David Matthews, CEO of CCS Disability Action, said while a lot of good work had been done in recent years, people with disabilities still faced difficulties in finding suitable housing, employment and education.
"It is not good enough that buildings still have signs up saying, 'Wheelchair access is around the back'," Mr Matthews said.
He said a new disability strategy for New Zealand would be coming out soon.
"This strategy can't sit on the shelf gathering dust; it must be part of everyone's daily thinking. It is a challenge for everyone, especially those seeking office in the upcoming elections."
Mr Matthews said the presence of CCS Disability Action would bring a "more powerful advocacy" to Whanganui.
Other speakers at the opening included Mr McDouall, Les Gilsenan from the Whanganui Disability Resource Centre, CCS Disability Action president Kim Willetts, and the former chair of the Whanganui Disability Resource Centre Mike Ward.
Former Minister for Disability Issues Dame Tariana Turia was expected at the event, but was held up due to other commitments.