against the law to have sex with someone who is incapable of understanding the activity.
Rehab's director of communications Kathleen O'Meara said: "While, it is the case that this new law could have gone further to create a more disability-neutral law, we believe this change in the law will provide greater opportunities to people with intellectual disabilities to assert their human right to marry and to found a family.
"It will also open access to essential sex education and sexual and reproductive health services for people with intellectual disabilities just like everyone else."