The construction industry uses three quarters of all the raw materials used by the United States, while buildings consume nearly 40% of energy in the country, more than both transportation and industrial sectors. Almost half of the greenhouse gas emissions stemming from buildings are due to materials production and the burning of fossil fuels. The process of construction creates a lot of waste, contributing between 30% and 40% of domestic landfill waste.
The current state of construction and the role of the construction industry in Los Angeles is complicated, and is connected to issues of climate change, affordability, and overcrowding, for starters.
Over the last century, the demand for materials relative to population has tripled, and coupled with rapid urbanization and population growth—leading to housing crises in big cities like Los Angeles—this poses major environmental justice and equity issues in the face of climate change. In Los Angeles, buildings account for 43% of the city’s emissions. This number is much higher than that of the US average—30%—as well as higher than the average city in California, 25%. One reason why buildings make up a higher percentage of LA’s total emissions is because of developers and firms who cater to high-income buyers at environmental cost.
The median price for a house in Los Angeles is $700,000, while the median household income is only $58,000. High-end developers sell these homes for tens of millions of dollars, far outside the budget of most Angelenos. The building of unaffordable homes that take up huge amounts of space and drive up average neighborhood prices exacerbates the housing crisis. In 1950, the average single-family home in the US was 983 square feet, a fraction of the scale that these new homes are being built at. The oversized proportions of these McMansions stand out like a sore thumb among neighborhoods of smaller, Spanish style houses built in the early twentieth century.
For the past thirty years, Los Angeles has been the country with the most-overcrowded housing in the country. Today, 11% of homes in the county are overcrowded, meaning there is more than one person per room (excluding bathrooms). The overcrowding rate in LA is more than triple that of the national figure. In Pico-Union, for example, 40% of homes are overcrowded. At just 1.33 square miles, and home to around 40,000 people, this neighborhood has a higher population density than New York City. The major difference? While New York is filled with multi-use buildings and skyscrapers, LA building codes have severely limited where developers can build taller buildings (away from affluent areas), meaning it is harder to sustainably and affordably house families.
Los Angeles—and the country at large—is in the midst of a housing crisis. There is a shortage of affordable housing, which has many consequences. It isn’t just that houses are growing increasingly expensive. The city’s surging unhoused population is evidence of this. In a University of Southern California survey, more than 73% of Angelenos were rent-burdened, meaning they spend over a third of household income on rent and utilities. Almost 50% of respondents were severely rent-burdened, with more than half of their income going towards rent and utilities. So as housing prices increase and real wages fall, Los Angeles must address its affordable housing crisis.
This is a daunting task, especially in California. There are so many rules and stages of permitting and regulation to get a construction project approved, all of which rack up the cost of a project. In San Francisco, for instance, new construction takes up to four years to get all the necessary permits. Even though the rules might all make sense individually—preserving historic neighborhoods, ensuring affordable housing is built safely, and keeping the environment in mind—all together, they end up requiring so much time and money to overcome them that they essentially block new construction. This is especially impactful in the realm of affordable housing, because if it’s not affordable to build the affordable housing, then much less of it gets built.
American federal tax law is designed to incentivize home ownership. However, today, the US has fewer homes per thousand residents than the European Union’s average. As people are unable to afford housing in the city, they are pushed out towards the suburbs, increasing dependency on cars and upping carbon footprints.
Los Angeles is a car-centric city, sprawling across a huge expanse and crossed with multi-lane freeways. The loss of green space coupled with the substitution of concrete and asphalt creates exposed surfaces that capture heat and raise the temperature in the surrounding areas. These raised-temperature areas are called hotspots, and they can get up to 32°F hotter than other parts of the city. So not only does the city practically require the use of automobiles—and their emissions—but the very infrastructures themselves perpetuate a warming climate.
In terms of the city’s construction sector, there are many implications. For one, heat and humidity reduce worker productivity. During an average year, it is estimated that heat costs the Los Angeles area nearly $5 billion in lost output due to reduced worker productivity. A second implication is that construction workers spend the majority of their workday outside and around exposed, heat-trapping surfaces—hotspots—meaning that they are disproportionately affected by heat.
Another factor is that materials costs are rising. Even pre-pandemic, when global supply chains were disrupted, the average prices of wood, plastics, and composites doubled between 2008 and 2018. Not only are costs rising, but the environmental implications of the most-used materials are serious. The five most common materials used in residential construction are concrete, steel, wood, stone, and bricks and masonry.
If the concrete industry were a country, it would be one of the top five global CO2 emitters. Concrete is the second most widely-used substance on the planet, after water. The steel industry emits 2.2 billion tons of carbon dioxide annually, more than the emissions released by global shipping and aviation combined. Pound for pound, concrete has about half the carbon footprint of steel, but global demand for concrete means that concrete and steel contribute roughly the same to global emissions. Accounting for all stages of its production, concrete is responsible for between 4% and 8% of the world’s carbon dioxide. In addition to the harmful chemicals and gasses released, concrete requires a huge amount of water—almost one tenth of the world’s industrial water use. This affects water supply for drinking and agriculture, as three quarters of this water consumption takes place in areas affected by drought.
The National Resources Defence Council outlined the importance of decarbonizing cement plants. Cement is an ingredient in concrete, and is hard to replace. While it only makes up about 10% to 15% of a typical mix of concrete, it is responsible for nearly 90% of concrete’s greenhouse gas emissions. Cement production also is responsible for emitting harmful air pollution, and is the third largest source of industrial air pollution.
Mines and quarries take up 0.3% of the land in the US, an area roughly ten times the size of Rhode Island. Out of this, around 60% is used for excavation, while the remaining land is used for disposal of mining waste. Using bricks as siding can increase the embodied carbon footprint—which represents the emissions released during the lifecycle of building materials, including extraction, manufacturing, transport, construction, and disposal—by more than one third. Clay tile is the most carbon intensive roofing material.
Some of the most common materials used in construction have serious implications for our climate. But just the same, some of these materials can be used to harness energy and benefit the environment. Wood products sequester carbon from the atmosphere, acting as carbon sinks. Using stucco as siding requires far less material input than other materials. Linoleum is an all-natural and biodegradable option that can be used in place of more environmentally intensive materials, like vinyl and stone. Cork is harvested from the bark of cork oak trees, but does not require deforestation. After cork is harvested, the bark grows back. It can be harvested every ten years, meaning cork is a much faster renewable than hardwood.
Paying attention to the impact that materials have on the environment across their lifespans is core to the work that CarbonShack Design does. Combining design and technology, the firm builds low-impact homes and empowers homeowners to be stewards of their environment. As buildings become increasingly efficient and renewable energy-based (decreasing their operational carbon footprint), the production of materials used in construction begins to take up a larger proportion of the embodied carbon footprint. CarbonShack works to maximize reclaimed, recycled, and low impact materials in their projects.
As we look to the future in a changing and warming environment, it is crucial to rethink not only how we source materials and build our homes, but to also rethink the kinds of spaces we dwell in and how we live in them.
Written by: Lilly Roth-Shapiro
