Last year was the warmest on record, and 2024 is on pace to surpass it as global cities feel the heat. Due to the “urban heat island” effect, cities of a million people or more can be 1.8°–5.4°F warmer on average than the surrounding area according to the EPA, and as much as 22°F warmer in the evening!
Vert render. Image courtesy of Diez Office.
As heatwaves intensify, coupled with dwindling biodiversity in cities across the world, there is an urgent need to rethink urban development and how to keep population centers cool. Vert is an experimental, modular Red Oak structure unveiled this September at Chelsea School of Art during London Design Festival 2024 that addresses temperature and biodiversity in cities.
Devised in a collaboration between the American Hardwood Export Council (AHEC), Stefan Diez’s industrial design studio Diez Office, and urban greening specialists OMCºC, the project proposes a timber structure that helps to cool the city while integrating easily into its existing infrastructure.
Vert consists of tall “sails” covered in climbing plants that work to remove carbon dioxide from the air while creating areas of cooling, shade – sheltered spaces for people to enjoy. Built from sustainable materials, Vert combines aesthetic appeal with tangible environmental benefits, and represents a transformative approach to urban development. The installation is projected to cool the surrounding airspace by as much as 14ºF, cast four times more shade than a 20-year-old tree, and produce as much biomass as an 80-year-old lime tree – all through the use of climbing plants grown over the course of a single summer.
Over the last decade and a half, AHEC has presented a host of experimental structural projects that showcase innovations in hardwood, such as hardwood Cross-Laminated Timber (CLT) and Thermally Modified Timber (TMT). Vert continues this important work, this time focusing on highlighting the potential of Red Oak glue-laminated timber (glulam), an engineered material created by finger jointing and laminating multiple grain-aligned layers of timber to enhance strength and stability. This enables the creation of large, structurally robust components suitable for modern construction.
Constructed from Red Oak glulam, Vert project consists of a series of timber triangles holding suspended biodegradable nets. These provide a framework for climbing plants, rooted in textile planters at the base of each net. The sails create a canopy of around 20 different native plant species, creating a living ecosystem that enriches local biodiversity, serves as a habitat for essential insect populations, aesthetically enriches the urban landscape, and provides a sheltered space where visitors can gather and relax.
“The structure performs as a ‘Greening Machine’, while also making urban spaces more harmonious and pleasant to live in from an aesthetic point of view,” explained Stefan Diez, the Director and Founder of Diez Office. “We wanted Vert to break the monotony of our urban environment.” Vert also features a decked floor beneath the sails made from thermally modified Red Oak. This chemical-free heat treatment alters the wood’s cellular structure, enhancing its durability, stability and increasing its resistance to decay and insect attacks, which makes it ideally suited to use outdoors in urban spaces such as this.
The Munich-based design firm, Diez Office, had been working with OMCºC on their urban-greening solution that would reduce the carbon footprint of the city in the process. This is the role typically performed by trees, but in an era of acute climate change, climbing plants can be more effective as they grow many times faster, require less root space, and can be ‘harvested’ annually to be turned into biochar or recycled as raw material for the generation of energy.
In consultation with AHEC, Diez Office and OMC°C were able to identify Red Oak as the optimal material to use for the project, in terms of both structural performance and ecological credentials. Diez Office has been enthusiastic about the aesthetic possibilities and environmental benefits of Red Oak since learning about the species. Since then, the studio has experimented with Red Oak, first as a furniture material. For this project the whole construction team recognized its structural potential, expanding its application to larger scales.
Despite Red Oak being sustainable and constituting a sizable 18 percent of North American hardwood forests, it is underutilized in Europe. Increased use of Red Oak would reduce the stress on more widely used species and provide designers and customers with an enriched palette of timber materials to choose from.
Because Red Oak is denser and more stable than the standard construction timbers, less material is required, minimizing the visual prominence and footprint of the structure while maintaining high structural performance. The use of Red Oak also allows for more precise and long-lasting joints that enable the structure to be disassembled, moved, repaired and/or reassembled many more times than standard construction materials, supporting the longevity of the piece.
AHEC believes that timber and design industries have important contributions to make in the battle against rising temperatures and diminishing biodiversity in global cities. Vert’s use of Red Oak demonstrates a valuable material option that gives architects a sustainable solution with great structural properties.
“The project is intended to inspire urban planners, architects and designers to address climate change and, above all, to work together to develop interdisciplinary solutions. We want to show that you can implement large-scale greening even in the enclosed spaces of the inner city. Our aim is to create a beautiful place for LDF: a cool, shady, flowering, rustling, buzzing place where you can be close to nature, a garden for insects and people in the middle of the city – somewhere that does you good,” explained Nicola Stattmann, the Director & Founder of OMCºC.
Vert was displayed at the Chelsea College of Art throughout London Design Festival September 14-22 and will remain in place for four weeks afterwards.
