Since the early 1980s, Friedl has written on a variety of subjects. The book Secret Modernity: Selected Writings and Interviews 1981–2009 compiles for the first time a representative selection of his (partly unpublished) texts, along with a series of interviews.

Die heimliche Moderne brings together a collection of Friedl’s writings and interviews from 1981–2009. It is available in both English and German editions.

Working at Copan collects interviews with workers and employees at Edifício Copan, a landmark modernist architecture in the center of São Paulo. Designed by Oscar Niemeyer and completed in 1966, it became the largest residential building in Latin America. As a historical building and symbol of “vertical utopia,” it embodies an era of radical political and economic changes within Brazilian society.

In Four or Five Roses, some 45 narratives by children are presented in the form of a monologue. Edited from numerous interviews and conversations recorded on playgrounds in South Africa, Peter Friedl creates a hybrid genre that is both fictionalised speech and serious counter-voice.