Understanding Urban Fabric: Morphology, Elements, and Growth

Posted on Feb 13, 2025 in Architecture

Urban Fabric: Planar and Volumetric Shapes

Urban morphology: Conditions and characteristics of the shape and dimensions of the built environment.

Planar shape: Two-dimensional analysis, divided into streets, blocks, and public spaces.

Volumetric shape: Three-dimensional analysis.

Elements of Urban Fabric

  • Blocks: Floor area, built or unbuilt, externally bounded by streets or public spaces.
  • Streets: Linear public space limited by two blocks, linear elements for channeling fluxes.
  • Open spaces: Public spaces for urban life, e.g., urban parks, squares, gardens.

Urban Fabric Typologies

Origin:

  • Spontaneous: Growing naturally, e.g., Toledo.
  • Planned: Being planned, e.g., Barcelona.

Layout:

  • Irregular: Organic shapes in plan, e.g., Cairo.
  • Grid: Orthogonal grid, e.g., New York City.
  • Radical: Concentric, e.g., Israel.
  • Linear: E.g., Arturo Soria.

Urban growth phases:

  • Historical center
  • Planned expansion (19th-20th centuries)
  • Peripheral neighborhood, e.g., Las Rozas

Block Analysis

  • Block boundary: Perimeter line separating the plots from the public realm, dividing private from public spaces.
  • Plots: Central element in the configuration of the urban fabric, defining the conditions for buildings.
  • Lines: Perimeter lines separating one property from another:
    • Front: To public space.
    • Rear: Opposite to frontal line.
    • Side: To the side of the plot.

Street Analysis

  • Street width: Distance between opposite block boundaries (road + sidewalks).
  • Slope: Longitudinal street level.

Street Classification

According to hierarchy:

  • Primary: Large metropolitan avenue for traveling across the city, high-level traffic.
  • Secondary: Communication between different areas of the neighborhood.
  • Tertiary: Local communication within an area or neighborhood.
  • Pedestrian: Just for people to walk.

According to traffic segregation:

  • Unimodal: For a certain user.
  • Plurimodal: For various users, such as cars and pedestrians.
  • Coexistence: Several users sharing the space, use of “shared space” principles.

According to street width:

  • Narrow: Less than 8m.
  • Medium: 8-20m.
  • Wide: More than 20m.

Volumetric Shape: 3D Analysis

Key issues: Layouts and characteristics of the buildings in plots and by aggregation, in blocks.

Building Typologies

  • Aligned: Front building facade is on the front line.
  • Setback: Front building facade is separated from the front line.
  • Isolated: Facades separated from any lines.
  • Building line: Horizontal projection of all facades excluding heights, balconies, or small terraces.
  • Building depth: Maximum distance from the front line to the back facade of the building.
  • Plot coverage: Ground built-up area divided by the total plot area (%).
  • Built-up area: Sum of all story areas (m2).
  • Floor area ratio: Built-up area divided by the plot area (m2b/m2f).
    • Net: A plot, a block, or several blocks within a certain urban sector.
    • Gross: Considering an entire sector including streets, sidewalks, public space.

Image of the City: Lynch Method

Observing cities to understand what elements generate powerful images. Two basic analyses: expert fieldwork and inhabitant vision (surveys and interviews, drawings of the cities are also required).

Elements Configuring the Image of the City (Kevin Lynch)

  • Paths: Ways followed by the observer normally, occasionally, or potentially. We observe the city through them, and they connect and organize the other elements, e.g., streets, rivers, highways.
  • Edges: Boundaries between areas, linear ruptures of continuity, can be fences that separate urban sectors or union of areas, e.g., walls, rivers, linear parks, streets, railways, like Gran Via, La Castellana, or Paseo del Prado.
  • Districts: Recognizable parts of the city with a common character, e.g., building style/height, parks, types of street, activities, people.
  • Nodes: Strategic points of the city in which the observer enters, they are intensive points to reach or set out from, they can be concentrations or confluences, e.g., Atocha, Sol, Plaza Mayor.
  • Landmarks: Reference points external to the observer, they play a critical role for orientation in the city, e.g., advertisements, subway signs, statues.

Legibility of the city: Image attribute, also the capacity to recognize and organize the different parts of the urban landscape in a consistent pattern.

Image Attributes
  • Identity: Recognition of the objects as a different entity, e.g., Venice.
  • Structure: Spatial or pattern relationship between the objects and the observers.
  • Meaning: Emotional or practical meaning for the observer.

Housing: Residential Densities

According to the elements:

  • Dwelling densities: Number of dwellings/hectares.
  • Population densities: Number of inhabitants/hectares.

According to the area:

  • Gross: Entire sector (block + street + open space).
  • Net: Just land for buildings.

Housing Typological Analysis

  1. Historical center
  2. Housing in the urban expansion
  3. Linear block
  4. Single-family housing
  5. New urban sector

Evolution: Urban Growth

The transformation of the city.

Basic Typologies of Urban Growth

According to spatial conditions of growth:

  • Continuous:
  • Discontinuous: e.g., Tres Cantos.

According to regulation conditions:

  • Unplanned: e.g., Madrid city center.
  • Planned: e.g., Barcelona and Madrid urban expansion.
  • Continuous and planned: e.g., Salamanca.
  • Continuous and unplanned: e.g., Madrid center.
  • Discontinuous and unplanned: e.g., Vallecas.
  • Discontinuous and planned: e.g., Ciudad Lineal, Tres Cantos, London.
Regulatory Elements of Urban Growth
  • Limiting factors (Barriers): Natural and artificial, e.g., rivers, highways, walls, mountains.
  • Growth promoters (Nodes): Specific elements of attraction, e.g., universities, parks, concentration of activities.
  • Lines: Natural and artificial connectors, e.g., rivers, paths, roads.
Levels of Analysis
  • Microscale: Changes in the urban fabric, e.g., plots, blocks, buildings, open spaces (segregation: 1 block or plot is divided and aggregation: join of 1 block or plots).
  • Urban scale: Growth of the city by adding elements, blocks, or urban areas (single elements: blocks, urban areas: complete urban sectors).
  • Territorial scale: Effect of urban growth in broader urban environment developments, facilities, and new settlements.
Effects of Urban Growth in Territory
  • Dispersed actions: Peripheral urban areas (discontinuous growth).
  • Fusion: Spatial union of settlements, with the same administrative unit (continuous growth).
  • Conurbation: Spatial union of settlements, with administrative autonomy (continuous growth).
  • New settlements: Planned urban centers designed to accommodate the growth of cities (discontinuous growth).

Analysis of Land Users Structure

  1. Housing: Activities related to permanent accommodation, location factors (accessibility, public amenities, building quality), housing division on the plot (single-family houses, collective house).
  2. Industrial: Activities production, transformation, storage, and distribution of goods, location factors (incompatibility with housing, higher land value in the city center, large plots more available in the outskirts), categories (industrial production, industrial trade, maintenance of domestic articles and vehicles repairs).
  3. Services: Activities related to non-producing materials services of goods, which are provided to citizens, classification (tertiary use and public facilities), tertiary use (commercial uses, hostelry, offices, leisure), public facilities (open to all, benefit to the entire community and location factors it has to be accessible for all, e.g., swimming pools, library, green areas).
  4. Urban infrastructure: Facilities that support other urban activities (classification like transport, energy, water supply sanitation and waste managements, telecommunication).

Levels of Land Use Analysis

  • Space needs: Adequate dimensions for the activities.
  • Location needs: Predominating land uses and conditions for incompatible or tolerable land uses.
  • Functional needs: Existence of infrastructure networks and facilities urban services.