Image Credit: Alex Wilson
Image Credit: Alex Wilson "Transportation energy intensity" of office buildings—from a 2007 Environmental Building News article; refer to the article for footnotes.
Image Credit: Environmental Building News By building in places with effective traffic calming and pedestrian-friendly street design, such as Annapolis, Maryland (pictured here), vehicle use can be reduced. Photo: Dan Burden.
Image Credit: Dan Burden We also need to advocate for better street design. In Copenhagen, bike lanes are often separated from traffic by a row of parked cars. The sidewalk is on the left. Photo: Alex Wilson.
Image Credit: Alex Wilson
More Energy Solutions
For very good reasons, we focus a great deal of effort in green building on reducing the energy consumption of our structures—after all, these directly account for more than 35% of our energy use and carbon dioxide emissions. But if you factor in the energy used in getting to and from our buildings—usually in single-occupancy cars and pickup trucks—those percentages grow significantly. And while it’s relatively easy to reduce the use of carbon-dioxide-spewing fossil fuels to operate buildings (through efficiency improvements and solar energy, for example), that’s much harder with vehicles, where we rely almost entirely on gasoline and diesel.
If we are to make a significant dent in our fossil fuel consumption, we need to focus attention on where we build, and on ensuring access to public transit and human-powered transit (bicycle paths, bicycle lanes, and walkways).
A few years ago (2007), I dug into the “transportation energy intensity” of buildings for an article in Environmental Building News. I did this for office buildings, but many of the ideas transfer reasonably well to homes. We know how to measure building energy use (often using the metric of Btus per square foot per year); I sought to come up with a parallel metric for the transportation energy associated with buildings.
To do this, I used statistics from the U.S. Census Bureau and U.S. Department of Transportation on commuting distances (12.2 miles each way), how Americans commute to work (76% in single-occupancy vehicles, 11% in two-person carpools, most of the rest via public transit or walking), and average fuel economy of vehicles (21 mpg). To estimate the square footage of office space per employee, I used a U.S. General Services Administration figure of 230 square feet (which I’m told may be significantly lower than in private office buildings). I assumed 235 work days per year.
The bottom line
I found that, based on national averages, the annual commuting energy consumption for a typical office building is about 121,000 Btu/sq. ft. This compares with average office building energy use of 93,000 Btu/sq. ft. In other words, more energy is expended getting people to work than the office buildings themselves use. If, instead of an average office building, we consider one built to the most common energy code (ASHRAE 90.1-2004), this transportation energy use is 2.3 times that of the building energy use.
What this means is that if we want to significantly reduce energy use and carbon emissions, we need to re-examine where we’re putting our houses. Urban infill housing and renovation of older houses in more densely developed neighborhoods is greener than building new houses in suburban and rural areas. If homeowners can walk to the store or a coffee shop, they will be less likely to use their cars all the time.
Building within a quarter- to a half-mile of a transit stop (bus, light rail, or heavy rail) allows easy walking to the stop and use of public transit. It’s no coincidence that in the Washington, DC area property values near METRO stops have continued going up, even while most property values in the region have been dropping the past few years. The same argument applies with bicycle paths—properties close to many bike trails are more in demand and the values are going up.
As they say in the real estate industry: location, location, location!
There are also things we can do in designing or reorganizing homes to facilitate alternatives to driving. Convenient storage of bicycles is one strategy—making it easy to get a bicycle out and use it. If it’s easy, more of us will bike.
At the workplace, providing safe, covered bike storage and shower facilities can help to encourage this alternative to driving. More convenient, premium parking for carpool vehicles may inspire more workers to share rides.
Companies and institutions can also implement a wide range of measures to reduce commuting by single-occupancy vehicle: elimination of free parking, vouchers for public transit (as an employee benefit, or at least using pre-tax income so you’re not paying tax on public transit expense), flexible hours for bicycle commuters to avoid rush hour biking, and other rewards or recognition for avoiding vehicle use.
