In 2024, decarbonizing and detoxifying the built environment is everyone’s business.
By Sean Vincent O’Keefe
Among the lasting impressions of 2020, a year many regard as the worst in living memory, perhaps the most impactful is the rejuvenated appreciation for human health and wellness as essential to everyday living. Suddenly, everywhere a harsh reality is upon us. The month-over-month impacts of global warming simultaneously soak California and bake Greenland. As sea levels rise, seasonal storm intensity has increased so much that superstorms seem normal. Whereas 30 years ago, the organized push toward a viable human ecology within the built environment launched by the U.S. Green Building Council concentrated on decreasing wasted energy, today, the focus is to decarbonize and detoxify.
Around the world, human dependence on fossil fuels releases carbon dioxide into the air we breathe. Likewise, many products and materials used to build our homes, offices and leisure venues include volatile organic compounds (VOCs) that slowly off-gas over time, releasing carbon dioxide and other toxic chemicals into indoor air. Compounding matters, we routinely use many of these items in proximity to our children, families and friends without a second thought. Stoves, furnaces, HVAC systems, carpets, floors, insulation, personal care products like nail polish and hairsprays, and the furniture wax, detergents, and adhesives used to clean, maintain and repair things are all common contributors to the continual sense of malaise many of us experience every day. Individually, the short-term effects of routine exposure to toxins like carbon dioxide and the formaldehyde, benzene and toluene found in furniture, aerosols and building materials include irritated eyes, noses and throats, headaches, dizziness and fatigue. Long-term exposure to indoor air pollutants can compromise the immune system and contribute to respiratory diseases, heart diseases and cancer.
Whereas 30 years ago, the value of reducing wasted energy primarily impacted building owners, in 2024, decarbonizing and detoxifying the built environment is everyone’s business. The obvious question is: How can we decarbonize and detoxify our lives as quickly as possible. To understand your carbon footprint and how to manage it, first consider the implications of each of the three categories of greenhouse gas emissions.
Scope 1 is direct emissions. These are emissions put into the atmosphere directly by burning fuel from a fossil fuel source like the oil and natural gas used to heat our homes and cook, gasoline and diesel used in combustion engines, and refrigerants in air conditions, refrigerators, freezers and fire suppression systems. Scope 2 involves indirect emissions associated with energy bought from utilities that burn fossil fuels to produce it including electricity from non-renewable sources and the carbon emissions produced by water/wastewater, and other utilities. Scope 3 is likely the largest share of an individual’s carbon footprint. These are the indirect embodied emissions associated with the products and materials we consume and dispose of in end-of-life scenarios every day.
Let’s look at ways to decrease our carbon footprint in each area related to built spaces.
Scope 1: Direct Burned Emissions
Reducing the energy used to heat and cool indoor environments and to store and prepare food is likely the low-hanging fruit for most people interested in decreasing their carbon footprint. However, before investing in solar panels or a geothermal heat pump, start with an energy audit. Such an assessment will determine where a house is wasting energy and target improvements to address specific issues in a logical sequence. Thanks to the Inflation Reduction Act, signed into law in 2022, American homeowners can get up to $1,200 in annual tax credits to cover the cost of an energy audit and related improvements like weather stripping and sealants, energy-efficient windows, and more.
To get a baseline understanding of household emissions, readers can visit the EPA’s Household Carbon Footprint Calculator and input average monthly utility bills to determine a home’s carbon footprint.
Next, decrease the amount of combustion-based carbon you create. There are a few key culprits in the American home, namely the furnace and the stove. A furnace is an item many inherent when they buy a house. A gas furnace will produce roughly a pound of carbon dioxide for every 10 cubic feet of gas burned. Switching from a fuel-fed system to an air-source heat pump when replacing the furnace is wise. An air-source heat pump absorbs heat from outside air and releases it inside like an air conditioner but in the opposite direction. According to the Rocky Mountain Institute (RMI), replacing a gas furnace with a heat pump will reduce carbon in 99 percent of U.S. households. The exceptions are Wyoming and Utah, where electricity remains primarily coal-fired. RMI reports that heat pumps are between two and four-point-five percent more efficient than an ENERGY STAR-certified gas furnace. Installing one will reduce emissions immediately. As the energy grid becomes cleaner, impacts become cumulative. Under the Inflation Reduction Act of 2022, there are up to $2,000 in tax credits and up to $8,000 in upfront discounts for switching to an electric heat pump. Specific individual incentives depend on income level and other factors.
