Design for Freedom works to end modern slavery in the materials supply chain.

By Kamila Grigo

The 2022 Serpentine Pavilion, titled Black Chapel and designed by the multihyphenate artist Theaster Gates, was conceived as a space offering contemplation, community, and joy to the public.

Installed next to the Serpentine South Gallery in London’s Kensington Gardens, the austere pavilion felt at once imposing, as it reached just beyond the treetops, and humbly compact and perfectly embedded within its context.

Thirty-five feet high, the cylindrical structure was capped by a slightly conical, spoke-wheel roof with an oculus at its center. The walkway bisecting the pavilion extended outward from its two entrances and allowed visitors to flow between inside and outside. A bench lined each of the outdoor segments of the walkway, while another lined the pavilion’s interior wall.

The Serpentine Pavilion has been an annual commission since 2000, where contributors, usually architects, are invited to build their first structure in England. This year’s pavilion was constructed using materials that were verified as far up the supply chain as possible to have been produced without the use of forced labor. The calls to action came from Design for Freedom, a report published in 2020 by Grace Farms Foundation to raise awareness about modern slavery in the built environment.

During its run between June and October, Black Chapel invited a range of personal and communal experiences and hosted events, workshops, experimental musical performances, and countless unscripted visits by people from all walks of life. According to Gates, Black Chapel was inspired by various architectural typologies—beehive kilns in the western United States, the Rothko Chapel, English bottle kilns, San Pietro in Rome, and traditional African buildings, including Musgum mud huts and Kasubi Tombs—and by Gates’s interest in how architectural forms enable sacred moments, amplify sound, and hold silence.

Ethically Sourced Materials

But Black Chapel also made a statement about labor and the production of architecture. Gates has said that his interest in architecture comes from the perspective of a builder who works with his hands. The seven tar paintings he made to hang inside the pavilion are an homage to his late father, who was a roofer by trade, and to the notion that labor can be “a beautiful, spiritual way of transmitting energy.” Tar, like clay, is one of the raw building materials that Gates has long used as a medium. Reworked and reshaped through human effort, these simple materials are elevated in Gates’s practice, and it’s fitting that the pavilion was the first completed international Design for Freedom pilot project.

“The question we always like to ask as part of Design for Freedom is: Is your building ethically sourced and sustainably designed?” says Elizabeth Rapuano, the director of communications at Grace Farms Foundation. Geared toward professionals practicing in the building industries, Design for Freedom lays bare the statistics around the humanitarian crisis of child and forced labor and provides reasons why the construction and manufacturing industries don’t always adhere to antislavery laws. “Once you know about the issue of forced labor in the building materials supply chain, you can’t unknow it, and you have a duty to act,” Rapuano adds.

Ethical imperative aside, the report makes the case for proactively sourcing forced-labor-free materials to mitigate business risks. These risks can include damaged brand reputation if found to be using materials produced with slave labor or falling on the wrong side of changing due diligence requirements. Project delays could also occur due to increasing enforcement of legislation such as the U.S. Trade Facilitation and Trade Enforcement Act of 2015, which grants U.S. Customs and Border Protection the power to deny entry to materials and goods reasonably suspected to have been made with forced labor.

The Freedom Toolkit

When Gates was selected to design the Serpentine Pavilion, Design for Freedom approached the Serpentine Gallery, recognizing how Gates’s focus on materiality could overlap with a Design for Freedom pilot project. The Serpentine “was so willing to jump in and address this issue of tracing materials,” says Nora Rizzo, Grace Farms’s ethical materials director. The collaboration moved forward, with Grace Farms Foundation brought on as responsible materials adviser to work with the Black Chapel team to audit materials using the Design for Freedom Toolkit.

The tool kit is a set of resources and tools developed to guide designers, architects, and other professionals in the built environment through the process of materials tracing. Rizzo, who led its development, formed a steering committee of partners who were either Design for Freedom working group members or experts in material supply chain sourcing. The steering committee included the sustainability consultant Charley Stevenson from Integrated Eco Strategy; Bill DuBois, a specification writer at Gensler; Jane Abernethy from the manufacturer Humanscale; and the architects Jason Jewhurst at Bruner/Cott Architects, Jared Gilbert at COOKFOX Architects, and James Slade, Hayes Slade, and Greg Bencivengo at Slade Architecture.

When they were developing the tool kit, Rizzo says, “We asked questions such as: Who would ultimately be using the tool kit? What resources would be helpful to organizations that are just starting out on their transparency journey?” The committee then put together a draft tool kit, applying it on the pilot projects that had just been launched and refining it based on real-time feedback from the pilot project teams.

