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It appears to me that a sustainable city should be described first by the interactions that take place within, and a description of the product was not enough, it should include a description of the flow and services. I need to develop dynamic principles that give an account of the interactions within the city. The reading of the City Reader, and the description of the sustainable city as ‘an organic whole’ was a great source of inspiration for me. Indeed, the idea is not to develop the inputs, outputs and the products of a city, but rather to connect them in order to sum them up into same principles. Sustainable cities are analogous to nature in the way they function. This description of an urban metabolism helped me to choose my pattern. I have been inspired by the core ecological concepts described in Ecoliteracy to define five principles of a sustainable city: networks, cycles, flows, dynamic development and nested services.
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Charles HAZET 2014 SPRING TERM -‐ Greening the City Final essay-‐ 18th May 2014
GREEN and SUSTAINABLE CITY PRINCIPLES
Introduction Looking back to what I wrote eight weeks ago, I can notice how my views have changed. I had developed five principles at that time: outdoor living and public space, integrating nature to the city, large scale of public transit offering, high-‐performance building and design and public participation. I still agree with those ideas, yet I can now describe a green or sustainable city from a broader point of view. I have tried to find a pattern that help me describe such a city not by describing the products-‐ i.e building and public space, but by describing the underlying idea. Indeed, it appears to me that a sustainable city should be described first by the interactions that take place within, and a description of the product was not enough, it should include a description of the flow and services. I need to develop dynamic principles that give an account of the interactions within the city. The reading of the City Reader (1), and the description of the sustainable city as ‘an organic whole’1 was a great source of inspiration for me. Indeed, the idea is not to develop the inputs, outputs and the products of a city, but rather to connect them in order to sum them up into same principles. According to (1), green cities are analogous to nature in the way they function. This description of an urban metabolism helped me to choose my pattern. I have been inspired by the core ecological concepts described in (2) Ecoliteracy: networks, cycles, flows, dynamic development and nested services. Looking back to the class discussions, I was able to adapt these principles to the green city.
1st principle: developing the city as an optimized and balanced network to foster connectivity
• Transportation
The first idea that comes to mind when dealing with connectivity between the communities is the transportation networks. It includes roads, but also public transit, bicycles, and pedestrian streets. I have learned some tool that can be implemented in the workforce to change the current situation. For example, a recipe for a successful transit service network is to concentrate the population around a transit stop. The table2 of transit modes related to residential density in (5) enlightens the tight relationship between density and transit modes. People who live near transit stations have about half as many cars as their regional neighbors. It is interesting to notice that it is necessary to consider the fact that people may use a couple of transit modes. The network of parking should be assessed and open the way to new standards which require less land use, such as sharing parking space between uses. Car-‐free housing can be used as a tool when a car is not necessarly needed by dwellers. It could be an incentive step to encourage dwellers to drop their car. Another solution is to develop a
1 (1) Page 6 2 Table 5-‐3
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car-‐sharing network, such as PhillyCarShare in Philadelphia, Pennsylvania or Zipcar in Boston. Another paramount point is to integrate a network of walkable streets. A good example of that challenge is illustrated by ‘Visit the 3.5 mile Spicket River Greenway’ video3. Tools are given in (5) to achieve this goal, for instance the fact that the network should be 1500 feet with a maximum uninterrupted block face of ideally 450 feet, with streets at intervals no greater than 600 feet apart along any one single stretch. A network of complete streets should be built, that are designed to accommodate all travel modes. (1) also underlines the importance of supportive networks of associations dealing with sustainabiity.
Parking, bus station and trolley station at the same place in Bordeaux (France) 4 to encourage dropping the car to take public transit. Urban networks are connected by such node points. Again, from the first week, my idea
of the green city has evolved, and now includes all kind of transportation, beyond public transit, and the fact that they should be interconnected.
• Complete and compact neighborhood The idea is also that a community should be connected easily to every compatible land uses (3) and services. To achieve that goal, the city should also include a balance and compact network of services, housing and jobs. As stated in (4), the growth in driving, responsible for a large part of the increase in CO2 emissions, is due to the current urban development which consist in building housing far from workplaces, inacessible schools and isolated shopping destinations. The solution, described in (3) and (5), is to develop a mix in uses. Every residential neighborhood should have its corner store providing the daily needs, as well as a school and work centres. Another tool that can be readily employed in the workforce is to abide by the rule of ‘one-‐quarter mile catchment aeras’ for each destination that helps getting every daily need at a walkable distance. Another tool to reach completeness is the network of parks, as described in (6) that should be at a walkable distance from every destination to make the city a livable place and community, as it becomes ‘aesthetically inspirational and emotionally uplifting’(1).