My top-10 list of green building priorities so far:
#4. Reduce the need for driving
#5. Build smaller and optimize materials use
#6. Ensure durability and reuse existing buildings
#7. Protect and restore the site
#9. Create resilient, climate-adapted buildings
#10. Make it easy for homeowners to be green
In addition to this Energy Solutions blog, Alex writes the weekly blog on BuildingGreen.com Alex’s Cool Product of the Week, which profiles an interesting new green building product each week. You can sign up to receive notices of these blogs by e-mail—enter your e-mail address in the upper right corner of any blog page.
Alex is founder of BuildingGreen, LLC and executive editor of Environmental Building News. To keep up with his latest articles and musings, you can sign up for his Twitter feed.
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34 Comments
WalkScore as a metric
I would like to see more discussion of WalkScore as a metric for transportation efficiency, and a possible category for green building ratings. Sites with high scores go well beyond being 1/4 mile or 1/2 mile of a transit stop. In the 75+ range it becomes feasible to live car-free and depend on public transit, walking and biking. Even for non-car-owners, cars can be available for occasional use from rental agencies and hourly car-share operations. The important step is to begin replacing car trips with alternative ways of getting around. People living in rural areas can't take that idea too seriously (WalkScore = 0).
Alex, thanks for this.
Where we build is perhaps more important than what we build. It's a point too often ignored by the green building community, many of whom have emotional roots in the back to the land, mother earth news attitudes of the 1970's but who cater to a lifestyle dependent on resources which are essentially urban. In my area at least a 'high-performance' home is more likely to be a 2,000 - 4,0000 sf single family residence on a 3-acre lot out in the country than a compact townhome on a transit line within walking distance of schools and groceries, snugly sharing its exterior enclosure with its neighbors.
Talking of schools and groceries, this is not just about commuting to work. I have friends who routinely drive a hundred miles and more a day on itineraries which include school (sometimes multiple schools for multiple kids, these are often 'alternative' schools way out in the sticks), office, school again, after-school programs, grocery shopping and evening commitments in town. And as soon as the kids reach driving age there's another vehicle in the driveway, usually not a Prius, either - more likely a solid old tank "for safety" and for cheap.
Of course there's at least one compelling reason we keep building these rural homes for non-farmers. We're like the guy who was asked why he robbed banks.
"Because that's where the money is."
who decides where we build
As a designer once involved in LEED document administration with every project I went through the exercise of 'lets see how many SS points we got' after the project was well into development.
In graduate school I heard a lecture from someone in one of the Scandinavian countries about the differences in land development practices between here and there. Although I remember few of the specifics this was a very eye opening lecture for me.
Speculative land development I think is a prime cause for where buildings are and the amount of investment put into them (little in order to turn maximize profit). Architecture and contracting is a service industry. We can consult but do not choose where projects are located.
I think work needs to be done to expose the laws that creates the financial infra-structure that creates the conditions for speculative land development in the US. I'm sure some cities have legislation and regulations that incentivize better urban design and reduce reliance on individual ownership of cars.
Architects and builders may contribute to this issue better by getting involved with local politics than by making smaller scale improvements once they are approached with a project which in most cases will already be located.
Where we build
James - excellent, but more to the point, "we" don't know any better...many decades of doing it w/o regard to the larger world.
Fortunately, there are many signs of change in the direction of walkable urbanism. ULI studies clearly show a marked increase in interest in urbanised housing. There's a much greater desire for the urban living experience.
That's good news! There will always be a market for what we used to call country homes, but hopefully we're moving away from that being the dream of the middle class.
http://www.rtastudio.blogspot.com
Response to J Chestnut
From one side of this argument, there should be controls imposed to block sprawl development--no new roads, no subdividing farmland, no big box development along highway corridors. From the other side, that is an anti-business perspective and interferes with job growth. I think the way to "sell" the virtues of car-free (or car-optional) living is through example, including economic opportunities for urban infill. Unplanned low density development works for good old boy builders, while urban sites require more careful design. That empowers good designers when the public (the "market") sees the desirability of a townhouse with less yard and less space but countless hours of highway driving avoided.
