Urban and Site Planning
An overview of how architecture scales from individual buildings to master-planned communities and urban centers.
The Fundamentals of Urban Planning
Shaping the growth and development of cities.
Why Urban Planning Matters
Urban planning is the technical and political process concerned with the development and design of land use and the built environment. In the Philippines, this is heavily influenced by rapid urbanization and the need for resilient infrastructure.
- The Image of the City (Kevin Lynch): A seminal theory arguing that people understand cities through five key elements: Paths (channels of movement), Edges (boundaries like rivers or walls), Districts (medium-to-large areas with a common character), Nodes (strategic focal points like plazas), and Landmarks (reference points).
- The Garden City Movement (Ebenezer Howard): An early 20th-century urban planning concept proposing self-contained communities surrounded by "greenbelts," combining the best aspects of town and country living while avoiding the overcrowding and pollution of industrial cities.
- Radiant City (Le Corbusier): A highly influential, unrealized modernist urban masterplan focusing on linear, high-density skyscraper blocks surrounded by vast open green spaces and rigidly separated zones for living, working, and leisure.
- New Urbanism: A modern planning movement promoting walkable, mixed-use neighborhoods with high-density housing and commercial spaces, pushing back against the automobile-centric urban sprawl of the late 20th century.
- Zoning: Dividing land into zones (e.g., R-1 for low-density residential, C-2 for medium commercial, I-1 for light industrial) to dictate permissible uses, building heights, and development standards, ensuring compatible land uses.
- Transportation: Designing efficient networks for vehicles, pedestrians, and public transit to reduce congestion (a major issue in Metro Manila) and improve connectivity.
- Infrastructure: Planning for the essential services required for a city to function, such as water supply, sanitary sewers, storm drainage (critical for flood management), power grids, and telecommunications.
- Sustainability and Resilience: Creating urban environments that minimize environmental impact, reduce carbon footprints, and, importantly for the Philippines, promote resilience against climate change impacts like stronger typhoons and rising sea levels.
Key Takeaways
- Urban planning involves organizing land use, transportation, and infrastructure at a city scale to ensure functional and resilient cities.
- Zoning ordinances dictate permissible uses and building standards to prevent conflicting developments.
Transit-Oriented Development (TOD) and New Urbanism
Modern paradigms in urban planning to combat urban sprawl.
Combating Car-Centric Sprawl
Traditional mid-20th-century zoning often segregated uses, leading to sprawling suburbs and heavy reliance on private automobiles. New approaches seek to reverse this trend.
- Transit-Oriented Development (TOD): Development centered around public transit stations. It typically features a mix of uses (residential, commercial) within a walkable half-mile radius, maximizing ridership and reducing driving.
- New Urbanism: An urban design movement promoting walkable neighborhoods containing a range of housing and job types. It emphasizes traditional neighborhood design (TND) with a clear center, public spaces, and interconnected street grids (vs. cul-de-sacs).
- Smart Growth: A broader policy framework prioritizing the development of existing urban areas over building on untouched land. It advocates for compact building design and a variety of transportation choices.
- Philippine Context: Implementing TOD is crucial for mitigating severe traffic congestion in Metro Manila and improving access to mobility.
Key Takeaways
- TOD clusters mixed-use development around public transit hubs, reducing dependence on private vehicles.
- New Urbanism promotes traditional, walkable, human-scaled neighborhood design.
Regulatory Planning Controls
The mathematical parameters that dictate building volume and site occupancy.
Zoning Metrics in the Philippines
The National Building Code (PD 1096) and local zoning ordinances define strict parameters that architects must follow to prevent overdevelopment and ensure adequate light, air, and open space.
Setbacks:
The required minimum distance between the building footprint and the property lines (front, sides, and rear). Setbacks provide open space for ventilation, fire separation, and future road widening.
Percentage of Site Occupancy (PSO):
The maximum area of the lot that can be covered by the building footprint, expressed as a percentage. For example, a 70% PSO on a 100 sqm lot means the ground floor cannot exceed 70 sqm, leaving 30% as unpaved open space (Total Open Space within Lot or TOSL).
Floor Area Ratio (FAR) / Floor to Lot Area Ratio (FLAR):
The ratio of a building's total Gross Floor Area (GFA) to the size of the piece of land upon which it is built. It dictates the overall bulk or volume of the building. A FAR of 3.0 on a 100 sqm lot means the total floor area across all floors cannot exceed 300 sqm.
Zoning and Site Analysis Simulator
Adjust the setbacks and building dimensions to see how local zoning laws dictate the permissible building envelope and Percentage of Site Occupancy (PSO) on a 20m x 30m lot.
