"Nothing is changing from our perspective. The good news is that we're really at the heart of the innovation of what we believe will be a major global cloud provider ... Microsoft have recognised the innovation, the passion of the team and they don't want to change that."
Microsoft NZ's director of marketing and operations, Frazer Scott, said the intention was to keep GreenButton's team operating out of New Zealand.
Scott said he was not aware of Microsoft buying another Kiwi startup in the past decade, which made the deal exciting.
Houston said he was committed to stay on at GreenButton, which he called "his baby", until the end of the year.
GreenButton had received funding from NZ Trade & Enterprise and Callaghan Innovation.
The Government's New Zealand Venture Investment Fund had also invested.
Houston said the return from the purchase to NZVIF more than offset the Crown funding the company had received.
NZVIF chief executive Franceska Banga said the sale was "an excellent result for the GreenButton team and its investors".
"The sale - while the deal amount is confidential - has resulted in a very healthy return for the many New Zealand investors.
"When angel investors get cash back, they are generally well disposed to re-invest into the next generation of start-up companies entering the pipeline. So this not only an excellent outcome for New Zealand angel investors but also a good boost for our early stage capital markets."