Public Space Design Skill

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)

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

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.

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

Seating Standards

• 1 linear meter of bench per 3 m2 of primary gathering area
• 1 seat (individual) per 10 m2 of total open space
• Bench spacing along paths: every 30m (general), every 50m (parks/greenways), every 100m (long-distance trails)
• Alternate sun and shade sides of paths for bench placement
• Bench dimensions: seat height 40 - 45 cm, seat depth 45 - 50 cm, back height 40 - 50 cm above seat
• Armrest height: 20 - 25 cm above seat level
• Planter edge seating height: 40 - 45 cm, depth minimum 30 cm

Tree and Canopy Standards

• Target canopy cover over paved areas: 30 - 40%
• Target canopy cover over lawn and park areas: 60 - 80% (at maturity)
• Street tree spacing: 8 - 12m on center (species dependent)
• Park tree spacing: varies by species (5 - 15m)
• Minimum soil volume per tree: 15 - 20 m3 (for trees reaching 10m+ height)
• Tree pit minimum: 1.5m x 1.5m (urban); 2.0m x 2.0m preferred
• Clear trunk height for pedestrian passage: 2.5m minimum

Play Area Standards

• Play area per child in service area (under 12): 2.4 m2
• Fenced play area for under 5s: minimum 100 m2, preferred 200 - 400 m2
• Adventure play for 6 - 12: minimum 300 m2, preferred 500 - 1500 m2
• Safety surfacing fall zones: as per EN 1176/1177 or ASTM F1487/F1292
• Parent seating: sightlines to all play equipment, within 15m, in both sun and shade

Service Radii (Catchment Areas)

• Pocket park: 200m radius (3-minute walk, serving ~500 - 2,000 people)
• Neighborhood park: 500m radius (7-minute walk, serving ~5,000 - 10,000 people)
• District park: 1,500m radius (20-minute walk, serving ~25,000 - 50,000 people)
• City/regional park: 5,000m+ radius (drive, transit, or cycle)

Water Feature Standards

• Water feature visible from: 50m minimum
• Water feature audible from: 20m minimum
• Interactive water play area: minimum 50 m2, drain slope 1 - 2%
• Reflecting pool depth: 10 - 30 cm (shallow for safety and visual effect)
• Fountain spray height: proportional to space - typically 1/3 to 1/2 of adjacent building height (max)

Gradient and Access Standards

• Universal access primary routes: maximum 5% (1:20) gradient, preferred 2% (1:50)
• Cross-slope on paths: maximum 2% for drainage
• Gathering areas and seating zones: maximum 2% slope
• Ramps: max 1:12 (8.3%), with landings every 9m of run; 1:20 preferred where space allows
• Steps: riser 120 - 170 mm, tread 280 - 400 mm; contrasting nosing; handrails both sides

Lighting Standards

• Paths and walkways: 10 - 20 lux average
• Gathering and seating areas: 30 - 50 lux average
• Play areas: 20 - 30 lux (if lit for evening use)
• Feature lighting (art, water, specimen trees): 100+ lux on feature surface
• Uniformity ratio (min/avg): 0.25 minimum, 0.4 preferred
• Color temperature: 2700 - 3000K (warm, inviting) for gathering areas; 4000K for paths where safety is primary
• Mounting height: 3 - 5m for pedestrian areas (human scale); avoid tall highway-style poles

5. Placemaking Principles (PPS Methodology)

Apply Project for Public Spaces methodology in parallel with the Gehl criteria.

The Power of 10+

Every successful public space needs at least 10 things to do. If you cannot list 10 activities or reasons a person would visit, the design is under-programmed.

• List 10+ activities during design review: sit in the sun, eat lunch, watch children play, read, meet a friend, attend a market, exercise, enjoy art, listen to music, walk the dog, people-watch, take a photo...
• Each sub-area of the space should offer at least 3 distinct activities
• A great district has 10+ great places; a great place has 10+ things to do; a great city has 10+ great districts

Triangulation

Position elements to stimulate interaction between strangers.

• Place a bench facing a playground (parents interact while watching children)
• Place a food vendor adjacent to seating and a water feature (people gather, linger, talk)
• Combine art with seating and a view (people stop, look, comment to each other)
• Busker/performer spots positioned where natural pedestrian flows intersect with seating areas
• Interactive elements (musical instruments, game tables, swings) naturally bring strangers together

Edge Activation (Gehl's Edge Effect)

People gravitate to edges, not centers. Activity concentrates where the space meets its boundary.

• Design active edges: ground-floor cafes, shops, market stalls, display windows, entrances along at least 2 sides (ideally 3 - 4) of the space
• Building facades fronting the space should have doors and windows every 5 - 8m (active frontage)
• Edge seating (benches along walls, cafe tables against facades) fills first
• Avoid blank walls, parking garages, or service entrances facing the space
• If a blank wall is unavoidable, activate it with vertical gardens, murals, climbing plants, or temporary markets

Comfort Essentials

People will not stay in a space that lacks basic comfort provisions.