An architect or urban designer with a little free time could design examples of sprawl alternatives (specific to local brownfield or infill sites) and publish this work both as marketing and to inspire the public. What I'd like to see is intentional community or co-housing projects planned for good locations and financed by the end users rather than a speculative developer. Multi-unit design addresses the high cost of urban land and gives economy of scale, which has driven upscale condominium and apartment projects in desirable central locations, but these projects are shaped by developer priorities (return on investment). A group of future owners could save themselves that developer's profits and make design decisions to suit their needs more specifically (e.g. three bedroom plans rather than studios).
Thomas, excellent point
I agree that architects, urban designers, and graphic artists could create an inspiring vision of what could be and represent this vision with the excellent rendering skills that are now standard to the industry. I suspect you, like myself, have intentions of this if only we could make the time : )
On the other hand in my locale this actually happens a lot within the design community. We'll get together for a gallery show show off our renderings from the latest competition with spetacular designs that have little basis in cost constraints. We'll pat ourselves on the backs while criticizing everyone else's work among our circles.
I've seen little come out of these exercises in terms of actualizing anything positive in the built environment, but maybe these events are plantings seeds and moving our collective conscientious forward (I'm not really as pessimistic as I may be sounding here.)
More importantly I think we (the design and construction workers) are by and large ignorant of the larger financing and political workings that have the strongest impact and shaping our physical world. (I know I am). Can we expose these? Again I believe there is a huge difference in development laws and financing between the US and Northern Europe (which we often point to as exemplars). Aren't we as designers for the most part just dressing up pigs?
Federal agricultural legislation dictates the agricultural land practices in our country. Sure the demand for organically grown food products is growing but the majority of our agricultural practices remain destructive to the health of our national soils. As long as there is no reform at the federal level the destruction will continue despite gains in organic pratices. And what percentage of citizens even know that there is an Ag Bill and government subsidies that shape agriculture in the US?
I find the design community who often credits itself with 'thinking outside the box' is mistakenly naively optimistic that through design problems can be solved that are not merely design problems. If I had a nickel for every designer I saw try to tackle the phenomenon of homelessness.
Intentional communities? Yes! Co-housing? Yes! Urban infills? Yes! Check out the GBA News "Steps Forward and Backward in Brooklyn"
Politicians
As an Architect and member of my local Planning Commission, I can attest to the obstacle that government often can be to good planning (unless it involves bringing a big employer to town). To get innovative planning on the agenda means getting politicians in office who make good planning their cause celebre, their focus, their reason for getting up in the morning. Those people are usually US, so as J Chestnut says, the solution is to get involved in the political process.
http://www.rtastudio.blogspot.com
Where to build FOR WHOM is the key question
This is a very key topic, I am very glad it is being discussed here. Without restating the many good points made above, it is important that we build FAMILY homes close in to schools and work opportunities, and homes for retired people and empty-nesters farther out. Economics are the reason we do otherwise, the young family with children cannot afford the higher priced real estate offering the shortest commute. This is where a whole new urban model could be adopted: Small town America. We need to get over the idea that we can't have shopping or factories in the middle of residential neighborhoods. With the right model, we could all walk to work, to school, to shop, etc. As a society, we are a long ways off from reaching the ideal community design, we have about 100 years of mistakes to overcome. It would certainly not be green to bulldoze it all and start over, but we do need to begin the process of designing more integrated communities.
Can we all walk to work?
Ted,
"Walking to work" is an attractive dream, but one that is hard to realize. Many unemployed Americans long to move to a new location, in hopes of snagging a job -- any job, one they can reach on foot, by bus, or by horseback if necessary. But they are saddled with a house, and the house is saddled with a mortgage, and no one wants to buy a house these days.
Buying a house makes people less mobile. These days, there is no such thing as a job for life. Everybody changes jobs frequently, whether they want to or not.