Zoning Regulations
Building Design
Total Lot Area:600 sq.m
Allowable Envelope:352 sq.m
Building Footprint:150 sq.m
Percentage of Site Occupancy (PSO):25.0%
Building fits within allowable zoning envelope.
Key Takeaways
- Key regulatory controls strictly govern building footprint and volume to ensure safety and comfort.
- Setbacks, PSO, and FAR are critical metrics in the Philippine National Building Code for preventing overdevelopment.
Site Analysis
The critical first step before any design begins.
Understanding the Context
Before an architect can design a building, they must thoroughly understand the site upon which it will sit. Site analysis involves evaluating the physical, biological, and cultural attributes of a parcel of land.
Checklist:
- Topography: The shape and elevation of the land (slopes, flat areas, natural drainage patterns). Crucial for determining cut-and-fill requirements and foundation types.
- Climate (Microclimate): Sun paths (solar orientation), prevailing wind directions (the northeast monsoon Amihan and southwest monsoon Habagat in the Philippines), temperature, and precipitation levels.
- Vegetation and Ecology: Existing mature trees to be preserved, natural habitats, and soil bearing capacity (e.g., adobe rock vs. soft clay).
- Access and Circulation: Existing roads, pedestrian paths, public transit links, and identifying the "highest and best use" based on street frontage.
- Regulatory Constraints: Easements (e.g., along esteros or fault lines), setbacks, zoning laws, and building height restrictions (BHL - Building Height Limit).
Key Takeaways
- Site analysis is a rigorous process of evaluating a specific property's physical topography, climate, and regulatory constraints before design begins.
- Understanding a site's unique characteristics is necessary to design buildings that integrate seamlessly with their environment.
Principles of Site Design
Organizing spaces and structures on a specific parcel of land.
Spatial Organization
Site design is the process of arranging buildings, roads, walkways, landscaping, and other elements on a site to create a functional and aesthetically pleasing environment.
- Orientation: Positioning buildings to maximize energy efficiency. In the tropics, this generally means orienting the longest building axis East-West to minimize the surface area exposed to the harsh morning and afternoon sun, while orienting windows North-South to capture indirect light and prevailing breezes.
- Circulation: Designing clear and safe paths for vehicles and pedestrians, minimizing conflicts between the two. Ensuring adequate turning radii for fire trucks and delivery vehicles.
- Open Space: Integrating plazas, parks, and courtyards to provide relief from the built environment, manage stormwater runoff naturally, and foster social interaction.
Key Takeaways
- Effective site design responds to natural topography, climate, and the surrounding urban context.
- It balances aesthetic aspirations with functional requirements like circulation, drainage, and zoning regulations.
Urban Theories and Zoning Controls
Historical models and regulatory tools in city planning.
Influential Urban Planning Theories
- Ebenezer Howard's Garden City: A utopian response to industrial slums. Proposed self-contained communities surrounded by greenbelts, balancing city amenities with country nature, heavily influencing modern suburban planning.
- Le Corbusier's Radiant City (La Ville Radieuse): A high-density, modernist vision of towering skyscrapers set within vast parks. Aimed to maximize sunlight, open space, and vehicular efficiency. Heavily criticized for isolating pedestrians and destroying traditional street life.
Zoning and Development Controls
Municipalities use zoning ordinances to regulate land use and building bulk.
- Zoning Types: Land is typically categorized into R (Residential), C (Commercial), I (Industrial), and Institutional zones. Zoning prevents conflicting uses (e.g., placing a loud factory next to a quiet neighborhood).
- Floor Area Ratio (FAR): The ratio of a building's total floor area to the size of the piece of land upon which it is built. A FAR of 2.0 on a 1000 sqm lot allows a total building area of 2000 sqm. It controls building volume.
- Percentage of Land Occupancy (PLO): The maximum percentage of the lot area that can be covered by the building footprint. Ensures sufficient open space for drainage, light, and ventilation.
Key Takeaways
- Effective site design arranges buildings to optimize solar orientation (minimizing East-West exposure in the tropics).
- It safely manages pedestrian and vehicular circulation and creates valuable open spaces for communities.
Zoning and Land Use
The legal frameworks that regulate how land can be utilized to ensure orderly urban growth.
Development Controls
Zoning laws (implemented via Local Government Units/LGUs in the Philippines) dictate what can be built and how dense it can be.
