# Resilient Design

## Resilience Overview

### Definition
Resilient design creates buildings and communities that can withstand, adapt to, and rapidly recover from disruptions including natural disasters, climate change impacts, and infrastructure failures.

### Resilience Framework
| Phase | Goal |
|-------|------|
| Prepare | Reduce vulnerability |
| Withstand | Survive the event |
| Recover | Return to function |
| Adapt | Improve for future |

### Hazard Categories
| Category | Examples |
|----------|----------|
| Climate | Heat, drought, precipitation |
| Weather | Hurricane, tornado, flood |
| Geologic | Earthquake, landslide |
| Fire | Wildfire, urban fire |
| Infrastructure | Power outage, water loss |
| Human | Pandemic, civil unrest |

---

## Climate Adaptation

### Heat Resilience
| Strategy | Implementation |
|----------|----------------|
| Cool roofs | SRI ≥ 78 (low-slope), ≥ 29 (steep) |
| Cool pavements | Light colors, permeable |
| Shade structures | Trees, canopies, arcades |
| Natural ventilation | Operable windows, stack effect |
| Thermal mass | Concrete, masonry |
| Insulation | Exceed code minimums |

### Heat Island Mitigation
| Surface | Strategy |
|---------|----------|
| Roofs | Cool roof, green roof, solar |
| Parking | Trees, light pavement, shade |
| Hardscape | Light colors, permeable |
| Landscape | Maximize tree canopy |

### Passive Survivability
| Standard | Duration |
|----------|----------|
| Maintain habitability | 7 days without power |
| Temperature range | 54-86°F indoor |
| Basic functions | Water, sanitation, shelter |
| Communication | Battery/solar charging |

### Passive Cooling Strategies
| Strategy | Effectiveness |
|----------|---------------|
| Cross-ventilation | 3-5°F reduction |
| Night flush cooling | 5-10°F reduction |
| Thermal mass | Moderate swings |
| Earth coupling | Stable temperatures |
| Evaporative cooling | Dry climates only |

---

## Flood Resilience

### Flood Zone Classifications
| Zone | Description | Requirements |
|------|-------------|--------------|
| VE | Coastal high hazard | Elevated, breakaway walls |
| AE | Base flood w/ BFE | Elevated or floodproofed |
| AO | Sheet flow | Elevated above depth |
| X (shaded) | 500-year | Consider protection |
| X (unshaded) | Minimal flood | Standard construction |

### Elevation Strategies
| Approach | Application |
|----------|-------------|
| Fill | Raise entire site |
| Foundation walls | Crawlspace above BFE |
| Piers/piles | Coastal, deep flood |
| Stilts | V-zone required |
| Living shoreline | Coastal buffer |

### Freeboard
| Jurisdiction | Above BFE |
|--------------|-----------|
| NFIP minimum | 0" |
| Recommended | +1' to +2' |
| ASCE 24 (critical) | +2' to +3' |
| Sea level rise | +1' to +3' additional |

### Flood-Resistant Materials
| Zone | Requirement |
|------|-------------|
| Below BFE | Class 4-5 flood damage resistant |
| Utilities | Elevated or submersible |
| Insulation | Closed-cell only |
| Flooring | Concrete, tile, vinyl |
| Walls | CMU, pressure-treated, fiber cement |

### Floodproofing Types
| Type | Description | Limitations |
|------|-------------|-------------|
| Dry | Watertight barriers | ≤ 3' depth |
| Wet | Allow flooding, resistant materials | Non-residential |
| Temporary | Deployable barriers | Requires warning time |

---

## Wind Resilience

### Wind Speed Design
| Category | 3-second Gust | Damage |
|----------|---------------|--------|
| Cat 1 | 74-95 mph | Minimal |
| Cat 2 | 96-110 mph | Moderate |
| Cat 3 | 111-129 mph | Extensive |
| Cat 4 | 130-156 mph | Extreme |
| Cat 5 | 157+ mph | Catastrophic |

### Enhanced Wind Design
| Component | Strategy |
|-----------|----------|
| Roof | Hip roof, slope 4:12-6:12 |
| Connections | Hurricane straps, clips |
| Sheathing | 8d nails @ 4" OC |
| Openings | Impact-rated or shutters |
| Garage doors | Wind-rated, braced |
| Soffits | Wind-resistant, vented |