Maybe the solution is to become more European: we should all rent. We need more multi-family rental housing in dense neighborhoods.
Response to Martin
In a moderately dense urban area, there's a greater number of potential employers within walking or biking distance. Where I live (Portland, OR) a bicyclist can get around to most of the city, thanks to a combination of density (certainly not extreme), bike lanes and other infrastructure. Anyone who wants to bike to work (and has employment somewhere central) can do so easily enough.
But as you say this lifestyle can be inconsistent with home ownership, because houses or condos in more central, well-connected areas (high WalkScore) are less affordable. To be central enough for living car-free often means renting.
The idea I hope is catching is that there's no real savings to buying a house where property is cheap and then being car dependent, far from any employment, and unable to sell and get out. Plus those affordable suburban homes will burden their owners with high energy bills.
What to do with suburbia?
Here is a link to a presentation titled “Rescuing Suburbia” given by Jeff Vail at the recent 2010 ASPO-USA conference: http://campfire.theoildrum.com/node/7061
I've not yet figured out what I think of this presentation but he does put forth several interesting ideas about possible futures for suburbia that may be relevant to this discussion.
The first is that suburbia represents the backbone of the [American] financial system and is far too large a stranded cost to simply be abandoned in re-urbanization or new urbanization programs.
Another is that supply and transport problems are the low-hanging fruit.
Yet another is that suburbia could become re-configured to become locally self-sufficient. Cheap renewables. Energy efficiency retrofits. Backyard and community permaculture. De-centralization of the means of production through high-tech, small scale manufacturing (3D printing?) allowing suburban garages to become cottage industries. Apparently this is already underway somewhat: http://www.100kgarages.com/
It certainly seems true that if, using existing stock, such a wide spread de-centralization of production could be achieved it would go a long way towards reducing the energy required to achieve transportation and supply. Suburbanites (150 million Americans) could, instead of going to work or going out to get stufff, bring work and stuff to themselves...
Response to Lucas
Lucas,
Two things need to happen if your vision of a rescued suburbia is to occur: people need to become poorer, and zoning laws need to be overturned or abandoned.
Most of these improvements -- using lawns for food production, adding more housing units to increase density -- happen organically in Third World countries. Here, these improvements don't happen because such improvements are illegal and residents are too rich.
When I lived in Armenia, I noticed that the homes in the villages were spaced similarly to homes in a U.S. suburb. But there was no such thing as a lawn. The front yard had apricot trees and grape vines, with vegetables growing under the branches of the trees. The back yard had chickens. And grandma and grandpa lived with their kids, three generations to a family.
Response to Martin
Martin,
I agree that this vision of future suburbia may not be very realistic for many reasons. Not the least of which is the number of forces that are simply out of control in the world today making it almost impossible to plan anything over the long term. To the points you raised:
This may be inevitable anyway. Unless someone suddenly unveils a working, ready to plug in fusion reactor within the next 5 to10 years and we either become master recyclers or are able to put together enough resources to start mining other planets and the astroid belt.
This is of course political theory but in his presentation Mr. Vail suggests that we are already undergoing the beginings of a political transformation from the "nation-state" to the "market-state". Apparently "market-states" are much more open-minded about deregulation when it means an opportunity to lower costs. He says: "For example, intense interest in enforcement of regulations and codes tends to be a preoccupation of the intensive, centralized state. That’s also expensive, and the market-state will likely find that increasingly less important. This is especially true where media fragments, and where open-source networks show potential at some degree of self-policing. Who cares? Well, if you were one of the regulation-aware people in the room who said, “They’ll never let you do that” when I raised the potential of various forms of garage manufacture, this is very significant."
In any case, the future will be extremely challenging. Maybe the future will look a bit like what Cuba looks like now but with high-tech embellishments: http://current.com/news/89990938_the-power-of-community-how-cuba-survived-peak-oil.htm
Your description of Armenian living sounds good too.
city taxes are twice town
I rest my case.
