There is surprisingly little documentation on the collaborative work between architects and engineers. In this publication, we have attempted to redress this balance. For this reason, in our presentation of five timber constructions by the Zurich architects Marianne Burkhalter and Christian Sumi, we have focussed on the technical plans created by Peter Makiol and Roland Wiederkehr's engineering office in Beinwil. These plans illustrate the history of the development and the site operations, as well as highlighting the construction strategies for the prefabrications. The projects have been selected from the last three years and fulfil very different functions: two residential building projects, two pavilions and a roof system on a classicist administration building.Since 1986, Burkhalter Sumi have received widespread public attention, in particular for their timber constructions, and from that time on their designs have played a consistent role in the international architectural debate.