• Challenge to bring the principle to fruition As stated in (5), a huge challenge is to tackle the people fear towards connectivity. This could be handled through explaining the benefit that can be taken from the change, using tools such as charette to share the design of the aera with the public. Another challenge is that developing networks requires a large scale approach, in order to anticipate all the necessary step to fulfill. Building a wide diagnosis and planning the necessary work must be done at a city scale. Some examples are given in (6). For instance, the climate change action plan : Progress Report conducted by the City of 3 http://www.groundworklawrence.org/gwl_video 4 http://www.sudouest.fr/2013/10/12/grand-‐bordeaux-‐les-‐parcs-‐relais-‐satures-‐1196992-‐2780.php
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Seattle in 2007. It introduces a development of green neighborhoods, pedestrian access and transit to implement the shift away from automobile to transit, bicycles and walking. Another good example was given by Jessica Broderick on the forum of the class – plaNYC20305 that develops all the different aspects mentioned above and the practical tools implemented to achieve them.
2nd principle: Optimize the use of resources in continual cycles within the city This principle leans on the fact that the exchanges of ressources should be
maximized within the city. An example is the production of local-‐grown vegetable in community gardens or orchards, or on rooftop (5). It is a good opportunity to involve the community into a common project. Local farmers’ markets can also make a direct link between local ressources and people living in the city. A good example of such initiative is the New Seasons Market in Portland6. Another example of continual cycle leading towards a sustainable city is producing
energy onsite, thanks to renewable ressources as wind or sunlight, which are following cycles. This could be managed through appropriate zoning codes that enable the installation of compact wind turbines or solar panels like in the BedZED South London project that achieve zero net carbon emissions through the use of alternative energy such as solar panels. A federal research lab stated in (8) underlines that a microturbine with six-‐foot blades on a 50-‐
foot pole could supply all of the energy for two homes. Another cornerstone of building a sustainable city through restoring continual cycles within the city is the run-‐off management in order to restore the natural water cycle. The idea is to facilitate infiltration through means described in (5) – i.e porous paving, deep-‐rooted urban landscape and rainfall cisterns as developed in Green City, Clean Waters Review of Philadelphia. The idea is to limit the amount of water that is colleted by sewer and that provokes huge damage on the river banks by erosion, let alone pollution. The use of natural water cycle for the irrigation of gardens deters people from pumping from ground-‐water sheets. Material reuse is also a good way to put into practice that cycle principle, it was one of the benchmark of High Point Seattle (Washington United States) stated in (5), and it was also the case in New Orleans after hurricane Katrina left tons of wreck behind7. From the first week, my view has changed a lot, as I had not thought of any of these idea before. At that time, I had underlined a principle of ‘integrating nature into the city’, but it was quite different and was more about green open spaces. This idea is
5 http://www.nyc.gov/html/planyc2030/html/theplan/the-‐plan.shtml 6 http://www.newseasonsmarket.com/ 7 http://www2.buildinggreen.com.proxy.the-‐bac.edu/article/bold-‐plan-‐new-‐orleans?ip_login_no_cache=3ca91b3b7a3982447a10102281fc1087
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larger, it implies that the city should strive to achieve a circular rater than a linear metabolism, beyond the input-‐>output pattern.
• Challenges to bring the principle to fruition Some chalenges arise when thinking about implementing this principle. The first one is a NIMBY reaction against wind turbine or solar panels, arguing that it will damage the landscape. This case is very common in Europe in particular, where NIMBYs sue almost every wind power plant in court8. To tackle this challenge, every potential impact should be anticipated in order to find solutions. An example, given by the English Heritage, is to install the roof solar collector on the roff’s reat slop so it is not visible from a public highway9. The same organisation has published a Micro Wind Generation and Traditional Buildings guide10.