Suburbs
People like the suburbs. That is why they move to them. People like owning houses. That is why they buy them -- "The American Dream." In addition, anyone with kids with any dough-re-mi goes for the best school district possible and screw the commute to work - they'll drive it. As Martin points out, there are no jobs for life in America anymore anyway, so you cannot buy a house with that explicitly in mind... You go for the schools. On top of all of this, I continue to push back on the idea that living in a city is green. If money is a proxy for carbon footprint, the cumulative costs of cities is likely humongous compared to the suburbs: e.g. city taxes are twice town, as noted above. Better, I think, to go to the Village model. BTW, where I live, so few people use the local bus network that I am pretty sure the carbon footprint of the mass transportation is MUCH MORE than if you gave everyone who rode the bus a car. In fact, I would also like to see the carbon footprint always calculated for mass transit (see discussion of "cities" above). It's only when we get this data in front of us that we can really know what we are talking about. Sorry for the rant. I've had a lot of coffee.
Cites are the worst example of progress!!!!!
Thank you Pam for posting. I can't believe you are the only person so far that sees what I see. Plain and simple economics 101. Cites cost 2-3 times more to operate than towns. Exactly the opposite of these urban planning ideas being dreamed up for the USA. Dream up a plan that has half the tax rate of my town and I will jump on board pronto.
A sort of related aside.....
We need to go back to vollunteers running governments. with no pay, no health care benefits and no retirement benefits, Same for teachers almost, Teachers should teach for 5-10 years with wages only, no retirement, health care paid for by them, and then move on into the private sector. Upon retirement, they can come back to teaching as vollunteers doing if for the love of teaching, not for the easy early retirement that todays teacher get. For some reason in the last decades we thought money grew on trees and came from some unlimited money store! My point about taxes is really in your face the day you realize that sure, I can build a hers 0 rated home that has no annual costs for energy.. but then... we still have huge annual costs for property taxes that only go up up and up! So... then one needs to go offshore in a bay living in a net zero house boat to drop that $15,000 dollar annual bill the the king.
Green building is a tiny tingy fraction of what is needed to change course in this country.
And moving us all to twice as expensive cities living in cubes called condos is not for me. But I'll take the bike, thank you. (I do have a bike and do ride into my town, 1/2 mile just haven't tried pulling a log for a nice natural log home by it yet)
City taxes versus urban taxes
It's simply untrue to generalize about property taxes. There are plenty of cities with lower property taxes on a $250,000 home than the same home in some rural areas. Property taxes vary for a wide variety of reasons, including whether or not the state has an income or sales tax.
In almost all cases, the following costs are likely to be lower in a city: space heating, space cooling, and transportation.
martin.... wake up..... read my post closer.
Best case habitats (living quarters) are net zero or net positive. The remaining huge cost is property tax in most of the Usa. If we telecomute and bike and walk, then...
You are 99.99% wrong my friend and fellow god.
Love,
A non mouse
Pam,
Certainly it is true
Pam,
Certainly it is true that a large number of Americans choose suburbia and spend hours driving every day. They don't use public transit because low density areas make that terribly inconvenient and inefficient. Many of the same people live in extravagantly scaled homes that consume a great deal of energy. This is exactly the issue we must address. The USA has 5% of the world's people. The other 95% use much less than we do. The situation is unsustainable, and the worst offenders are suburban Americans. It's time to stop making excuses.
Suburbanites use far more energy than urban dwellers, both for transportation and buildings. Consuming more costs more. Using less does not require greater affluence, the opposite is true. Affluence makes it possible to consume more resources. Most importantly, there's no evidence that the world's most consumptive people are also the happiest. You can make changes to address fossil fuel addiction without endless hardship. Your kids' schools are not the only issue to consider, when they will be living with consequences of your choices.
Thomas J....
Cities around me have taxes that are two or more times higher than my town. I don't consider where I live to be suburbia. Most of the homes in towns in upstate NY, one can walk, and bike if one chooses to. There are very few McMansions. With zoning changes more of us could work from home. Leaders of the past and present are clueless to how to promote sustainable communities. Moving us all to cites is abhorrent to me and most people who live not in such density. You can post what you did all you want and none of us are going to live in your idea of a better future.
