As more garden and landscape designers aspire to create sustainable gardens, there’s one significant but often ignored aspect of sustainability they should pay attention to: hardscape materials. For most landscapes, the materials for the decks, patios, paths, and stairs will make up the vast majority of the project’s carbon footprint.
When people think of carbon footprint they often think of actions like driving a combustion engine car and flying on airplanes, but materials also possess an embodied (or upfront) carbon footprint. The “embodied” carbon is not, in fact, embodied in the material. Rather, it is an estimate of the emissions that come from making the material and shipping it. Unfortunately, some of the landscape industry’s favorite materials, including concrete and tropical hardwoods like ipe, have a high embodied carbon. (Taking in all stages of production, concrete is estimated to be responsible for 4 to 8 percent of the world’s CO2.)
“I don’t think clients are aware of the carbon footprint that concrete has,” says Sara Brunelle, co-founder of the landscape design firm Lu — La Studio, based in Cambridge, MA. “People are interested in pollinators and ecological properties, but they’re not really thinking about the material implications of their project.” However, homeowners and designers alike should consider the climate impacts of the materials they choose for their gardens.
We spoke to experts who are designing with low-carbon hardscape materials to ask them for their best advice when it comes to low-carbon hardscapes. Here’s what they said.
Less is more.
Want to lower the carbon footprint of your landscape? Use less hardscape material. It’ll also be better for the environment overall. “Hardscape mostly prevents water from returning to the earth—and water returning to the earth is the first thing that has to happen in order to support or create life,” says David Godshall, co-founder of Terremotto, a landscape architecture studio with offices in northern and southern California. “So, the more hardscape a garden has, the more lifeless it is.” Of course, gardens need paths, patios and the like, but Godshall encourages garden designers to ask themselves what is the minimum amount of hardscape needed to make a space useful and enjoyable to everyone, including people who are differently abled.