In the realm of the home stove, there are three basic types in the American home. They are gas stoves using natural gas or propane, electric stoves using a coil or ceramic glass, and electric induction cooking. According to the U.S. Energy Information Administration, 38 percent of cookstoves in America burn gas. Whereas gas and electric stoves emit carbon dioxide, recent research found that gas stoves also emit methane gas, even when not in use, making them more of a contributor to climate change than previously understood. While all three stoves produce some carbon waste, induction stoves emit significantly less. An experiment conducted by Paul Scheckel, author of the Home Energy Diet, found that an electric induction cooker released 0.29 pounds of carbon dioxide to boil a pot of water compared to burning natural gas, which released 1.6 pounds. Electric induction cooking is also free of many other indoor air pollutants from gas stoves including nitrous oxides, carbon monoxide, and formaldehyde, which can have negative health effects and exacerbate respiratory conditions.
Scope 2: Indirect Bought Emissions
Reducing indirect emissions associated with the energy that we buy can be as simple as turning off the lights in an unoccupied room or as complex as developing multiple renewable energy sources to achieve grid independence. Unless an architect designed your house to be sustainable and the builder followed through on making it so, there is likely plenty of opportunity to decrease the amount of bought energy the home consumes.
Increasing the amount of natural light throughout a home is a great way to reduce daily energy consumption while also enlivening the living space with biophilic warmth. Adding skylights or larger windows can change the experience of space while enhancing the health and wellness of the people, pets, and plants living within.
When investing in new or replacement windows and doors, homeowners should appreciate that quality makes a difference. Certainly, most products can be understood in terms of good, better and best but when it comes to high-performance windows and doors, the differences can be so significant that the more expensive product can pay for itself over time through energy savings. High-performance windows and doors are key components of an airtight envelope, which is fundamental to increasing a home’s energy efficiency.
Likewise, many American homes could benefit from an upgrade to an intelligent, remotely controlled power panel or electrical box. What started as a fuse box and later became a breaker box is now a digitally controlled smart home system that allows homeowners to rethink electrical consumption through flexible load management. A plethora of smart panel products on the market today allow consumers to harness independently stored energy on demand. Using smart home technologies homeowners can shift energy consumption for things like running the dishwasher, and water heater or recharging their electric car to non-peak hours such as mid-day or midnight when there is typically less demand on the external power grid. In many cases, grid-aware energy consumption will reduce the cost per kilowatt-hour by moving use away from times when demand requires higher time-of-use pricing.
Perhaps the easiest thing you can do in a home or office to decrease energy waste is to make the switch from incandescent light bulbs to Compact Fluorescent Lamp Bulbs (CFLs) or Lighting Emitting Diodes (LEDs) if you haven’t already. Though both LEDs and CFLs are more expensive at the point of purchase, they use about a quarter of the energy of an incandescent bulb and last between 8,000 to 20,000 hours compared to the estimated 1,000-hour life span of an incandescent bulb.
Scope 3: Indirect Embodied Emissions
Scope 1 and 2 equate to operational carbon, or the emissions cost associated with the energy used to operate our homes, offices, and built spaces. Scope 3 emissions represent embodied carbon. These are the emissions associated with extracting raw materials, fabricating something of value, getting it to the consumer, and the expense of using it and disposing of what remains when done. This involves all building materials and services involved in creating your homes as well as all the products, goods, and services we consume as part of daily life. Everything has an embodied carbon cost.
With regard to residential construction, homeowners can make themselves aware of the environmental impacts of the materials they build with. Doing so has never been easier. Many manufacturers issue formal Environmental Product Declarations that detail the specifics related to how the product comes to market including what it’s made of, where and how it is made, and the embodied and end-of-life carbon costs. Homeowners can also research materials through a variety of online resources including the Carbon Smart Materials Palette and the Inventory of Carbon and Energy to understand the embodied carbon costs of many common building products. Rewiring America, an organization dedicated to decarbonizing the economy by electrifying everything, issued a Household Saving Report that proposes to save the average American household between $1,050 and $2,585 a year on energy bills.
Going one step beyond reducing emissions, it’s also possible for homeowners to invest in carbon-negative building materials, meaning products that take more carbon out of the environment than they produce. Natural building materials that undergo photosynthesis draw carbon from the atmosphere and embody it during their growth cycle. When these trees are harvested, the atmospheric carbon sequestered within becomes inert as the wood is transformed into a building material or furniture.
Though reducing our collective carbon footprint will be humanity’s ongoing challenge for the foreseeable future, readers should understand that tremendous power remains with consumers. If we all increase personal awareness of the cost of carbon, the companies that make the things we buy have no choice but to prioritize carbon neutrality in everything we do for the good of us all.
