Every year 181,000 tons of wood are burned in Denmark, and we use 130,000 tons of new wood in the construction industry. Lendager Arkitekter have an ambition to reduce the use of virgin materials and instead use the materials that we already have. We must build and develop our society, our cities and buildings, and must do it with waste – because waste is our biggest potential resource. Based on this approach, we have developed several materials that work with principles of upcycling and circular economy.

Every time we throw something out, this resource is lost. We have therefore developed a new type of wall panels made out of recycled wood. Wood that normally would be discarded and incinerated has instead been processed and reworked so that it can be used in a new situation and show the way ahead regarding reuse of wood in the construction industry.


Wall panel

2000 m2

Ørestad, Denmark


Solstra Capital Partners




Teknologisk Institut





Partner in charge: Anders Lendager

Project Leaders: Brian Kessy, Kaare Karrebæk Thun


To be able to upcycle wood waste into new concrete products the specific waste fraction must be subjected to several processes and quality assurance tests and analyses. Through a long trial process, we have amassed a lot of experience as well as specific knowledge about handling, processing and documentation of wood waste.

For the project Copenhagen Towers in Ørestad, Copenhagen, we have upcycled 60,000 linear metres of wood that otherwise would have been wasted. The wood comes from window frames, doors, floors and old scaffolding wood. The wood has been collected by our collaborator who has localised and categorized the material, so we can trace the wood back to its source.

Window frames and doors have been split in such a way that the wood can be planed and cut into regular sized strips. The strips have then been sent to be fireproofed to be able to comply with the strict fire regulations for indoor cladding. The wood is fireproofed to class B, S1-D0 by using Burnblock, a 100% organic and nontoxic fire retardant.

The wooden stripes are mounted on a back plate in such a way that the wood strips create a varying surface. The mounted wood is then treated with natural paint that is toned with natural pigments. The finished panels are 500mm wide and come in varying lengths of up to 6000mm without any visible seams.


For the project Copenhagen Towers in Ørestad, Copenhagen, Lendager Group were asked to raise the sustainability profile of the project by covering the interior surfaces with upcycled materials. Not only should the materials be sustainable, they should also fit seamlessly into a high-end, exclusive office setting.

The walls were originally to be covered with glass and aluminium, but thanks to the development of the wood panels, the 2000m2 indoor surface is now covered with sustainable recycled cladding. The wood panels can be found in the lobby and all the way up through the 20 stories of the building around the elevators.

The wood is mainly heartwood, a high quality material that normally would not be available for use in wall cladding.

The result is a surface with a varying relief which plays with light, shadow and small details which all tell a story of what the wood was used for earlier.


The product has set new standards for the development and implementation of upcycle building materials and has been responsible for creating 28 new jobs for a period of five months.

The window wood from the panels is mainly from two large window changing operations, one from southern Copenhagen where the windows are from 1993, and one from Kastrup 1994.


Wood from doors from the first three decades of the 20th century.


Used oil-treated floors from social housing in Gladsaxe, built in 1955.


Worn out and untreated scaffolding pinewood.