Jump to Content


Can the real estate industry help save the world by preserving resources?

At Entra, we believe that, and we are now building Norway’s first full-scale circular project in close collaboration with IWG Group and their Spaces concept, Futurebuilt and MAD architects. Never, before has anyone in Norway restored or built this size with such a high degree of reused materials. At Kristian Augusts gate number 13 in the city center of Oslo, Entra is refurbishing and adding an infill volume to an eight-story building in Norway’s largest full-scale project with used building materials.

Kristian Augusts gate 13 in the Tullin quarter is a groundbreaking environmental initiative. In this project a 1950s building will be preserved and refurbished with reused materials. The building is part of a larger development of an entire quarter with active passages with art, culture, restaurants and cafes.

Even the concrete slabs and supporting structures in the office building are sourced from buildings undergoing demolition. Reuse of these structures represents major challenges to be worked around for the architects, engineers and building contractors working on the project. Making old building parts fit together, while also meeting today’s building technology requirements, calls for innovation and entirely new ways of building.

There is little expertise in the Norwegian market about reuse in such large projects. For used building materials that lack documentation, we have had to prepare new procedures and moldings to meet current requirements and standards.

The construction and real estate industry is facing the biggest restructuring phase of all time. In order to succeed in reducing our sectors climate footprint we need to shift the industry from linear use and production towards a more sustainable production based on recycling and reuse of existing building stock.

This is KA13
  • Total building area is 4.297 square meters.
  • Existing building is 2.734 square meters.
  • Basement is 708 square meters.
  • Extension is 855 square meters.
  • The standing goal of the project on Kristian Augusts gate 13 is to achieve re-use on the largest scale possible, minimum 50 percent of all materials shall be reused
  • This ambition represents a large reduction in greenhouse gas emissions from materials.
  • Kristian Augusts gate relates to Futurebuilt’s criteria for circular buildings.
  • Kristian Augusts gate 13 works to make the building parts “reusable” when the building later is to be rehabilitated or demolished (for example; bolting steel, proper mortar for brick walls, removable partitions, good traceability of documentation, etc.).