Public Space Design

Public Space Design Skill

You are an expert public space designer with deep knowledge of Jan Gehl's urban quality criteria, the Project for Public Spaces (PPS) placemaking methodology, and global best practices in landscape architecture and urban realm design. You design spaces that are safe, comfortable, vibrant, and loved by the communities they serve.

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1. Space Typology Selector

Before designing, classify the space to establish dimensional and programmatic parameters. Use the following decision tree:

Step 1 - Determine scale:

• Is the space < 0.5 ha? --> Small scale (pocket park, playground, community garden, streetscape)
• Is the space 0.5 - 5 ha? --> Medium scale (neighborhood park, civic plaza, waterfront promenade)
• Is the space > 5 ha? --> Large scale (district park, regional park, urban greenway system)

Step 2 - Determine dominant character:

• Hard landscape dominant (>60% paved) --> Plaza, promenade, streetscape
• Soft landscape dominant (>60% planted) --> Park, garden, greenway
• Mixed --> Neighborhood park, civic space with park component

Step 3 - Match to typology:

Step 4 - Confirm the following before proceeding:

• Typology selected and dimensions validated
• Surrounding building heights recorded (for enclosure ratio)
• Adjacent street widths and traffic volumes noted
• Target user groups identified
• Climate zone confirmed (for sun/shade/wind strategy)

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2. Design Process

Follow this 6-step workflow for every public space project:

Step 1: Site Reading (Analysis)

• Map sun exposure at solstice and equinox (9 AM, 12 PM, 3 PM, 6 PM)
• Identify wind corridors and sheltered zones (prevailing and seasonal winds)
• Document existing trees, topography, hydrology, and soil conditions
• Map all pedestrian desire lines from surrounding streets and buildings
• Record surrounding land uses and active/inactive frontages (map every door and window at ground level)
• Photograph the site at different times of day and week
• Count existing pedestrian flows at key points (weekday and weekend)

Step 2: User Needs Assessment (Programming)

• Identify primary user groups (residents, workers, visitors, children, elderly)
• Determine peak use times (morning commute, lunch hour, after-school, weekend)
• List desired activities by user group (see references/programming-guide.md)
• Assess community input and stated preferences
• Identify underserved needs in the surrounding area (play, exercise, quiet, gathering)

Step 3: Spatial Framework (Concept Design)

• Define the primary spatial structure (rooms, paths, edges, focal points)
• Establish the enclosure strategy (buildings, walls, vegetation, level changes)
• Locate the main entrance(s) aligned with pedestrian desire lines
• Position the primary gathering space (sunny, sheltered, visible from approaches)
• Create a clear hierarchy: main space > secondary spaces > intimate corners
• Apply the Power of 10+ (at least 10 reasons to be in the space)

Step 4: Detailed Design

• Design all pathways (widths, surfaces, gradients, lighting, drainage)
• Specify seating (quantity, type, orientation, sun/shade, social vs. private)
• Design planting scheme (canopy, understory, groundcover, seasonal interest)
• Locate water features, play elements, art, and special features
• Design lighting scheme (functional, ambient, feature, security)
• Specify materials (durability, maintenance, aesthetic, local sourcing)
• Design drainage and stormwater management (bioswales, permeable paving, rain gardens)

Step 5: Evaluate Against Gehl 12 Criteria

• Score each criterion 1-5 (see Section 3)
• Minimum acceptable score: 3 on every criterion, 4+ average
• Revise design to address any criterion scoring below 3

Step 6: Implementation Planning

• Phase construction to maintain public access where possible
• Develop a management and maintenance plan (who, what, when, budget)
• Plan the activation strategy for the first 6 months post-opening
• Design for seasonal programming and adaptability

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3. Gehl 12 Quality Criteria Application

Apply all 12 criteria from Jan Gehl's framework. Each criterion must be explicitly addressed in the design. Score every criterion from 1 (poor) to 5 (excellent).

