Buildings and facilities require a large part of the earth's resources in terms of materials, energy and waste. Kristian Augusts gate 13 (KA13) is largely created from elements that would otherwise have been thrown away.

This is Norway's first building where the reuse of building materials and circular solutions has been used on a larger scale. With this project, the amount of waste has been drastically reduced, both through the reuse of the existing building and through the use of materials from demolition projects. In addition, the preservation and further development of existing buildings and urban spaces is valuable for the cities' identity and history.

The houses from the 1950s can quickly disappear as they have low floor heights and are complicated to upgrade to today's technical requirements. The construction industry is often featured as the 40% industry, using 40% of resources, creating 40% of the waste and 40% of emissions. There is a dire need to increase reuse and recycling within construction.

The building as well as the newly built extension is created by reusable materials coming from various "donor buildings" (ie buildings that were either to be demolished or rehabilitated). The facade panels from renovation projects in Trondheim and Oslo, concrete decks from government building R4 and windows from a wrong order to Kværnerbyen. Old lattice plates from Tøyenbadet have become railings, and the terrace decks are in natural stone from a rehabilitated facade on Skøyen. Old radiators, doors, wall coverings and even furniture have been salvaged from the original building and nicely restored. In addition, the focus is on reusability, ie elements, both new and existing, are suitable for further reuse in a possible next round.

The building has changed the way of thinking about what can be reused, even with complex conditions. The modest office building from the 1950s has been preserved instead of demolished. In addition, an extension has been erected which largely consists of reused building materials.

Based on the experiences from Kristian August gate 13, an experience report has been prepared that will make it easier for others to follow in the same footsteps. The sharing of these experiences is elementary for such projects to help revitalize the knowledge around reuse and reuse of building materials.