Music star Shania Twain has revealed how she put her "heart, soul and dreams" into her New Zealand home - while her husband was having an affair with his secretary.

The Canadian country singer, 45, has written a tell-all memoir about the end of her 14-year marriage to producer Robert "Mutt" Lange after his affair with her close friend, Marie-Anne Thiebaud.

Twain ended up marrying Thiebaud's former husband Frederic.

In the book, From this Moment On, she writes about Motatapu, the couple's high-country sheep station near Queenstown.

"I started designing a homestead for us shortly after we bought it and began putting my heart, soul and dreams into the plans," she said. "I dreamed of riding horses across the vast plains, along winding riverbanks and through golden tussocks in the sharp, beaming sunshine of the land of the Kiwi."

The pair bought the 24,731ha Motatapu Station and Mt Soho for $21.5 million in 2004.

"Every year Mutt, Eja and I would go there for several months, living in a small caravan parked in one of the sheep paddocks...we enjoyed camping out while our home was being built."

She returned from her home in Switzerland in early 2008 to finish the project.