Churches today face the challenge of losing their traditional functions in society. However, these landmarks have the potential to become centers of their communities once more. Rising gas prices, strict CO2 emissions regulations, and ineffective insulation make heating churches to comfortable temperatures increasingly difficult. Each community also has different needs and expectations for the use of the building and, as such, different requirements for heating and acoustics. Additionally, the architecture of churches, designed to carry sound throughout their vast spaces, often creates loud reverberations that hinder hosting events. To preserve these monumental buildings for future generations, long-term solutions are required that balance sustainability, comfort, and the preservation of their architectural legacy.

Factors essential to achieving this include the choice of materials, catering to both the space and its people. Fibre Walls is a mono-material stucco layer made from textile fibers sourced from residual waste streams, combined with a biodegradable bio-binder. Developed by Belén in collaboration with HuisVeendam and Kvadrat, this innovative material offers both thermal and acoustic insulation while serving as a decorative layer. Completely circular and biodegradable, Fibre Walls is tailored to each building’s needs, ensuring functionality, enhancing aesthetics, and reducing energy consumption.

The Willibrordus Church has a rich history, rooted in its medieval origins as a gathering place for the farming community of Haringhuizen. Built in the 12th century and expanded with Romanesque architecture in the 15th century, the church underwent significant changes over time, including the demolition of its choir space in 1842. Today, the east wall—once the connection point for the choir—is the coldest part of the structure.

Belén’s design reimagines the lost choir through a wool-based Fibre Walls installation. Drawing from archival plans, the team created a reconstruction of the original choir, which informed the contours of the new wool-insulated stucco wall. The drawing made from wool recreates the choir on the wall from which it once extended. This wool wall restores the memory of the choir, linking the past to the church’s sustainable future.

Wool was an ideal material for this project. Its thermal, acoustic, and moisture-regulating properties make it highly functional, while its connection to Haringhuizen’s pastoral heritage adds cultural resonance. By incorporating wool, the design brings the region’s historical relationship with sheep back into the church, which brings a sense of pride and continuity within the community.

Today, the Willibrordus Church is no longer solely a site for prayer but a space for gatherings and hosting events. At the heart of the church are the people who use it and take care of its heritage. However, like many churches, its traditional design presents challenges for modern use, particularly during colder months. Fibre Walls addresses these issues by creating a comfortable, insulated environment without compromising the church’s architectural integrity.

With over 3,000 churches in the Netherlands expected to lose their religious functions within the next decade, this project offers a model for reimagining historic spaces. By combining innovation and heritage, the Willibrordus Church demonstrates how design can bridge the past and future, ensuring these landmarks remain centers of community life.