You are part of masses of new greenies that have no clue. of uninteded consequences and also what important part costs has to do with personal incentives to live differently than we all presently do.
Debate this with me if you like.... but address my tax issue first.
a non mouse & god
Density or not
Whether you end up moving to a denser urban area or deep into a forest somewhere, the real issue is the resources you consume. Look at the comparison between American energy consumption vs. the other 95% of the world's people and ask, is this impossible to address because of something to do with taxes? It's about choices, and not one simple solution. Living on a farm can be highly resource efficient but not if it means endless hours of driving. I would not propose forcing anyone to leave towns or suburbs to move downtown, but I would like to see how exactly the most energy dependent people (suburbanites) can manage a giant reduction in their consumption (80-90%) in coming decades. I don't think it's reasonable or ethical to assume that some amazing new clean energy resource will soon emerge that will avoid this necessity.
Response to Pam
Pam,
It isn't really a good proxy.
This is incorrect. Half the energy used by a vehicle throughout it's lifecycle (and perhaps half it's lifecycle carbon footprint) happens during it's manufacture. This is one reason why the process of commuting is ultimately doomed. Not even a total transition to electric vehicles can change this.
I have to echo T.J. statement:
Response to AJ
Oddly enough I agree with you in that I don't believe it is very realistic to abandon the suburbs in favor of new or re-urbaniztion programs.
The reason I don't believe it is a very realistic idea is that the material investment we have made in suburbia is far too great to just abandon.
I think it would be better to try for something like what I wrote in my post above - salvage what we can of suburbia and reduce it's energy consumption on the order of 90%.
I think you are off base in using a simple present day factor like local property tax rates as the backbone of your argument. Government systems change. Laws change. Taxes change. And ulitmately, cash money is a man-made device whose present-day value is not guaranteed into the future.
People have long gotten used to the idea that money makes the world go round but in reality, energy is what makes the world go round. No energy, no economy, no money. Period.
So, while I would like to believe that there is time for people to be financialy incetivized into any type of positive lifestyle change, I don't think our future outlook for energy resources will allow the time for this to happen on the scale that will be neccesary.
Driven to Despair
On this subject, here's an interesting little film (23 min) from the PBS series Blueprint America: http://video.pbs.org/video/1115444774/
For crying out loud,
For crying out loud, suggesting there is an environmental effort to make anyone move to soviet style apartment blocks cities is absurd and distracting. The real issue many of us are struggling is that right now it is illegal to build the types of houses many people desperately want: townhouses in walkable neighborhoods with public transportation and jobs nearby.
Again: the zoning changes of the 1960s and 1970s made building these types of neighborhoods practically impossible, which is why they are currently so expensive to live in. Pick any urban area you can find, and the inner ring suburbs built from the 1920s to 1940s are the most expensive, desirable and have the best public transportation, but you can't legally replicate them today. This is a clear sign of a market failure.
It's like Yogi Berra supposedly said, no one goes there anymore, it's too popular.
We're not talking about Manhattan skyscrapers vs. The Suburban American Dream, we're talking about allowing people to build more of what many people have proven to want when they are allowed to vote with their pocketbook. Families with young children might always prefer the classic suburb, but most people outside that narrow age band would greatly prefer the option living closer to food, entertainment and other people.
And just about every study I've seen has shown conclusively that living in cities of all kinds dramatically lowers energy intensity. The current US suburban housing model is an environmental disaster, we need to allow other options to be built so we can truly see how people want to live when given the choice.
