"We now have a supermarket with stock in it, lots of stuff you can buy - you've got a choice.
"It makes it so much better for the people of Featherston," she said.
"I challenge every single resident here to use this facility.
"They've got great staff here, they're people of Featherston.
"You get a smile and a hello, it makes it a great shopping experience."
Trust House chief executive Allan Pollard said it had been a $2.5 million investment and they were "absolutely delighted" with the outcome.
He said three months earlier they had been nervous about the end result, and he reckoned there had probably been some "sleepless nights" for architects Silverwood and contractor Rigg-Zschokke.
"We really tried hard to keep this place trading, because we didn't think it was the right thing to do, to close it down."
He said the staff had been "absolutely magnificent" in coping with the construction works around them.
The morning included three shop-and-grab events, with three residents given one minute to fill their trollies, a free sausage sizzle and face painting for children.
Three organisations, Wairarapa Advocacy Service, Featherston School and Project M Charitable Trust received Trust House donations of $400 each.