A project in the Netherlands is exploring the use of circular materials in architecture. In collaboration with NPSP Delft, the Dutch water authority Hoogheemraadschap De Stichtse Rijnlanden (HDSR) has developed facade panels using cellulose recovered from wastewater treatment. Designed by Schoots Architecten, these panels comply with building regulations and demonstrate the application of sustainable and circular construction methods.

The initial implementation of these panels is on an HDSR office building in De Meern, serving as a case study for architects, developers, and construction professionals. The project aims to integrate circularity, durability, and aesthetics to illustrate the potential of reclaimed materials in sustainable architecture.

Reclaimed Toilet Paper and CO2 Reduction
Annually, approximately 180,000 tonnes of toilet paper are flushed in the Netherlands. This paper contains cellulose, a biobased raw material traditionally sourced from trees and plants for use in paper, cardboard, and building insulation.

Recovering cellulose from used toilet paper reduces deforestation, conserves energy, and lowers CO2 emissions. For the 200m2 facade in De Meern, reclaimed cellulose from 2,000 rolls of toilet paper has been used, reducing CO2 emissions by 10 tonnes compared to a traditional brick facade, equivalent to preserving ten trees.

According to Nanda van Zoelen of HDSR, recovering valuable raw materials from wastewater treatment is a focus area within the water sector.

Climate-Neutral and Circular Construction
Climate change is increasing pressure on water resources, with heightened risks of flooding and drought. HDSR has set objectives including achieving energy neutrality by 2030 and full circularity by 2050. In addition to reusing materials and reducing CO2 emissions, recovering cellulose from wastewater treatment decreases residual waste discharge into surface water.

Wastewater as a Resource for Energy and Materials
Wastewater treatment yields byproducts that can be used in construction and other industries. In addition to facade panels, reclaimed cellulose can function as a binder in asphalt, while treated water can be used for building heating. Another byproduct, Kaumera, is being examined for applications in agriculture and as a fire retardant in facade cladding.

Material Properties and Applications
The facade panels developed by NPSP Delft from reclaimed cellulose are designed to be durable and stable. They are resistant to UV radiation and adverse weather conditions, with an expected lifespan of at least 50 years. The panels comply with fire safety regulations, and their design by Schoots Architecten highlights their potential applications in architecture.

HDSR encourages project developers and construction companies to explore the possibilities of using this material in sustainable building projects.

Source: Hoogheemraadschap De Stichtse Rijnlanden
Image: Hoogheemraadschap De Stichtse Rijnlanden