Typomorphological Study of Built Environments based on Density Measures YEN YU CHEN
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Contents Introduction Research framework Research design Results Conclusion
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Introduction
Source: http://cone.gollnerfire.com/wpcontent/uploads/2015/09/EMspecturm-600x266.jpg
Electromagnetic spectrum 3
Introduction
Source: Penn State
Spectral signature → Object identification 4
Introduction
Farmhouses Apartment building High-rise building
?
Terraced housing
Taichung City, Taiwan
Spectral signature → Building typology? 5
Introduction
“When you see the particular, always look for the general” - Albrecht Penk
“Too much research is of purely local significance, failing to relate the particulars of individual places to a wider framework of thinking” - J. W. R. Whitehand
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Introduction
Density increases
High compactness
High building intensity
Low compactness
Low building intensity
Q: Is there a spectral signature for building types? A: Yes, based on DENSITY 7
Introduction
TYPOLOGY
MORPHOLOGY
Building forms
Over-the-Rhine, Cincinnati
J.N.L. Durand, 1809
Daniel Brian Ferdelman, 1997
(ARCHICTECTURAL)
(GEOGRAPHICAL)
Introduction
TYPOMORPHOLOGY
• Phylogenesis • Evolution • Typology
• Ontogenesis • Development • Morphology
Introduction
Typomorphology • Dialectic between building typologies and urban morphology • Explain how the built environment is produced by classifying systematically the elements which structure the physical form of cities over time Morphology
TYPE
Habitus
Typomorphology
Typomorphological framework of the built environment in the making Adapted from Pierre Gauthier, 2004
Research framework
Aim and objectives
Research aim: To demonstrate a methodology for typomorphological studies of the built environment based on density measures.
Research objectives: 1. 2.
3. 4.
Review existing density measures and conceptual framework of typomorphology Investigation in solving the problems found in existing practices of density measures Demonstration and validation of proposed methodology Evaluation and interpretation of analysis results
Literature review
Research design
Implementation
Results Conclusion 11
Research design
Density in urban planning - Introduction of density regulations since late 19th century - Density as an ideological agenda of urban professionals - Density as an indispensable tool in shaping urban form
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Persons Per hectare
Howard Ebenezer’s Garden City
3500 Persons Per hectare
Le Corbusier’s Radiant City
850 Persons Per hectare
Jane Jacob’s Greenwich Village 12
Research design
Density in urbanism terms generally describes the relationship between a given area and the number of certain entities in that area. i.e.
Population density
Dwelling density
Floor area ratio
population hectare
dwelling units hectare
floor area site area
Open space ratio
open space area floor area
density =
mass volume
or in short form:
m d= v
}
under the premises that the measured substance is HOMOGENEOUS Young’s modulus – density chart
WORKING DEFINITION
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Research design
Problems of integrating density measures into typomorphology:
a city is anything but HOMOGENEOUS
1.Subjection to MAUP 2.Ambiguity of spatial unit 3.Poor reflection of urban form 4.Preconception of type
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Research design
1
Subjection to MAUP
40 dw/ha
• Many density measures describe a part-to-whole relationship • Often represented as ratios of some occupier as the numerator, and a defined unit of area as denominator
50 dw/ha
• Definition of denominator is ambiguous and flexible 60 dw/ha Source: Berghauser Pont and Haupt (2010)
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Research design
2
Ambiguity of spatial unit
• Hierarchy is essentially one of containment, a given disposition by the higher order to the lower • Contributive vs Resultant form • The potentiality of the building is contained within the plot, and contrarily the plot is dispositive of the resultant building(s)
Source: Berghauser Pont and Haupt (2010) 16
Research design
Solution to problems 1 and 2
Plot as spatial unit of analysis Plot
Building type
(contributive form)
(resultant form)
Problematic scenarios Possible solutions Plot redrawn to resultant perimeter of combined plots
(1) Single plot consisting of multiple buildings of different building type; (2) Single building covering multiple plots; (3) Multiple buildings of different building type covering multiple plots.