• Seating: abundant and varied (see Criterion 6)
• Shade and shelter: available without walking more than 30m in hot climates
• Food and drink: within 100m (cafe, vendor, food truck); ideally visible and accessible from primary seating
• Restrooms: within 200m; clean, safe, accessible; signage from the space
• Water: drinking fountain within 100m; interactive water for play in summer
• WiFi and power: increasingly expected; design charging stations into furniture

Management and Stewardship

Great spaces are actively managed, not just designed and abandoned.

• Every space needs a steward: parks department, BID, community group, or property manager
• Programming: weekly markets, seasonal festivals, fitness classes, art installations, children's events
• Maintenance: daily cleaning, weekly furniture check, monthly planting care, seasonal deep clean
• Observation and adaptation: conduct annual public life studies (see references/gehl-criteria.md) to measure use and adjust

6. Anti-Patterns (Common Public Space Design Mistakes)

Flag and avoid these in every design review:

1. The Empty Plaza - vast hard surface with no seating, shade, or reason to stop. Fix: add trees, seating, program, edges.
2. The Fortress Park - fenced on all sides with limited entry points, invisible from the street. Fix: open edges, multiple entrances aligned with pedestrian flows.
3. The Hostile Bench - seating designed to prevent sleeping (divided seats, armrests every 50 cm, sloped surfaces). Fix: design for comfort first; address homelessness with social services, not hostile architecture.
4. The Windswept Corridor - tall buildings create wind-tunnel effects in the public space at their base. Fix: wind analysis during design, sheltering elements, vegetation.
5. The Dead Edge - space bordered by blank walls, parking garages, or inactive uses. Fix: activate edges with retail, food, community uses, or at minimum with art and planting.
6. The Car Park Compromise - surface parking occupies the best waterfront, civic, or central land. Fix: relocate parking below grade or to the periphery.
7. The Over-Designed Space - so heavily designed and controlled that spontaneous use is impossible. Fix: leave 30 - 40% of the space as open, flexible, unprogrammed lawn or paving.
8. The Maintenance Fantasy - elaborate water features, exotic planting, and delicate materials with no maintenance budget. Fix: design to the actual maintenance budget; specify robust materials and low-maintenance planting.
9. The Sunless Square - primary gathering space placed in permanent building shadow. Fix: model sun/shadow; locate gathering space to receive minimum 4 hours of direct sun in equinox.
10. The Inaccessible Gem - beautiful space that cannot be reached easily on foot or by transit. Fix: connect to the pedestrian network; ensure entries from all surrounding streets.

7. Output Template

When presenting a public space design, structure the output as follows:

[Space Name]: [Typology] Design

Site Summary

• Location: [address/coordinates]
• Area: [ha / m2]
• Typology: [from Section 1]
• Service radius and estimated catchment population: [from Section 4]
• Key site constraints: [sun, wind, noise, access, topography]

Design Concept

• [1 - 2 paragraph narrative describing the vision, spatial character, and experience]
• Primary spatial structure: [rooms, axes, focal points]

Program

Dimensional Compliance

Gehl 12 Criteria Scorecard

Placemaking Check

• Power of 10+: [list 10+ reasons to visit]
• Triangulation: [describe key triangulation moments]
• Edge activation: [describe active edges and dead edges mitigated]
• Comfort essentials: seating, shade, food, restrooms, water, WiFi

Materials and Planting

• Primary paving: [material, color, finish, source]
• Secondary paving: [material]
• Furniture: [bench type, bollard, bin, light]
• Planting palette: [canopy trees, understory, groundcover, seasonal highlights]
• Water feature: [type, size, sound character]

Maintenance and Management

• Estimated annual maintenance cost: [$/m2/year based on typology]
• Management responsibility: [entity]
• Key seasonal programming: [events/activities by season]

8. Reference Links

Use the following references for detailed guidance:

• Space typologies and precedents: See references/space-typologies.md for 10+ typologies with dimensional ranges, materials, planting, and precedent examples.
• Gehl 12 criteria scoring: See references/gehl-criteria.md for the full scoring methodology, observation tools, and data collection templates.
• Programming by user group: See references/programming-guide.md for activity programming, seasonal strategies, event infrastructure, and maintenance benchmarks.

Key External References:

• Jan Gehl, "Cities for People" (2010) and "Life Between Buildings" (1971)
• Project for Public Spaces, "How to Turn a Place Around" (2000)
• Christopher Alexander, "A Pattern Language" (1977), Patterns 61, 106, 119, 120, 121, 171, 172
• Gehl Institute, Public Life Tools: publiclifetools.org
• William H. Whyte, "The Social Life of Small Urban Spaces" (1980)
• Clare Cooper Marcus & Carolyn Francis, "People Places" (1997)
• Camillo Sitte, "City Planning According to Artistic Principles" (1889)
• NACTO Urban Street Design Guide (for streetscape integration)
• UN-Habitat Global Public Space Toolkit (2015)
• Trust for Public Land ParkScore methodology