- Land Use Classification: Categorizing land into zones such as Residential (R-1, R-2, R-3), Commercial (C-1, C-2), Industrial, Institutional, and Parks/Recreation to prevent incompatible uses (e.g., a heavy factory next to a school).
- FAR (Floor Area Ratio): The ratio of a building's total gross floor area to the size of the piece of land upon which it is built. It regulates density. A FAR of 2.0 means you can build 20,000 sq.m. of floor space on a 10,000 sq.m. lot (e.g., a 2-story building covering the whole lot, or a 4-story building covering half).
- Setbacks: The mandatory minimum distance a building must be placed back from the property line, street, or other structures. Setbacks ensure natural light, ventilation, privacy, and fire separation between buildings.
- AMBF (Allowable Maximum Building Footprint) & PSO (Percentage of Site Occupancy): Regulations that limit how much of the ground level lot can be covered by the building, ensuring sufficient unpaved open space (TOSL - Total Open Space within Lot) for drainage and landscaping.
Key Takeaways
- Zoning regulations legally enforce the separation of incompatible land uses to protect public health, safety, and welfare.
- Development controls like FAR, Setbacks, and PSO dictate the maximum three-dimensional volume and density a building can legally achieve on a specific site.
The Image of the City and Design with Nature
Seminal theories in urban perception and ecological planning.
Lynch and McHarg
Two foundational theorists significantly shaped modern urban and site planning.
- Kevin Lynch - "The Image of the City": Lynch studied how observers take in information of the city. He identified five basic elements that people use to construct their mental map of a city:
- Paths: Channels of movement (streets, walkways).
- Edges: Linear boundaries or barriers (rivers, walls).
- Districts: Medium-to-large sections of the city with a distinct, recognizable character.
- Nodes: Strategic focus points or intersections.
- Landmarks: External point references (towers, monuments).
- Ian McHarg - "Design with Nature": Pioneered the concept of ecological planning. He introduced the method of map overlay (the precursor to modern GIS), where various ecological factors (slope, soil, hydrology, vegetation) are mapped to identify the most suitable and least destructive areas for development, advocating that human settlement should respond directly to natural systems.
Key Takeaways
- Kevin Lynch's five elements (Paths, Edges, Districts, Nodes, Landmarks) are essential for creating legible, navigable urban environments.
- Ian McHarg's ecological overlay method established the foundation for environmentally sensitive site planning and modern GIS analysis.
Site Grading and Drainage
Manipulating topography to ensure proper water management and site accessibility.
Grading and Drainage Principles
Proper site engineering is crucial to prevent flooding, erosion, and structural damage to the building foundation.
- Grading: The process of reshaping the land's surface. A critical rule is to always slope the ground away from the building foundation to prevent water accumulation.
- Surface Drainage: Utilizing swales (shallow vegetated ditches) and the natural slope of the land to direct rainwater toward catch basins or municipal storm sewers.
- Subsurface Drainage: Using perforated pipes (French drains) underground to manage groundwater and prevent hydrostatic pressure against basement walls.
- Permeable Surfaces: Utilizing porous paving materials and rain gardens to allow water to infiltrate the soil, reducing runoff and recharging groundwater aquifers.
Key Takeaways
- Site grading must ensure water moves away from structures while minimizing disruption to natural drainage patterns.
- Integrating permeable surfaces and swales helps manage stormwater sustainably on-site.
Zoning, Land Use, and FAR
The regulatory frameworks governing urban development.
Development Controls
Urban planning relies on legal instruments to manage growth, density, and the compatibility of adjacent uses.
- Zoning: The legislative process by which a local government divides land into zones (e.g., residential, commercial, industrial, agricultural). Each zone has specific regulations regarding:
- Permitted Uses: What can be built (e.g., single-family homes, high-rise apartments, retail).
- Building Envelope: Height limits, setbacks (distance from property lines), and lot coverage.
- Floor Area Ratio (FAR): A critical density control mechanism. It is the ratio of a building's total gross floor area to the size of the piece of land upon which it is built.
- FAR = Total Floor Area / Total Lot Area
- A FAR of 1.0 means the total floor area equals the lot area (e.g., a 1-story building covering the whole lot, or a 2-story building covering half the lot).
- High FARs are typical in dense urban centers (like CBDs), encouraging taller buildings.
- Planned Unit Development (PUD): A zoning classification that allows for flexible, mixed-use developments that might not strictly adhere to traditional zoning requirements but offer community benefits (like public parks or affordable housing).
Key Takeaways
- Zoning dictates what can be built and where, separating incompatible uses.
- FAR is the primary tool for regulating the density and bulk of buildings in an urban area.