Response to Jesse
Jesse,
It is interesting to hear your frustration about zoning against space efficient housing types. Here in the other Portland, zoning has encouraged townhouses, duplexes and "skinny" houses. If you search the MLS and sort by price, many of the least expensive listings are rowhouses in non-premium neighborhoods. They are cheap partly because developers save on the land investment and on roads and other infrastructure. A selling point for attached but not vertically stacked housing is avoiding the HOA dues of a condominium (saving cost for homeowners), and building under residential codes rather than commercial. Note also that some of the most expensive housing is also townhouses, but in the most desirable central areas. Price per square foot goes way up as WalkScore approaches 100.
For a city to develop this way requires vision on the part of planners and commissioners, applying higher density zoning to areas along transit corridors. In many cases isolated vacant lots get zoned multi-family even when surrounded by detached homes. Sometimes when up-zoning adds value to land, this creates pressure to demolish livable but modest homes and replace them with 4-plexes. That did happen during the housing boom. The Urban Growth Boundary also makes all the included land more expensive, but that's an incentive not to waste space on parking lots and inefficient suburban use patterns.
Tax flight / driving
Note also this regional example: In pursuit of lower taxes or housing prices, some people commute across the state line and live in SE Washington where there is no UGB and plenty of suburbia. The downside for them is traffic jams, wasted time (day after day) and fuel costs. Most people I've talked to who live this way readily admit it's a heavy tradeoff and they hope to eventually either change jobs or move closer to work. These folks have colleagues who happily bike to work and rarely experience traffic jams, so they get reminded of the non-necessity of car-centered living.
Response to Jesse
Who suggested this?
I agree with you that zoning laws are an obstacle to better living. However, listen to that family in the video that Thomas linked above. Triple digit oil and $4/gallon gasoline turned their lives upside down. It's unlikely that they will be "voting with their pocketbook" anytime soon. They're already trapped paying double what their house is worth.
Something like 150 million Americans live in "suburbia". When gas gets to $4/gallon again next year, how many of those suburbanites will be able to "vote with their pocketbooks" to get out of the suburbs? Probably not many.
I urge you to read this case study on urban energy use by David Fridley of the LBNL:
http://www.theoildrum.com/node/6842
A salient quote from the study:
"Analyzing the current energy consumption of a city alone can lead to conclusions that urban areas, particularly dense urban areas, are relatively efficient, largely because per-capita current energy consumption is lower than in dispersed urban or suburban arrangements. This is indeed often the case. But what is not measured as part of the energy impact of urban areas is the built space itself—the streets, pavement, buildings, utilities, tunnels, etc.—that are required to maintain such a dense arrangement of humans, nor does it take into account the energy used to manufacture, transport, and sell the array of consumption goods and services that urban residents purchase."
In other words, if you look strictly at "operational" energy consumption then yes, urban centres are more efficient than other arrangements. Take into account the infrastructure that is obviously critical to supporting the city which depends on it and things become more ambiguous.
I know my opinions are gloomy but there seems to be a real lack in most people's understanding of just how tight our near future energy outlooks really are. The economy's speed limit is never going to be what it was when it had cheap energy and things are going to change because of it. We're getting to the point (if not already past it) of requiring a full-scale WW2 style mobilization of national will and resources to overcome problems which in hindsight will appear as the biggest market failures of all time.
From a building perspective, new stock of advanced "green" homes is almost certainly not the answer. Tackling the problem from the perspective of building new is too energy and material intensive. Existing infrastructure is already being let go - new infrastrucutre projects will be difficult or impossible. I'm guessing, but I'll bet the best results will be had by reconfiguring what we already have with deep-energy retrofits and cheap renewables. Leadership in establishing powerful incentives in this regard would be nice. Additionally, if people should stay in the homes they already have, then people need to be given alternatives to commuting. Leadership in establishing electric mass transit and in community re-habilitation would also be nice.
I'm not trying to be a pompous ass here but we got a rock on one side and a hard place on the other and we gotta get on with the choosing. The clock is ticking loudly.
Two good posts Lucas and Jesse...
