Walkability/New construction: Difference between revisions
No edit summary |
No edit summary |
||
(2 intermediate revisions by the same user not shown) | |||
Line 1: | Line 1: | ||
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: | |||
<tab name="(see maths)"> | |||
{{dp | {{dp | ||
|<nowiki>building.construction_ghg_by_floor_area</nowiki> | |<nowiki>building.construction_ghg_by_floor_area</nowiki> | ||
|<nowiki>530.43 kg/m^2</nowiki> | |<nowiki>530.43 kg/m^2</nowiki> | ||
|<nowiki>CO2 emissions involved in making a building, per unit of floor area</nowiki> | |<nowiki>CO2 emissions involved in making a building, per unit of floor area</nowiki> | ||
|<nowiki>Includes all materials and construction processes.</nowiki><br /><nowiki> | |<nowiki>Includes all materials and construction processes.</nowiki><br /><small>But probably doesn't include furnishings.</small><br /><nowiki> | ||
</nowiki><br /><nowiki> | </nowiki><br /><nowiki> | ||
Source:</nowiki><br /><nowiki> | Source:</nowiki><br /><nowiki> | ||
Line 59: | Line 66: | ||
|years (average_us_vehicle.fuel_usage * gasoline.ghg_by_energy * usa.registered_vehicles / usa.population) | |years (average_us_vehicle.fuel_usage * gasoline.ghg_by_energy * usa.registered_vehicles / usa.population) | ||
}} | }} | ||
</tab> | |||
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{{x|i.e. an apartment or condo in a multi-unit residential building}} would probably be lower than the old place{{x|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]]. | |||
<!-- TALK: i | <!-- TALK: should i try to find a different case study that deals with per capita (or total emissions and total number of residents) instead of guesstimating floor space per person --> |
Latest revision as of 14:27, 5 November 2023
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.