In this article, titled “Their Cape Cod Home Isn’t Small, but Its Carbon Footprint Is,” the author highlights the efforts of a Massachusetts couple, Michael and Jennifer Monteiro, in building a sustainable beach house on Cape Cod. The couple, driven by their passion for combating climate change, decided to demolish their existing house and start fresh with a modern, energy-efficient design. They explored innovative building materials and methods, such as hemp-based insulation and custom concrete mixes, to minimize their carbon footprint. With the help of a team of specialists and a solar array, they successfully constructed a 6,000-square-foot home that produces less than half the carbon dioxide emissions of a conventionally built structure. The article not only highlights their journey but also aims to inspire others to consider sustainable choices in home construction.
Their Cape Cod Home Isn’t Small, but Its Carbon Footprint Is
Introduction
In their quest for a sustainable and energy-efficient home, Michael and Jennifer Monteiro embarked on a journey to build a cutting-edge green beach house on Cape Cod. The couple, motivated by their commitment to addressing climate change, saw their new home as an opportunity to set an example for sustainable building practices. This article explores the challenges, decisions, and innovative solutions they encountered along the way, from demolishing the old house to the construction of their modern, sustainable home.
Background and Motivation
After selling his software company, Michael Monteiro used his investment company, Mpactful Ventures, to focus on projects related to climate change. With a desire to own a home that reflects cutting-edge sustainability, Michael and Jennifer Monteiro purchased a second home in Harwich, Massachusetts. The 1980s oceanfront house posed challenges due to its poor construction and vulnerability to rising sea levels. Determined to have a house that would endure for generations, the couple made the decision to demolish the existing house and build a new structure from scratch.
Initial Challenges and Concerns
The decision to demolish the existing house came with its own set of environmental concerns. To mitigate their carbon footprint, the Monteiro’s partnered with GreenGoat, a nonprofit building-material reuse organization, to salvage usable materials and recycle the rest. They also sought the expertise of Estes Twombly & Titrington Architects to design a modern, sustainable house that retained the aesthetic of a traditional shingled cottage.
Demolishing the House and Salvaging Materials
Working with GreenGoat, the couple ensured that everything worth salvaging from the old house was reclaimed and repurposed. Additionally, they prioritized recycling as much of the construction debris as possible. By salvaging and reusing materials, the Monteiro’s minimized waste and reduced their overall environmental impact.
Designing a Sustainable House
During the design phase, Michael Monteiro questioned conventional building materials and methods to reduce greenhouse gas emissions and prioritize human health. By making careful choices, the couple aimed to create a house that would be energy-efficient and environmentally friendly. They explored alternative options for insulation, foundation materials, and exterior decking to minimize their carbon footprint.
Hemp-Based Insulation
The Monteiro’s discovered hemp-based insulation, known as hempcrete or hemp-lime, as a sustainable alternative to petroleum-based spray foam. This insulation material uses hemp hurd mixed with a lime-based binder, which is then applied as a slurry into wall cavities. Although they faced challenges finding experienced installers in the United States, the couple brought together a team of specialists from France, Canada, and the United States to import the necessary equipment and expertise for applying hemp-lime insulation.
Reducing Greenhouse Gas Emissions
In addition to hemp-based insulation, the Monteiro’s sought to reduce greenhouse gas emissions related to other materials used in the house. They specified a concrete foundation mix with less Portland cement and more fly ash, replacing petroleum-based foam insulation with recycled foamed-glass aggregate, and soundproofing walls with HempWool batts. They also opted for locally-harvested black locust for exterior decking, reducing the need for exotic hardwoods.
Heating, Cooling, and Energy Generation
To achieve energy efficiency, the house incorporates electric air-source heat pumps for heating and cooling. These pumps use electricity to transfer heat energy, rather than generating heat through combustion, resulting in a reduction in greenhouse gas emissions. The home also features a solar array on the roof designed to generate as much energy as the house consumes, making it largely self-sufficient.
Furnishing the Home Sustainably
The Monteiro’s collaborated with Martha’s Vineyard Interior Design to furnish their home sustainably. They opted for renewable and natural materials such as cotton, linen, wool, and hemp, while avoiding plastics and synthetics. To support local artisans and reduce the carbon footprint associated with transportation, they worked with local manufacturers and craftspeople to produce many of the furnishings.
Flexibility for Future Challenges
Recognizing the potential impact of rising sea levels, the Monteiro’s designed their home with flexibility in mind. The finished basement, currently used for recreational activities, has removable walls, allowing it to be abandoned if flooding becomes a problem in the future. This design feature demonstrates the couple’s thoughtful consideration of potential future challenges and their commitment to long-term resilience.
Construction and Cost
The construction of the Monteiro’s sustainable home took approximately two years, with pandemic-related delays contributing to the timeline. The total cost of the project amounted to about $1,200 per square foot. Their investment company, Mpactful Ventures, supported the US Hemp Building Association’s efforts to have hemp-lime approved for residential building codes in the United States, hoping to inspire others to consider sustainable building practices.
Inspiring Sustainable Building Practices
The Monteiro’s home stands as a testament to sustainable building practices and serves as an inspiration for others. Their commitment to reducing their carbon footprint and promoting sustainable design choices demonstrates the possibilities and benefits of environmentally-conscious construction. Through their example, they hope to encourage homeowners and builders to explore sustainable alternatives and make informed choices when it comes to building homes that are both efficient and enduring.
In conclusion, the Monteiro’s Cape Cod home showcases the potential for sustainable and energy-efficient building practices. From the demolition and salvage of materials to the use of hemp-based insulation, the couple embraced innovative solutions to reduce their carbon footprint and prioritize environmental stewardship. Their commitment to sustainability serves as a valuable example for future homeowners and builders, inspiring a shift towards more sustainable building practices.