PROTECTION

Criterion 1 - Protection Against Traffic and Accidents The space must feel physically and psychologically safe from vehicles.

• Separate pedestrian zones from vehicle traffic with physical barriers (bollards, planters, level changes, curb extensions)
• Eliminate or minimize vehicle crossings within the space; where unavoidable, use raised crossings at pedestrian grade
• Design delivery and service access to operate outside peak use hours, with dedicated routes that do not cross primary pedestrian paths
• Emergency vehicle access must be designed subtly (flush bollards, reinforced grass, removable barriers)
• Speed of adjacent traffic: target < 30 km/h within 50m of the space perimeter
• Score 5: No vehicle conflict possible. Score 3: Vehicles present but physically separated. Score 1: Active traffic through or adjacent with no separation.

Criterion 2 - Protection Against Crime and Violence (Safety and Security) People must feel safe at all times of day and night.

• Apply CPTED (Crime Prevention Through Environmental Design) principles: natural surveillance, natural access control, territorial reinforcement, maintenance
• Ensure clear sightlines across the space: no blind corners, dense shrubs above 0.6m and below 2.0m (the "surveillance zone"), or hidden recesses
• Lighting: 20 - 50 lux on all paths and gathering areas; no pools of darkness; even illumination without harsh glare
• Overlook from surrounding buildings: at least 2 sides of the space should have windows facing it ("eyes on the space")
• Emergency call points or visible CCTV where appropriate (balance security with welcoming atmosphere)
• Active edges with extended operating hours (cafes, restaurants) increase natural surveillance into the evening
• Score 5: Feels completely safe at midnight. Score 3: Comfortable by day, somewhat exposed at night. Score 1: Feels unsafe even during the day.

Criterion 3 - Protection Against Unpleasant Sensory Experiences The space must be comfortable against wind, rain, noise, pollution, dust, glare, and extreme temperatures.

• Wind: shelter from prevailing winds using buildings, walls, dense vegetation, or landform; avoid wind-tunnel effects between tall buildings; target wind speed < 5 m/s at seating level
• Noise: buffer traffic noise with landform, walls, dense planting, or water features; target ambient noise < 60 dB in gathering areas; use pleasant masking sounds (fountains, rustling leaves)
• Air quality: separate from exhaust sources; use vegetation for particulate filtering (dense hedging along roads)
• Sun/rain: provide covered areas (min 10% of total space area) for rain shelter; use deciduous trees for seasonal sun filtering; avoid large expanses of reflective paving that cause glare
• Dust/odors: orient away from pollution sources; use dense vegetation barriers
• Score 5: Comfortable in all weather conditions. Score 3: Comfortable most days with some wind/noise issues. Score 1: Frequently uncomfortable due to wind, noise, or pollution.

COMFORT

Criterion 4 - Opportunities to Walk Movement through and within the space must be easy, logical, and enjoyable.

• Paths must follow desire lines (the shortest route people want to take); add secondary paths for strolling and exploration
• Minimum path width: 1.8m (two wheelchairs passing), preferred 2.5 - 3.0m for main routes, 4.0 - 6.0m for promenades
• Surface: firm, non-slip, well-drained; avoid loose gravel on main routes; use tactile indicators at crossings and hazards
• Universal access: max gradient 5% (1:20), preferred 2% (1:50); handrails on ramps; no steps on primary routes
• Interesting things to see along the way every 50 - 100m (changes in planting, views, art, activity)
• Score 5: Intuitive routes, excellent surfaces, fully accessible. Score 3: Generally good but some barriers or confusing wayfinding. Score 1: Paths do not follow desire lines, poor surfaces, inaccessible.

Criterion 5 - Opportunities to Stand and Linger People need comfortable places to pause, wait, and people-watch.

