DES 230 Final exam Flashcards
Study (44 cards)
The Five Rules
- Systems View
- Recognize Patterns
- Lighter, Cheaper, Greener Infrastructure
- Adaptability to market shifts
- Resilience through affordable housing
The Seven Principles
- Streetcar City
- Interconnected Street system
- Good jobs close to affordable homes
- Interconnected Green System
- Lighter, Greener, Cheaper Infrastructure
- 5 Minute Walk
- Diversity of Housing types
Alexanders 15 Principles
Order not important
1. The Void
2. Contrast
3. Positive Space
4. Levels of Scale
5. Boundaries
6. Inner Peace
7. Alternating Repetition
8. Graded Variation
9. Good Shape
10. Deep Interlock
11. Roughness
12. Strong Centres
13. Echoes
14. Local Symmetries
15. Not - Separateness
How are cities related to the Climate Crisis?
- 80% of people in Canada live in cities
- The Urban pattern can have a great effect on its production of GHG -> North America around double other nations such as Japan
Views for future sustainable cities?
Two Contrasting visions:
Flintstones (return to nature – going back to land// very light footprint// growing your own vegetables)
Jetsons (high-tech solutions – Automatic driverless cars // Proposed Visuals from Eco-city in China// very less pedestrians).
-> In reality neither of these are feasible
What kind of city is Vancouver?
Vancouver // Distributed / flat city instead of vertical one // A streetcar city.
What is a “Flat” City?
cities with even density and tightly packed mixed land uses
perform best on both transportation and building energy use.
What was walking distance in minutes before the Streetcar Era and by how much did it increase?
20-minute walk circle
Increase of 20-minute distance influencing city and building forms.
Characteristics of the Streetcar City?
Linear commercial activities
Works as a grid not as a node
Walkability: 5-minute walking distance (400m or ¼ of a mile)
For the interurban line it is10- 20-minute walk. Example – Ohio and midwest.
What happened to Streetcars?
Shift from streetcar to automobile-dominated urban landscapes(1960-1970s).
Eliminate the streetcar service // New buses // Arterials // Strip commercials, big parking lots, a lot of traffic.
Tragic history of streetcars systems // contractual obligation for new buses - streetcars were burned // Reason – to limit competition // Big Oil // Auto industry.
They didn’t foresee the congestion, global warming, and pollution.
The City of Toronto has a legacy of an almost intact streetcar system.
Why is an Interconnected Street(Semi-lattice) system better than dendritic?
Cheaper houses streets on through streets = Subtle class distinction is visible with cul de sacs (designed to do this)
Designed to frustrate trips
Intersections impossible to cross by foot
Big box magnets
400% more trips! which means 60% more pedestrian fatalatities (designed to accommodate more cars = more velocity = more deaths)
Different forms of interconnected
Rectilinear - Ex. Vancouver 640ft x 320ft, Most common form,
Radial - Ex. Washington -Intersecting radials overlaid on a traditional grid (N/S orientation)
Traffic movement potentially more direct but intersections very complex
The Informal Web - Ex. Cambridge, Massachusetts
Main arterials from direct lines from one square to another.
In between these arterial 100x200m parcels TYP.
squares oriented usually parallel to arterials
Spaces in between and informal grid of more or less traditional blocks
Romantic pattern (Warped Grid) - Ex. Riverside, Illinois
Operates as a grid like network but naturalized / warped
Can work with topography and natural drainage = best for complex landscape with complex topography
First designed by F. L. Olmsted in 1870.
“Every view is a new view”
Other Case Study: Shaughnessy District
North and south Orientation VS East and West
Seattle is NS, Vancouver is EW
EW ->Traffic movement easier but slighter disadvantage for vehicles (which is a good thing) = they have to stop more and are forced to move a lot slower because there are more intersections.
Direct views towards a certain scenery (ex. Vancouver: view to mountains)
what do neckdowns do?
Shorten crossing distance
What is Side Friction
A lot of the things appear to be visual obstacles NOT like speedbumps = forces cars to slow down in a queuing street
Such as shrubs, or even cars.
Road Size
Typical cul de sac = 20’ wide street = designed to accommodate fire trucks / ladder on both sides with a turning radius of 41’
Vancouver —————
1.8 metre = sidwalk on each side
2.3 metre = boulevard / grass areas or trees for canopies on each side
8.2 metre = road
per building code typically 5.0 metre building front setback
Ideal Density found by Condon
10DU per acre
More efficient Building?
Highrise :( nope - Continuous glass facade - terrible insulator
Not efficient
The velocity of the wind increases as you go up
Medium density lowrise? Yes! - Trees can shade it
Less heat is lost through sharing walls
What is the BIG housing issue?
Cities rapidly expanding
Lots of old people because of lowered fertility rate and the baby boom
lots of immigration
new demographics require different forms of housing than are available
What is the Emerald Necklace?
Designed by Olmsted
Runs from the centre of Boston, out into the suburbs
Best example of a linked system of parks and linear routes
Still functional 150 years after its advent
Combination of infrastructural elements of rail, road, drainage, potable water, ecological systems
Emerald Necklace is a more important model than Central Park because its more than a aprtk. Its an urban armature. Its a system.
Damascus Area Design Workshop Plan - Urbanism in a Green Frame
FIVE RULES:
Nature out front, not out back
Use natural systems to bound and protect neighbourhoods
Design the ecological parkway
Expand the system indefinitely
Provide an alternative movement system
What is causing the most damage to the watershed?
Urban stormwater discharge is identified as a major threat to aquatic life, notably fish, through changes in stream water – speed, amount, and temperature rather than just dirt/ pollutants.
-Systems of the city - rooftops and pavements - designed to get rid of the water as fast as possible - no puddles - removed within an hour
VS a forest - which holds the water and allows it to remain available for a long time
Rate of discharge is much slower
Minimum Infiltration rate
Green infrastructure – 1” a day or 1mm per hour infiltration across site
TIA VS EIA
Total Impervious Area (TIA): Measures the overall coverage of impervious surfaces (e.g., roads, rooftops) in an area, indicating how much land prevents water infiltration.
Effective Impervious Area (EIA): Considers the hydrological impact of impervious surfaces, factoring in how water is managed or directed (e.g., to pervious areas for absorption).