A traditional house with a pole-‐mounted turbine (from Micro Wind Generation and Traditional Buildings, English Heritage)
Another challenge is to tackle the high price of photovoltaic panel. Even with the saving on energy bills, dwellers may be reluctant to invest on the long-‐term. A solution may be to implement financial incentive to offset that reaction. This is the case in Britain with the Governement’s Green Deal11 that enables to pay the energy-‐saving work through levy on the bill. It is also the case in France, where half of the price of the installation can be taken off from the income tax during five years. Another incentive, as stated in Green City, Clean Waters Review of Philadelphia, is to install renewable energy first on public buildings, paving the way for neighborhood dwellers to envy it and become aware of that possibility for their own house. I believe another challenge for that principle is to find available places within the city to develop community gardens. This should be done thanks to a Land Bank, as described in (8). These governmental or public entities would have the means to acquire abandoned lands in the city, and convert it into community gardens. Another challenge to develop local food growing is the competition of traditional supermarkets. These hypermarkets rely on existing network on an input/output basis. They are well organized and productive, and can therefore offer cheaper goods coming from hundreds of kilometres. This challenge should be tackled through appropriate zoning code to deter superstore to settle within the city. It should also be tackled by associating the public and communicate the healthy model of buying locally grown vegetables and fruits. 8 file://localhost/Lyman, Francesca, "From Vacant to Verdant/ Rethinking the Shrinking City", Parks & Recreation, July 2008. pp. 36-‐41 9 http://www.english-‐heritage.org.uk/your-‐home/saving-‐energy/generating-‐energy/ 10 http://www.english-‐heritage.org.uk/publications/micro-‐wind-‐generation-‐and-‐traditional-‐buildings/ 11 http://www.english-‐heritage.org.uk/your-‐home/saving-‐energy/green-‐deal/
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3rd principle: optimizing the energy flow and ressource flow required This principle can be done first at the construction scale of the building.
The ideal would be to reach a passive house that demands the minimum of energy flows. Designers and planners can manage to achieve energy efficiency, in terms of thermal envelope efficiency, HVAC system efficiency, whole building electricity and lightning, and building size. Designing the building envelope (i.e, the way of construction of wall, roof and windows) is up to the designers and architects. They can incorporate natural heating, cooling, ventilation and daylighting strategy. Another actions is to promote rainwater harvesting that can be useful for landscape watering and indoor non-‐potable uses (flushing, washing). Water-‐efficient landscapes can also be designed to reduce irrigation needs and potable water consumption. Residential water conservation kits can help reduce the flow of waste. As far as electricity is concerned, designers can put up LED lighting. Assessing material before use can help reduce the flow of waste and energy consumption. Designers should be wary of the product life-‐cycle, the resource acquisition, the manufacturing, the transporting, the energy necessary for installing, the performance, and last but not least the end of use options. A good solution to implement this principle is often the retrofitting of existing building, as stated in the Greenest Building – quantifying the environmental value of building reuse (10), demonstrating that reusing an existing bulding and upgrading it to be as efficient as possible is almost always the best choice regardless of building type in climate, provided it is done with careful material selection and efficient design strategies. By reusing an existing structure within a site, the energy required to create these spaces is lessened, as is the material waste that comes from destroying old sites and rebuilding using new materials.
Example of adaptive reuse of an existing building from http://preservationinaction.blogspot.fr/2012/07/adaptive-‐re-‐use-‐repurposing-‐existing.html
The importance of building orientation and massing is a tool to optimize energy efficiency. In the workforce, tools are given in (5) i.e reducing surface-‐to-‐volume ratio as much as possible, and reducing south-‐facing glass that receives direct sunlight.
Planners can also have a great role at neighborhood scale, by developping a district energy system, like the co-‐generation heating system. This kind of system can help reduce the flow of waste and the flow of input energy, by utilizing locally available resources such as municipal solid waste, community wood waste, landfill gas, and biomass. It is the case for instance of Surrey (Canada)12.
12 http://www.surrey.ca/bylawsandcouncillibrary/R109-‐B5E8.pdf
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• Challenges to bring the principle to fruition District energy system requires a high density of construction to warrant the cost of constructing of such an infrastructure, and to reduce the loss due to the distance between the construction plant and the buildings it provides. This density can be assessed through the Floor Aera Ratio (FAR) tool, which is the total floor area of all buildings on a lot divided by the total aera of the lot. Implementing a high FAR can be handled through zoning code. Another challenge is to use a building assessment system to rate the energy efficiency of the building. This can be done using the LEED system. Retzlaff (9) states how LEED can be implemented in municipal policies, often only for government buildings. Some places require multiple kinds of buildings (in certain zoning districs, or with a minimum size requirements) to use LEED.
4th principle: Dynamic development in brownfield, greenfield and infill that is inspired by natural function A green city should take advantage of its development as a challenge to take
into account every aspect of its environment. Everything should be taken into account, from transportation to green openspace, through a mixing of uses, a high-‐quality building design to decrease energy consumption, a connection to the heating network, a social aspect of mixing the level of incomes. This is the case for Kronsberg Hannover in Germany, stated in (5). The example of ‘Bold Plan for New Orleans’ 13 enlightens how that development could be inspired by nature : levees could be built using ‘Sand Engine system’, as it is managed by Dutch for example. It is aimed at providing a fortification against beach erosion and protecting the coastline, without replenishment that could damage the marine ecosystem. Thanks to landscape management, many ecosystem services can be provided as stated in Marta Scwarz interview in ‘designing the Urban Landscape to Meet 21st Century challenges’ article14. The first one that pops up is planting. It is of great help in watershed management. This managment can provide the cleaning, capturing of water, retaining it, allowing it to go back to replenish aquifers. Planting provides the service of helping cleaning water and absorbing water. But it also helps to cut down particulate matter, clean the air. It also helps to struggle against erosion. It helps to moderate temperature fluctuations. And it makes things more pleasant as well, and in this way it helps people to be willing to live inside cities, and thus struggle against sprawling.