Divide buildings according to intersecting plot boundaries
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Research design
3
Poor reflection of urban form
• Density measures has been criticized explicitly for its descriptive weakness of physical/spatial properties of urban form • The same density can be obtained with radically different building types, and the same type can be used to obtain different densities
75 dwellings per hectare
75 dwellings per hectare
75 dwellings per hectare
Identical FAR with different form
Source: Berghauser Pont and Haupt (2010) 18
Research design
Solutions to problem 3
Multivariate density measures • Ground Space Index (GSI) reflects compactness of development
• Floor Space Index (FSI) reflects building intensity
• Building height (L) average number of storeys of building(s)
• Open Space Ratio (OSR) indicates pressure of developed floor area on non-built space Building type clusters on Spacemate diagram M. Berghauser Pont, P. Haupt TU Delft 19
Research design
Solutions to problem 3
Linear programming / kernel density estimation • Enhances statistical profiling • Demarcation of cluster boundary • Identification of archetype
Concept of linear programming on Spacemate
Kernel density estimation of building type cluster 20
Research design
4
Preconception of type
• As type and typology concerning the built environment is convincingly cultural products, there can be no unifying or definitive way of classification • Generalization bears the latent danger in stereotyping that may blind us from seeing the emergent.
• “To observe, then, is to be content with seeing a few things systematically” – Foucault
pavilion
street
court
Source: Martin and March (1972) 21
Research design
Solution to problem 4
Exploratory clustering analysis Two-step clustering analysis
FSI
• Handles large datasets • Automatic determination of clusters
Clustering dendogram
Two-step clustering result on Spacemate
GSI
Clustering scree plot
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Research design
Study area
Base data
Taichung City, Taiwan Population: 2.7 million Area: 2,215 km²
Building footprint and parcel map of Taichung City, 2001
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Research design
Data cleaning
Data formulation
After exclusion of insignificant building structures, 234,820 building objects remain
Calculation of density measures CA
After merging of plots, 91,137 parcel objects remain
Cleaning off building extensions
Redrawing plot boundary
Formulated attribute table 24
Research design
Data analysis Explorative data analysis • • • •
Deduction of correlation between density measures Automatic determination of building type clusters Delimiting the density conditions of each building typology Interpolation of archetype and deviation for each building type
Empirical data analysis • • •
Semantic translation of discovered building typologies Identification of real-world examples Cross-referencing results with land use plan 25
Results
Interpreting density measures Descriptive statistics for density measure of Taichung City
Descriptive statistics of density measures provides an initial outlook on the spatial structure of Taichung City
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Results
Comparative study with Manhattan Descriptive statistics for density measure of Manhattan
Descriptive statistics for density measure of Taichung City
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Results
Spectral signature of building types Type 2
Type 3 Type 4
Type 5
Type 6
Type 7
Type 8 Type 1
Type 9
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Results
Spectral signature of building types
Low intensity building types
Moderate intensity building types
High intensity building types
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OSR(min) = 0.00
Results
Typological process
③
FSI(max)② = 8.48
• Demonstrate variation between archetype and deviations within typologies
+
GSI(min) = 0.46
①
①
③ GSI(max) = 0.99
② FSI(min) = 3.59
① Deviation (min)
② Archetype
③ Deviation (max)
• Understanding the conditions and context of typological changes • Reflection of social demands 30
Results
Typological process
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Results
Co-occurrence of densities Bivariate correlation of density measures GSI, FSI, OSR, and L
Implications of building coverage
Implications of building height
Scatterplot matrix of GSI, FSI, OSR, and L 32
Results
Typological outliers
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Results
Typological discontinuity • Building Act of Taiwan requires buildings higher than 6 storeys tall be equipped with elevators • Buildings will leapfrong from 5 storeys to 11 storeys high, skipping the height in between all together • Makes sense economically to minimize marginal cost of elevator installation by building higher till a point of desired profitability 34
Results
Spatial density distribution of building types
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Results
Spatial density distribution of building types
Land use map of Taichung City
Spatial distribution of Type 4 (high-rise buildings)
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Results
Revision of urban theories
Transect planning Duany and Talen, 2002 37
Conclusion
The proposed methodology provides: 1. 2. 3. 4. 5.
High level of spatial resolution by using parcel as the unit for analysis Multivariate in the description of built form through density measures Exploratory and non-stereotypical in the classification of building types Systematic in the statistical and semantic profiling of discovered types Explanatory of emergent spatial structures Correlation between density measures
Density profile of cities
Density spectrum for classifying building typologies
Spatial distribution of building types 38
Results
Limitations
FSI
• Requires parcel data, which may be hard to acquire • Clustering results are highly reliant on the quality of dataset • Results of kernel density estimation varies with different search bandwidths
Parcel data
Clustering results
GSI
Kernel density bandwidth 39
Results
Future work • Automization of the methodology into an analysis tool • Spatial-temporary analysis of the evolution and morphology of building types
Gapminder http://www.gapminder.org/
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THANK YOU FOR LISTENING Typomorphological study of built environments based on density measures YEN YU CHEN Advisor: LIN HAN LIANG
Master’s thesis presentation, 26 June 2015 Department of Urban Planning, National Cheng Kung University 41