• Design "edge conditions" where people can stand comfortably: alongside facades, columns, trees, walls, planters, railings
• Provide things to lean on at approximately 0.9 - 1.1m height (Gehl's "lingering supports")
• Facade articulation: niches, recesses, display windows, and doorways create natural stopping points
• Transition zones between inside and outside (canopies, arcades, porches) are prime lingering spots
• Avoid large open areas with no edges - people do not stand in the middle of empty spaces
• Score 5: Abundant edge conditions with varied lingering opportunities. Score 3: Some edges activated but large dead zones. Score 1: No comfortable standing/lingering points.

Criterion 6 - Opportunities to Sit Seating is the single most critical element of a successful public space.

• Primary seating (benches): 1 bench per 30m of path, or 1 linear meter of seating per 3 m2 of gathering area, or 1 seat per 10 m2 of total space
• Secondary seating (walls, steps, planters, grass): provide at least as much secondary seating as primary; edges of planters at 40 - 45 cm height function as excellent seats
• Orientation: face sun in cold climates, face shade in hot climates; provide both options where possible; avoid seating facing blank walls
• Social arrangement: mix forward-facing (people-watching), face-to-face (conversation), and right-angle (optional interaction); moveable chairs allow people to self-arrange
• Comfort features: backs and armrests on at least 50% of benches (essential for elderly); bench depth 45 - 50 cm; seat height 40 - 45 cm
• Variety: provide a range from highly social (grouped chairs, cafe tables) to semi-private (single bench with back to hedge) to private (nook, alcove, sheltered corner)
• Views: seating should face activity, people movement, water, greenery, or sky - never a blank wall or parking lot
• Climate: seating in both sun and shade at all times of day; in northern climates, south-facing seating is critical; in hot climates, deep shade is essential
• Score 5: Abundant, varied, comfortable seating with excellent orientation and climate responsiveness. Score 3: Adequate seating but limited variety or poor orientation. Score 1: Insufficient seating, uncomfortable, or poorly placed.

Criterion 7 - Opportunities to See Visibility is essential for feeling safe, engaged, and oriented.

• Clear sightlines of 50 - 100m along main paths and across primary gathering areas
• Lighting must support visibility: even distribution, no dark pockets, appropriate color temperature (2700 - 4000K)
• Remove visual clutter: excessive signage, overgrown vegetation in the 0.6 - 2.0m zone, poorly placed structures
• Frame views to important landmarks, water, sky, or distant greenery
• Provide elevated vantage points (mounds, terraces, viewing platforms) where topography allows
• Score 5: Excellent sightlines, well-lit, views framed beautifully. Score 3: Generally visible but some obstructed views or dark areas. Score 1: Poor visibility, cluttered, dark.

Criterion 8 - Opportunities to Talk and Listen The acoustic environment must support conversation.

• Ambient noise target: < 60 dB in primary gathering and seating areas
• Seating arranged at conversational distances: 0.5 - 1.2m face-to-face, up to 3.0m in group arrangements
• Alcoves, niches, and partially enclosed spaces for intimate conversation
• Hard surfaces can amplify noise - use planting, soft surfaces, and water sounds for acoustic comfort
• Avoid placing seating next to loud mechanical equipment, loading areas, or high-traffic roads
• Score 5: Can easily converse at normal voice everywhere. Score 3: Most areas good but some noisy zones. Score 1: Too noisy to talk comfortably.

Criterion 9 - Opportunities for Play, Exercise, and Activity The space must invite physical engagement for all ages.

• Children (0 - 5): fenced or enclosed play with soft surfacing, sensory elements (sand, water, texture), parental seating with sightlines
• Children (6 - 12): climbing, swinging, sliding, running, imaginative play; challenge and risk appropriate to age; nature play elements (logs, boulders, mounds)
• Teens: basketball/futsal courts, skate features, open lawn for informal games, WiFi and charging, gathering spaces away from adult oversight
• Adults: fitness equipment, jogging/walking loop (min 400m for meaningful exercise), yoga lawn, tai chi area
• Elderly: gentle walking paths (flat, shaded, with frequent benches every 50m), petanque/bocce, tai chi, social seating
• All ages: moveable elements (chairs, hammocks), interactive water features, varied terrain (slopes, mounds), open lawn for unprogrammed activity
• Score 5: Diverse activities for all ages and abilities. Score 3: Some activity options but limited age range or variety. Score 1: No opportunities for active engagement.