The Mesa Arts Center in Arizona, another project designed by Schwartz. “Most of our urban environments are not waterfronts and parks — they are our streets, our sidewalks, our utility corridors, parking lots,” says Schwartz. “It’s everything outside the building.”
13 http://www2.buildinggreen.com.proxy.the-‐bac.edu/article/bold-‐plan-‐new-‐orleans?ip_login_no_cache=3ca91b3b7a3982447a10102281fc1087 14http://e360.yale.edu/feature/martha_schwartz_urban_landscape_designs_to_meet_21st_century_challenges/2598/
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Another tool in place for designers and planners is to convert underutilized or abandoned properties to green space as assets. It implies developping community gardening, stormwater management, pocket parks. A great example studied in this class was Philadelphia work to refurbish vacant land into green space (10).
• Challenges to bring the principle to fruition It is vital to collaborate with the local community. Community gardening for example is a tool for community empowerement by involving people from the neighbourhood, like the Scouts in Philadelphia. Green space also helps the neighbourhod by producing positive enconomic impacts to the communities and to the real estate, as stated in Porfessor S. Watcher from Wharton School essay that demonstrates that greening has an impact of +37% on home values15. As stated in (10), it is also a tool to struggle against crime as vacant lots can turn out to be ‘havens for drug dealing, prostitution and other crimes’. This principle is also a financial challenge, that could be tackled through planning, as in Philadelphia. A Land Bank can be created to be able to handle the vacant land in the meantime.
CONCLUSION 5th principle: The green city as a nested system
To conclude, my final principle that sums the others up is to describe the green city as a nested system. The principle is that such a city must be designed at several scales – from the house to the block, from the aera to an entire region. As stated in (1), the decisions in one city affect the quality of environment and life in other places, as well as the overall health of the planet. Thinking the city at different scales helps anticipating all the impact of urban development. (1) also underlines the essential impact of different level of involvement, strong national initiatives can trigger creative bold initiatives at the city scale – for example in Netherlands strong energy codes for new housing help progress, inititiative from municipality can trigger sustainable initiatives at the neighborhoud scale, that could foster sustainable action at a household scale. All the dimensions of sustainability should be taken into account : from hazard to landscape, from vegetation to energy, from transportation to housing. There is the challenge to engage target groups in collaborative and interdisciplinary approaches. Everything in the green and sustainable city is nested.
15 http://gislab.wharton.upenn.edu/Papers/Green Investment Strategies How They Matter for Urban Neighborhoods.pdf
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FINAL GRADE AND COMMENT by BOSTON ARCHITECTURAL SCHOOL
BIBLIOGRAPHY
(1) City Reader -‐ Third edition, Edited by Richard LeGates and Frederic Stout (2) http://www.ecoliteracy.org/philosophical-‐grounding/core-‐ecological-‐concepts (3) Suburban nation, 10 How to make a town, 2000, Andres Duany, Elizabeth Plater-‐
Zyberk and Jeff Speck (4) Ewing, Bartholomew, Winkelman, Walters and Chen, Executive Summary from
the Growing Cooler Report, Urban Land Institute/Smart Growth America, 2007 (5) Farr, Sustainable Urbanism (6) The city reader – Frederick Law Olmsted – “public parks and the enlargement of
towns” (7) Planning for climate change – Patrick Condon-‐ Lincoln institute of land policy –
Land Lines-‐ January 2008 (8) Greening the Rust Belt, Joseph Schilling and Jonathan Logan, Journal of the
American Planning Association, Autumn 2008 (9) Retzlaff, Rebecca, "The Use of LEED in Planning and Development Regulations:
An Exploratory Analysis", Journal of Planning Education and Research, Vol. 29, No. 1 Fall 2009, pp. 67-‐77 Frey, Dunn and Cochran, The Greenest Building: Quantifying the Environmental Value of Building Reuse, Preservation Green Lab, National Trust for Historic Preservation, 2011, pp. 13-‐38 and 84-‐91
(10) Lyman, Francesca, "From Vacant to Verdant: Rethinking the Shrinking City", Parks & Recreation, July 2008. pp. 36-‐41
