'We worked hard to reach the match funding requirements. Now it's a matter of waiting," Mr Anderson said.
In June the gallery received grants of $1 million each from the Whanganui Community Foundation and the S.M. Davis Trust.
The Sarjeant's re-development project is estimated to cost around $34 million. It will include restoration of the existing building, the addition of a new purpose-built wing for storage, exhibitions and education.
The project also includes earthquake-strengthening work, after it was discovered the nearly-century-old bulding had very poor earthquake safety.
In 2014 the gallery made a temporary move from Queens Park to Taupo Quay, where it will remain for several years while the re-development project takes place.