Mark Group, which specialises in energy saving installation, bought the New Zealand company from Meridian Energy.
The deal follows Mark Group's growth into Australia and North America in 2009 and 2010 respectively, the business said.
Right House was founded in 2007 as a subsidiary of Meridian, which is a New Zealand electricity generator.
Chris Brazendale, president of international operations at Mark Group, said: "Starting in the UK as a regional company performing home insulation, we have grown to become an energy efficiency expert with a 1,500-strong workforce in 25 worldwide locations.
"The ‘whole house’ approach to energy saving has been at the core of the Right House business since day one meaning that the business is a wonderful fit with Mark Group."
Through the acquisition, all of Right House's employees and operational bases will be retained and Hamish Sisson will remain as chief executive officer.
The acquisition takes Mark Group’s operational bases to 25 and employee count to moer than 1,500 worldwide.