Not bad, I am finally seeing posts after I post that are interesting points and counter points to mine. Thank you all for getting into it a bit. If we all worldwide can start to debate what this green idea is and how soon we need to get there... we will make it just in time like we have so many times since the beginning of time.
a non green mouse ...
that may soon be 2% green on the way to being a real practicing 100% greenie
Extra energy use in cities
These could be factors adding to energy use in cities: (1) heavy concrete and steel structures for high-rise construction; (2) elevators and air conditioned lobbies and corridors in tall buildings; (3) artificial lighting needed when floor plates are large and daylight doesn't reach far enough; (4) subway systems; and (5) structured parking. However I don't see how other infrastructure is less efficient--streets for example serve many more users per mile (less paved area per person). It's not as if pavement is unique to cities, and same for water, wastewater and other services. Again on the topic of this blog post, there's great value in short distances between different destinations around town.
The list above suggests that beyond a certain level of density there are added material demands (and cost, for the same reason). But none of this diminishes the efficiency of townhouses (single family attached) as a building type, in comparison to detached housing. I think there's a sweet spot for density, and it's short of a high-rise but beyond detached single family. It should ideally allow residents some space for a garden or a hen house, even if that's on the roof.
Thomas... you have a point for densely lived areas... but
Where I live... we live on much less $$$ green and will never have a need to attach our homes together. Passive House, net zero and telecommuting along with walking, and biking all works here with out building one McMansion or one townhouse.
Of course I do not live in the Washington to Boston corridor where your ideas do make much more sense.
a non mouse
Response to Thomas
I agree and I don't believe that it is. However, the model used in the case study I cited does indicate that the statement "living in cities of all kinds dramatically lowers energy intensity" has not been proven conclusively. As I said it's ambiguous.
One point that is made clear (and which I think is the critical issue here) is that by virtue of it's scale, the creation of urban infrastructure has an enormous (and unsustainable) energy footprint in absolute terms. This footprint absolutely needs to be considered as part of the spaces we build to live and work in. Currently it is largely ignored as an externality.
With respect to suburban infrastructure, there is also (in absolute terms) an extremely large energy footprint to consider. For better or worse we have already made a huge investment of energy and material in suburban infrastructure. For better or worse we are committed to those investments since they cannot be undone. If we allow record high fuel prices to drive everyone out of suburbia, that investment becomes lost and cannot be replaced for, or re-used in, the creation of new environments. I don't think we can afford to simply let all that stuff go.
I agree with you here again too. I just don't believe that we have to build new or expand urban landscapes to find that sweet spot. I also think it is critical that more people start thinking about how to find that sweet spot in existing suburbs. There are ways that the suburbs could be re-engineered to be self sufficient enough that a 90% reduction in the energy used for transportation could be achieved. Getting there requires what most people currently consider radical changes to the way we live (like raising chickens in your back yard). But hey, that's just a perspective.
An aside
I started a thread in the Q&A a while back after I had first read that LBNL study:
https://www.greenbuildingadvisor.com/community/forum/general-questions/18002/relative-importance-embodied-energy
This problem of the externalization of certain energy realities (ie: creation and maintenance of infrastructure) are worrisome and is worthy of some attention itself.
Response to Lucas / Thomas
What is our density sweet spot? High density buildings have advantages in energy usage and productivity if utilized properly. High density urban centers offer economies of scale with regard to public transit and infrastructure.
"I also think it is critical that more people start thinking about how to find that sweet spot in existing suburbs. There are ways that the suburbs could be re-engineered to be self sufficient enough that a 90% reduction in the energy used for transportation could be achieved."
I agree here. I think multi-use developments or so-called "urbanist" neighborhoods can achieve many of these goals in a reasonably efficient manner. As an example, I live in such a neighborhood in Chapel Hill, NC where a central market (restaurants, grocery, services, concert area, etc.) is surrounded by apartments, townhomes and homes. On the periphery are walking trails, dog parks, athletic fields, playgrounds, an elementary school and access to the (free) local bus system. The community is vibrant and draws others from outside the area and the university. Personally, I think an emphasis on community has created a relatively efficient and moderately dense work/play environment.
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