The Highland Council has given the company the go ahead to start on groundworks, foundations, retaining walls, drainage works, landscaping and to upgrade roads.
"The planning process is in two stages and we still have to secure the full operating permit and licence," said Norbord Europe managing director Karl Morris.
Currently the 25-year-old Inverness facility operates two daylight presses. The proposal is to upgrade the plant with a new continuous press and supporting "environmental control technologies".
The company has not disclosed how much the development would increase capacity by, or the cost, although Mr Morris confirmed it would run into the millions of pounds.