The resulting tool kit, available for free download from the Design for Freedom website, is organized into three sections: Education, Commitment, and Implementation. A substantial chapter in the education section is devoted to the top building materials at risk of embedded slavery, which include stone, timber, steel, iron, and the calcium carbonate used in cement or mortar. For each of these high-risk materials, the countries of provenance are listed if they’re child- or forced-labor hot spots. Also included are explanations about production methods and conditions, end products and applications, and relevant certifications—all of which assist with responsible sourcing.

To help design professionals start discussions with their clients and project teams about adopting ethical material procurement, the commitment section includes overview and principles documents that are concise descriptions of the Design for Freedom initiative and its goals. The implementation section of the tool kit is the most hands-on and includes an action plan, an ethical design requirements specification, a relevant certifications list, a draft letter and product questionnaire for outreach to suppliers, and a material tracking schedule to document the responses from suppliers and manufacturers.

Material Audit

On Black Chapel, Rizzo worked closely with Cormac Clerkin Parr from AECOM, the infrastructure consultants who have served as technical advisers on the Serpentine Pavilion since 2013. Clerkin Parr, an associate project manager responsible for the day-to-day management of the project from design through construction, says, “We were very lucky to have the involvement of Grace Farms” from the very beginning. The time constraints of the Serpentine Pavilion as a six-month design/build forced the team to take a strategic approach to which materials would be audited. “We narrowed down the list of materials we would track to target those big winners in terms of overall quantities,” Clerkin Parr says. “We had an early engagement from the contractor, Stage One, to ensure they were coming on this journey with us, and they flowed that down to their supply chain.”

The team credits this early buy-in and understanding as factors in the material audit’s success, as well as direct access to Stage One’s strong network of small- and medium-sized suppliers.

The materials selected for auditing were plywood and timber, steel, concrete, and the rubber membrane used to weatherproof the structure. With oversight from Rizzo, the team adapted the supplier questionnaire to the United Kingdom market and the materials selected for auditing. For example, given the amount of timber being sourced on Black Chapel, they made sure to include points about forestry certifications, using the relevant certifications list as a reference. The team also used the materials tracking schedule, tailoring it slightly to the needs of the project, to catalog the information as it came in.

“We had fortnightly review meetings with Grace Farms to provide them with updates,” Clerkin Parr says, while internally they held weekly meetings to review where information was outstanding. The contractor was required to submit information weekly, and Clerkin Parr says the team reviewed all the certifications that were provided to ensure they were relevant. Ultimately, materials were audited as far back as their primary supplier and in certain cases up to raw material extraction. When it came time for procurement, order numbers and delivery details were cross-referenced with the information originally provided by suppliers.

The Tracking Process

A key experience came by way of the weatherproofing membrane, which the team wasn’t able to trace all the way to raw material suppliers. It highlights the challenge of achieving supply-chain transparency in a global network of suppliers, purchasing agents, and vendors of the raw materials used to manufacture more processed materials and products that end up on building sites. The membrane, which is composed of eight different elements, was sourced from a larger U.S. manufacturer who in turn sourced the raw materials from multiple suppliers around the world. “We kept chasing this one up until, I think, a week prior to handing over the pavilion,” says Clerkin Parr, adding that the certifications the supplier provided contributed to an overall positive assessment.

Black Chapel’s small footprint and the relatively raw materials that were specified made the tracking process manageable.

Jon Leach, a technical practice lead for structural engineering and a project director at AECOM, acknowledges that the process would be more challenging on larger projects that use more intricate products and systems. Leach, who has led the AECOM teams on Serpentine Pavilion projects throughout the years, puts ethical materials sourcing in the context of sustainability and the focus on low carbon, noting that the project went through two rounds of life-cycle assessments. “As part of that process, we’re obviously cognizant of the sourcing of materials,” he says, adding that “it’s a discussion I’m planning to have with our sustainability team to say, if they’re going through this process of interrogating supply chains for energy performance certificates and embodied carbon, can we do, in parallel, the process of ethical sourcing?” He also plans to speak with his specifications team to see how the ethical design requirements specification from the tool kit might be incorporated. Ethical sourcing is just another aspect of the discussion about building materials, and going through the pilot project has put AECOM in a good position to steer the discussion in the right direction on future projects.

The Design for Freedom movement continues beyond the report and the pilot projects. The working group is looking at the digital tools needed to model, document, and verify supply chain transparency, and Rapuano says that partnerships are being explored with organizations such as mindful MATERIALS to incorporate ethical filters into material databases and libraries. The next Design for Freedom Summit is scheduled for March 30, 2023, and a few landscape-specific pilot projects are also under consideration. “You really can feel the momentum right now—it’s an incredibly hopeful moment,” she says.

Kamila Grigo is a landscape architect who writes about landscape architecture projects as a method of design research.

Clarification: Two captions in the online version of this article were updated from the print version to replace the words “rubber” and “weatherproofing” with the words “weatherproofing membrane.”