In recent years, Henning Larsen has planned for five large-scale residential projects in Copenhagen and one elementary school in Aarhus to be built with recycled brick facades. This choice of materials in the six Henning Larsen buildings combined represents a total saving of 1.15 million kg of CO2, compared to when using new bricks. That is equal to the emission of 10,000 one-way flights between Copenhagen and New York City.
The comparison of the new vs. recycled bricks is based solely on activities in the production phases as defined in the EU standard for sustainability of construction works, EN15804. One ton of newly manufactured bricks releases 258 kg of CO2 emissions, whereas a ton of recycled bricks emits 2,7 kg. It means that new bricks emit 95 times more CO2 in its production than recycled bricks.
The construction phases for new bricks this includes procurement of all raw materials, products, transport and energy used in production, packaging, internal transport and waste disposal. For recycled bricks, the production phases includes harvesting the historic bricks from the original building, transport to the cleaning factory, the rinsing process at the factory, and the transport and disposal of waste
“It is paramount for architects to be part of the climate solutions, and choosing the right materials can mean extraordinary savings in energy use and CO2 emissions. This requires analytical life cycle assessments in the material selection process,” material expert at Henning Larsen, Martha Lewis says.
The major environmental impacts in using recycled bricks is a strong argument for choosing previously used brick in new facades, Martha Lewis says.
“But our choice of using recycled brick in the six projects was also inspired by the appealing appearance of the historic bricks, and the compelling thought of recycling history. At Frederiksbjerg School in Aarhus, some of the bricks are from an old county hospital that locals will remember. It gives the school a rich architectural expression that enhances the new buildings’ position within the urban context,” she adds.
The six buildings are the Frederiksbjerg School in Aarhus, two residential projects at Islands Brygge (Pollux + Castor), the Jacobsen Hus in the Carlsberg City, a residential project at Sandkajen in Nordhavnen and the Nimbus youth residential project in Frederiksberg, Copenhagen.
About the data:
It is now possible to compare the environmental impacts of products within similar categories in a life cycle assessment based on data that has been published in an Environmental Product Declarations (EPDs). The data for our brick comparison derives from an EPD for recycled Danish bricks and is compared with an EPD for newly manufactured Danish bricks. The data in both EPDs has been verified by a third party, and the documents are available on Technological Institute’s website, epddanmark.dk.