These principles are the ethical drivers that have informed my personal interest in ADUs. Making these two personal lifestyle choices will very likely decrease one's environmental impact significantly (without much concerted effort for the individual to be more 'green' or 'less consumptive').
My conclusions are based on findings that closely correlate personal energy and consumption impacts to residential locational and housing size.What follows in this post are selected infographics and text that help explain these recommendations.
For US residents that generally believe in climate change trends, and therefor understand the importance of reducing individual energy consumption, it is also important to understand that we owe it to the rest of the world to reduce our individual carbon impact. I am suggesting here, that living compactly is the easiest and probably the most substantial way that most of us can reduce our individual carbon, energy, and BTU footprint.
|Tons of carbon dioxide emitted per capita in the US and globally|
I'll clarify my opening prescription- living in under 400 sq ft. is an arbitrary residential square foot benchmark, not a numeric prescription. My intention is to convey that the smaller the residential footprint per person, the less the environmental impact. I've provided background data about living in smaller spaces in an earlier post. This post will focus more on residential location choices.
You can find more wonderful infographics that originate from the same report in my earlier post entitled Common Forms of Living Smaller. You can also watch a 1.5 hour Oregon DEQ presentation about the Residential Buildings: An Evaluation of Waste Prevention Practices Using Lifecycle Analysis report on EPA's website.
|This quantitative analysis of residential construction types shows that in terms of residential housing types, housing size is the most significant variable in terms of ecosystem quality, human health, and energy consumption.|
Urban density is an important factor to sustaining a vibrant urban, walkable community. The urban density in US cities is an average of 2,900 people/mile. Portland's average urban density is 3,507 people/sq mile. By comparison, New York city is 23,705 people/sq mile and Pheonix is 2,342 people/sq mile (based on 1990 Census data). My neighborhood has a density of 4,241 persons/sq mile, or 14 people per acre.
When a sufficient level of residential density is overlaid other critical aspects of urbanity, such as mixed zoning districts that include employment opportunities, readily accessible park networks, a variety of housing and transportation options, a region will significantly reduce its energy demand per capita.
Oregon had the foresight to create an urban growth boundary in 1977. This 30 year old policy, has resulted in a range of benefits that are becoming increasingly evident to urban planners and residents alike. The proactive, multi-jurisdicational, planning modality, appropriately reflects and manages the region's transportation, housing, and employment demands.
Portland's viable transportation alternatives and vibrant neighborhoods are a testament to the success of the urban growth boundary. A range of other unique urban planning policies and natural assets have helped make Portland walkable and community focused. While most, if not every, city in the US has seen a growth in total vehicle miles traveled from 1996-2008, averaging growth of 9% over that period, Portland's total vehicle miles traveled from 1996-2008 has dropped by 12%.
The following screen shots were taken from a presentation by Peter Calthorpe, Calthorpe Associates.
Contrary to a popular assumption that transit is the most viable alternative to driving, using the following graphic, Peter Calthorpe explains that transit should be conceived as a third tier support mechanism for walking and biking. In the western, industrialized cities in Europe, transit is not the dominant form of transportation, nor is driving. The dominant form of transportation is actually walking and biking.
Cities have to focus first on making places that are walkable. Transit should be perceived as a way of extending the walk/bike domain. To accomplish this end, cities need to provide more mixed use, high density housing choices in a range of prices within given neighborhoods.
Hidden Personal Costs of Living in Sprawl
However, even if no active policy choices are made to adopt and adapt cities for future livability, the market will nonetheless steer builders, architects, developers, in this direction. The demand for exurban, large lot housing is going to slowly decline over this generation, and large lot exurban properties will be increasingly labeled as a liability.
Here's a couple personas (Dave and Karen) that exemplify common lifestyle differences between Dave, a resident in a single family detached house in a "conventional suburban development", compared to a Karen, who lives in a multi-family building in a "transit oriented development", and the respective amount of energy (BTUs) that they use as a result of their transportation choices.
This data is based on a report called "Location Efficiency and Housing Type - Boiling it Down to BTUs," that was funded by the US EPA. This presentation from which these graphics were extracted is available on this HousingPolicy.org website.
Market Trends Towards Urban Revitalization
Solely allowing the free market to guide urbanization trends means that the urbanism trend will not be coordinated and managed as well as it could be, and will cause financial hardship for many homeowners and municipal governments.
|Graphic from a report called Growing Cooler|
Embracing Infill Housing Programs
ADU's are one of many programs that cities should actively adopt in order to to increase housing options in areas where there is sufficient housing demand. Currently, many communities do not allow ADUs. Moving forward, urban communities that are seeking to actively embrace an environmental ethic should seek to:
- Expand the range of allowable housing options and areas in which they may be built
- Revise policies that make these housing types impractical
- Consider ways to reduce the reliance on variances and expand "as of right" development opportunities
Recommendations from HousingPolicy.org
In the US, I think that we owe it to the rest of the world to reduce our energy consumption footprint. In the US, living compactly is a contrarian choice, but the dominant habitat that we observe and experience in the US when driving from one place to another is neither healthy for us nor sustainable.
But, individuals can make an active decision to live in a smaller space at home, to live more compactly within their community, and enjoy the financial and lifestyle freedom that these choices provide. Indeed, there are social and health benefits to living smaller, but perhaps the most compelling reason is the decreased transportation and decreased housing costs associated with this passively virtuous choice.