Walkability/New construction
If walkability is achieved by building brand-new neighborhoods, how long would it take to "break even" considering the carbon emissions of the construction & materials?
Simplified model
- consider the carbon footprint of making a new building, per person living there.
- assume a full extreme lifestyle change: people go from "USA average" amount of driving, to zero driving.
In such a case, it would take about 7-8 years to pay itself off:
building.construction_ghg_by_floor_area
530.43 kg/m^2
CO2 emissions involved in making a building, per unit of floor area
Includes all materials and construction processes.
But probably doesn't include furnishings.
Source:
Case Study on Carbon Footprint Life-Cycle Assessment for Construction Delivery Stage in China
by Xiaojuan Li, Chen Wang, Mukhtar A. Kassem, Shu-Yi Wu, and Tai-Bing Wei
https://www.mdpi.com/2071-1050/14/9/5180
Sustainability 2022, 14(9), 5180; https://doi.org/10.3390/su14095180
Quote: "...the area carbon-emission intensity is between 400 and 800 kgCO2/m^2, and the average area carbon emission of the building is 647.99 kgCO2/m^2 compared to other research results for emissions around 412.87 kgCO2/m^2"
So I decided to take the midpoint between both figures.
But probably doesn't include furnishings.
Source:
Case Study on Carbon Footprint Life-Cycle Assessment for Construction Delivery Stage in China
by Xiaojuan Li, Chen Wang, Mukhtar A. Kassem, Shu-Yi Wu, and Tai-Bing Wei
https://www.mdpi.com/2071-1050/14/9/5180
Sustainability 2022, 14(9), 5180; https://doi.org/10.3390/su14095180
Quote: "...the area carbon-emission intensity is between 400 and 800 kgCO2/m^2, and the average area carbon emission of the building is 647.99 kgCO2/m^2 compared to other research results for emissions around 412.87 kgCO2/m^2"
So I decided to take the midpoint between both figures.
gasoline.ghg_by_energy
71.30 kg / million btu
CO2 emissions of burning gasoline
https://www.eia.gov/environment/emissions/co2_vol_mass.php
average_us_vehicle.fuel_usage
489 gallons gasoline/year
The average American vehicle uses this much gasoline (measured in energy units)
Top Numbers Driving America's Gasoline Demand
https://www.api.org/news-policy-and-issues/blog/2022/05/26/top-numbers-driving-americas-gasoline-demand
Note: Since the statistic is mentioned specifically in relation to gasoline, we can '''probably''' assume that it excludes diesel-powered vehicles such as semi trucks. But the website doesn't specify that, so it's anyone's guess.
https://www.api.org/news-policy-and-issues/blog/2022/05/26/top-numbers-driving-americas-gasoline-demand
Note: Since the statistic is mentioned specifically in relation to gasoline, we can '''probably''' assume that it excludes diesel-powered vehicles such as semi trucks. But the website doesn't specify that, so it's anyone's guess.
usa.registered_vehicles
275.9 million
Number of registered vehicles in the USA
Top Numbers Driving America's Gasoline Demand
https://www.api.org/news-policy-and-issues/blog/2022/05/26/top-numbers-driving-americas-gasoline-demand
https://www.api.org/news-policy-and-issues/blog/2022/05/26/top-numbers-driving-americas-gasoline-demand
usa.population
334416477 people
Number of people living in the USA
United States Population (Live) - Worldometer
www.worldometers.info › world-population › us-population
Last updated April 7 2022
www.worldometers.info › world-population › us-population
Last updated April 7 2022
home_space
400 square(feet) per person
private_fraction_of_building
70%
Percent of the building's floorspace that is private living space
The rest is hallways, stairwells, and common rooms.
(calculation loading)
The real-life figure might be higher, because...
- can't really expect a full change to zero driving, just a lot less than before
- the calculation didn't include interior furnishings of the building, as far as I know
The real-life figure might be lower, because...
- the footprint of heating the new place
(...)( i.e. an apartment or condo in a multi-unit residential building ) would probably be lower than the old place (...)( i.e. a single-detached suburban home ) - less construction in other ways (especially road maintenance)
In any case, the carbon payoff of new construction could be worth it if there's no better option for Walkability/Existing housing.