Introduction

Why Soil Matters

The architecture, engineering, and construction industries have a myriad of opportunities to improve the health, sustainability, and resiliency of the built environment in Massachusetts. The building sector is the second largest source of greenhouse gas emissions in Massachusetts, at 35 percent (OEEA 2022). The Commonwealth’s main building decarbonization strategies hinge on maximizing energy efficiency and transitioning heating from fossil fuels to renewable sources of electricity. The use of high-performance building technologies, tight thermal envelopes, and lower emissions building materials are the main strategies for achieving the ambitious goals set by the Commonwealth’s 2025/2030 Clean Energy and Climate Plan (CECP).

However, these widely accepted strategies to minimize the embodied carbon footprint of development projects overlook a foundational element of the built environment: the soil, the very ground we build on. The way we design and construct buildings and landscapes can impact the overall net carbon emissions of a development more than all the energy, materials, and long-term use combined. 

Including healthy soil management practices as part of the overall effort to decarbonize the building sector could prevent unnecessary carbon from being released into the atmosphere and increase long term carbon sequestration and storage capacity in existing and new construction. Limiting soil disturbance and maximizing the Soil Organic Carbon (SOC) sequestration potential is the only way a development site can truly become carbon neutral or a carbon sink. The protection and restoration of healthy, high-functioning soils onsite is an underutilized approach for developers who want to reduce the carbon footprint of the building sector and bring greater coherence to our ability to live and thrive in both urban and rural environments.

The Benefits of Healthy Soil

Healthy soils increase drought resilience, mitigate flooding, adsorb excess nutrients, filter sediments, decompose pollutants, and moderate peak stream flows and temperatures. Healthy soils also perform important stormwater management functions; they increase water holding capacity and support vigorous plant and tree growth that intercept rainfall, returning much of it to the atmosphere through evaporation and transpiration. Preserving and enhancing healthy soils during the construction process can prevent expensive problems such as poor drainage, nutrient leaching, and erosion from developing later on.

Protecting soils and minimizing soil disturbance should be a primary objective in reducing the embodied carbon footprint of the construction process; however, disturbance cannot be entirely avoided in the built environment. Building and construction is, by nature, a disturbance event that disrupts biological, geological, and chemical cycles in the soil. Disturbance is also a natural and even necessary component of high-functioning ecological systems, not unlike periodic wildfires and earthquakes. With proper planning and a better understanding of healthy soil functions, we can use the necessary disturbance of construction to intervene and improve soil function.

Designing and building “soil-smart” developments means working with the cycles of natural ecosystems and actively situating human activity within the larger story of dynamic ecological processes.

Humans are not only consumers of natural resources, but also catalysts for transformation that can either prevent or fortify the mutual flourishing of life both above and below ground. We have an incredible opportunity at hand to design our built environment to protect, serve, and enhance the natural environment.

Why This Guide

Over 360,000 additional acres of soil in Massachusetts may be impacted by development over the next 35 years (HSAP 2023). Every time soil is disturbed, SOC is transformed into carbon dioxide and lost back into the air. Every ton of SOC is the equivalent of 3.677 tons of carbon dioxide. Agricultural research is fueling a movement toward no-till agriculture, but this science is just as applicable to the soil disturbance in site development and landscaping services. The difference developers and construction professionals can make is significant: there is roughly twice the amount of land in turf and ornamental landscapes in Massachusetts as agricultural land. Shifts in design and management practices—such as planting 25% of open lawn with trees, and increasing organic matter content in the top 8” of lawns to a minimum of 3%—could sequester an additional ~180,000 tons of carbon dioxide equivalent per year, the same as taking over 38,000 gas-powered passenger vehicles off the road.

There is a wealth of information, guidance, and ongoing research into building healthy soils. Yet, it is not straightforward for those in the building industry to apply them, and soil health is often overlooked in the development process. During final grading, a minimal layer of topsoil may be brought in to cover the site and install aesthetically pleasing vegetation, hiding the damage of disturbance from view. However, the underlying damages to soil health often become visible after the project has been completed in the form of issues such as poor drainage, erosive runoff, and failed plantings that make long-term management difficult and resource-intensive. Poor soil health outcomes are invariably more carbon-intensive as well.

This guide strives to synthesize the most impactful ways to intervene within today’s design and construction practices, and address some of the challenges that design and construction professionals face in integrating healthy soil practices into their work:

This guide aims to bridge these gaps for design and construction professionals by recommending healthy soil standards and specifications, along with recommended best management practices from a variety of disciplines in plain language for professionals across the construction industry.

The Massachusetts Healthy Soils Guide was produced by Regenerative Design Group in partnership with Linnean Solutions, BSC Group, and Sasaki, and funded by the Massachusetts Healthy Soils Challenge Grant through the Executive Office of Energy and Environmental Affairs (EEA). It is published in print and in digital format to ensure it stays up-to-date and accessible to a wide range of users, who will help raise the profile of soil health and the enormous untapped potential of optimizing healthy soil functions throughout the design and construction process.

Establishing “Soil-Smart” Project Goals

What is possible when it comes to protecting, managing, and enhancing soil health and function? What is a “soil-smart” design, and how can planners, designers, and contractors all work together to use “soil-smart” practices that prioritize healthy soil outcomes?