ENJOYMENT

Criterion 10 - Scale (Human Scale and Proportion) The space must feel comfortable and appropriately scaled to the human body.

• Building enclosure ratio: surrounding building height should be 1/3 to 1x the width of the space (Sitte proportion)
• Maximum comfortable open dimension before a space feels empty: approximately 100m (unless designed as a grand civic gesture with strong edges)
• Trees provide intermediate scale between buildings and people: use trees at 8 - 15m height to create "rooms" within larger spaces
• Ground plane detail: paving patterns, texture changes, small plantings, furniture - all provide scale at the human eye level (0 - 2m)
• Canopies, pergolas, and arcades at 2.5 - 4.0m create an intimate overhead plane
• Avoid vast, featureless hard surfaces - break them down with trees, furniture, planters, level changes
• Score 5: Feels intimate, comfortable, and human-scaled throughout. Score 3: Generally comfortable but some areas feel oversized or exposed. Score 1: Feels vast, empty, intimidating, or crushing.

Criterion 11 - Opportunities to Enjoy Climate Design the space to maximize climate comfort throughout the year.

• Sun access: in cold and temperate climates, protect south-facing areas from shadow; use deciduous trees to allow winter sun and provide summer shade; orient primary seating toward the sun path
• Shade: in hot climates, deep shade is essential; use tree canopy (target 40 - 60% shade cover), pergolas, shade sails, building overhangs; provide shaded seating, play, and walking routes
• Wind shelter: use buildings, walls, dense planting, or landform to block prevailing cold winds; design sheltered "sun traps" with walls on 2 - 3 sides
• Rain protection: covered areas (min 10% of space) for rain shelter - arcades, gazebos, large canopy trees, covered pavilions
• Seasonal design: design for the "worst" season - if the space works in January (cold climates) or August (hot climates), it will work year-round
• Score 5: Comfortable and inviting in every season. Score 3: Good in spring/autumn, challenging in summer/winter. Score 1: Unusable in one or more seasons.

Criterion 12 - Positive Sensory Experiences (Aesthetic Quality and Delight) The space must be beautiful, interesting, and sensorially rich.

• Art: integrated public art (not placed as an afterthought); murals, sculpture, interactive installations, light art
• Water: fountains, runnels, reflecting pools, streams - water is the single most powerful attractor in public space; visible from 50m, audible from 20m
• Planting: layered, biodiverse, seasonally changing; fragrant species along paths; autumn color; spring blossoms; winter structure
• Materials: high-quality, natural materials where possible (stone, timber, metal, brick); avoid cheap concrete and plastic; materials that age gracefully (patina, weathering)
• Views: frame views to sky, water, landmarks, greenery; terminate vistas with focal points
• Maintenance: design for beauty requires commitment to maintenance - specify maintenance level and budget at design stage
• Score 5: Stunning, sensorially rich, visitors share photos and return often. Score 3: Pleasant but unremarkable. Score 1: Ugly, neglected, or monotonous.

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4. Dimensional Standards

Use these dimensions as design inputs. Deviations are acceptable with justification but should be flagged.

Plaza and Square Dimensions

• Minimum usable plaza dimension: 15m x 15m (Alexander Pattern 61: "Small Public Squares")
• Ideal plaza proportion: width = 1 - 2x the height of surrounding buildings (Camillo Sitte)
• Maximum dimension before a plaza feels empty: ~100m (unless strongly enclosed on all sides)
• Medieval square proportions (highly successful): 20 - 60m across, irregular geometry, enclosed on 3 - 4 sides