The following are excerpts from What Are the Environmental Benefits of High-Density Housing? by Rose Morrison and published in Unsustainable Magazine, July 14, 2022. My comments are indented and italicized.
The American dream conjures images of a house on an acre with a white picket fence. However, there are far too many people for that to be possible without wiping out all our natural resources and destroying habitats.
An acre is 43,560 square feet (sq ft). The average residential lot in the U.S. was 14,000 sq ft in 2020 (and getting smaller every year). My ideal dense single-family home development would have lot sizes of 4,000-5000 sq ft.
High-density housing fits more people into a smaller area by closing the distance between units and building upward…High-density housing most typically takes the form of apartment buildings and condos.
According to the author’s definition, multistory single-family homes on small lots would count as high-density housing. However, she doesn’t acknowledge this possibility. Her article is mostly focused on apartments as an exemplar of high-density housing..
Environmental Benefits of High Density Housing
Increases Energy Efficiency
The close nature of apartment and condo living means less heat loss. These structures are built with efficiency in mind, using better insulation materials to preserve heating and cooling. Also, since warm air rises, apartments near the top of these buildings can often use less heat. Units are much smaller than single-family homes and therefore take much less energy to heat and cool.
Would this be an issue if single-family homes used renewable energy for heating and cooling? Also, apartment units that are “much smaller” than single-family homes are likely to have, on average, fewer occupants as well – and that impacts energy consumption. For example, a study by the University of Minnesota Twin Cities found that the inclusion of a second adult in a household nearly doubled total energy consumption.
A traditional single-family home is exposed to the elements on all four sides, whereas an apartment unit is typically only open on one or two. Due to the extra exposure and difference in building materials, apartments can use much less energy to heat and cool the same amount of space.
Energy efficient building materials can also be used in the construction of single-family homes, eg, insulating concrete forms, prefabricated structural Insulated panels, cool roofing, spray foam insulation, etc.
A study from the late 2000s examined the difference between [apartments and sign-family homes] and found a typical home used around 100 million BTU a year, and an apartment in a complex with two to four units used 60 million. A unit in a building with five or more apartments used 40 million. The savings are significant, and energy efficiency in apartment buildings has only improved since then.
Here’s a summary of the study in question: Apartments in buildings with 5 or more units use less energy than other home types. Note that the data only goes through 2009. Perhaps because the study is so old, it assumes fossil fuels are the sole source of energy for housing and thus leaves unacknowledged the potential of renewable energy to close the emissions gap between apartments and single-family homes. The study also neglects to control for the number of bedrooms or occupants when comparing apartments and single-family homes. Wouldn’t single-family homes, on average, have more bedrooms, occupants, and children than apartments? And wouldn’t that result in greater energy consumption?
Saves Essential Ecosystems
Suburbs grow exponentially as city populations continue to increase, taking up more of the local environment. Animal and plant species already struggling for survival could cease to exist due to this increased expansion. Many animals, like the Florida panther, need large swathes of land to hunt. Others require a very specific natural environment to thrive. Further splitting up their natural habitats disrupts and destroys entire ecosystems.
Single-family homes could be built on already developed lands (infill), such as abandoned industrial parks, and in some less developed areas, such as pasture previously used for cattle grazing. I envision these as dense developments that would not cause the suburbs to grow “exponentially”. The states could impose environmental impact fees on single-family home developments for funding land acquisition projects elsewhere to protect wildlife and create wildlife corridors. These fees need not be exorbitant. For example, in California the average cost of farm and ranch land is around $13,000 and $6,000 per acre, respectively. A per acre cost within that range could then be the basis for environmental impact fees passed on to developers and incorporated into the price of new homes, somewhere between $1,000 - $2,000 each, based on a lot size of 4,000-5,000 sq ft.
Consumes Less Water and Energy in Home Maintenance
Another significant environmental benefit of high-density housing is the reduction of outdoor maintenance required. Families use fossil fuels to power mowers and energy for snow and leaf removal in a traditional home. They spend our dwindling water supply on watering brown lawns and flower beds. However, apartment buildings and condos have much less outdoor maintenance per family since the walkways and entry are communal.
New housing developments in dry areas typically come with landscaping rules that limit water use, e.g., planting only drought-resistant grass, flowers and trees, penalties for excess water use,etc. It’s also important to remember that gardens and trees provide food and shelter for wildlife, among their other virtues. Also, small lawns can be cut with a battery-powered weed wacker, which takes me just 15 minutes every couple weeks.
Reference:
What Are the Environmental Benefits of High-Density Housing? By Rose Morrison/Unsustainable Magazine. July 14, 2022