Other special guests and speakers at the opening included Hurunui-o-rangi marae representative Ra Smith, Carterton Mayoress Julie Booth, property consultant Ian Rattray, school trustees, parent support and whanau support group members, students, teachers and non-teaching staff.
"A clear sense of positive feeling about the school continues to be evident and the students are benefiting from being in a positive modern learning environment, and a unique one with the two educational pedagogies and philosophies working side by side," Mr Kay said.
"Certainly in Wairarapa, the school is unique in what is offered and the school is rapidly growing a sense of togetherness, a sense in which all are able to enrich each other and learn from one another. This is a very rich and powerful asset as South End School continues to move forward."
Staff joined Mr Kay in a waiata ahead of a performance from the school kapa haka group, which comprises nearly half the roll.
Mr Kay said the colour schemes of the new building closely matched the block that was refurbished 18 months ago, except for the internal walls of purple and orange in the library that created "a warm child-friendly environment for the students. He spoke as well about the impact the new block will have on pupils and staff and on the school community.