### Continuous Load Path
| Connection | Hardware |
|------------|----------|
| Roof to wall | Hurricane clips |
| Wall to wall | Strap ties |
| Wall to foundation | Anchor bolts, holddowns |
| Shear walls | Holdowns, anchor bolts |

### Opening Protection
| Option | Protection Level |
|--------|------------------|
| Impact-rated glazing | Missile D (large) |
| Hurricane shutters | Various ratings |
| Plywood (temporary) | Minimal protection |
| Storm panels | Reusable, storable |
| Roll-down shutters | Convenient, expensive |

---

## Seismic Resilience

### Seismic Design Categories
| SDC | Description | Requirements |
|-----|-------------|--------------|
| A | Very low | Basic |
| B | Low | Some detailing |
| C | Moderate | Seismic detailing |
| D | High | Full seismic design |
| E | Very high (near fault) | Enhanced design |
| F | Critical facilities in D/E | Most stringent |

### Structural Systems
| System | Ductility | Application |
|--------|-----------|-------------|
| Special moment frame | High | Flexible buildings |
| Special shear wall | High | Stiff buildings |
| Braced frame | Moderate | Industrial |
| Base isolation | Very high | Critical facilities |
| Damping systems | Very high | High-rise, critical |

### Non-Structural Elements
| Element | Anchorage Required |
|---------|-------------------|
| MEP equipment | Seismic bracing |
| Ceilings | Compression struts |
| Partitions | Top of wall bracing |
| Cladding | Flexible connections |
| Contents | Anchored furniture |

### Performance Objectives
| Level | Damage | Downtime |
|-------|--------|----------|
| Immediate occupancy | Minimal | Hours |
| Life safety | Moderate | Weeks |
| Collapse prevention | Severe | Months/write-off |

---

## Fire Resilience (Wildfire)

### Wildfire Zones
| Zone | Distance | Treatment |
|------|----------|-----------|
| Zone 0 | 0-5' | Non-combustible |
| Zone 1 | 5-30' | Fire-resistant, lean |
| Zone 2 | 30-100' | Reduced fuels |
| Zone 3 | 100-200' | Managed vegetation |

### Ignition-Resistant Construction
| Component | Strategy |
|-----------|----------|
| Roofing | Class A (metal, tile, composite) |
| Walls | Non-combustible, 6" above grade |
| Vents | 1/8" mesh, ember-resistant |
| Eaves | Enclosed, non-combustible |
| Decks | Non-combustible or ignition-resistant |
| Windows | Multi-pane, tempered |

### Defensible Space
| Element | Treatment |
|---------|-----------|
| Vegetation | Spacing, low-flammability species |
| Mulch | Non-combustible within 5' |
| Fencing | Non-combustible within 5' |
| Storage | No combustibles against building |
| Trees | Limbed up, spaced crowns |

### WUI Codes
| Code | Application |
|------|-------------|
| IWUIC | International WUI Code |
| California (Ch. 7A) | State standard |
| Local overlays | Added requirements |

---

## Power Resilience

### Backup Power Options
| Type | Runtime | Maintenance |
|------|---------|-------------|
| Portable generator | Hours | Fuel storage |
| Standby generator | Days | Weekly test |
| Solar + storage | Variable | Minimal |
| Fuel cell | Days | Fuel supply |
| Microgrids | Indefinite | Complex |

### Critical Loads
| Load | Priority |
|------|----------|
| Life safety | 1 (required) |
| HVAC (critical areas) | 2 |
| Refrigeration | 3 |
| Lighting | 4 |
| Communications | 5 |
| Other | 6 |

### Generator Sizing
| Method | Approach |
|--------|----------|
| Full backup | All loads |
| Partial backup | Critical only |
| Load shedding | Managed switching |
| Islanding | Microgrid operation |

### Solar + Storage Sizing
| Objective | Sizing Approach |
|-----------|-----------------|
| Grid resilience | Critical loads × hours |
| Daily cycling | Peak shaving |
| Full backup | Days of autonomy |

---

## Water Resilience

### Water Supply Alternatives
| Source | Application |
|--------|-------------|
| Municipal backup | Dual connections |
| On-site well | Backup supply |
| Rainwater harvesting | Non-potable, emergency |
| Storage tanks | Short-term backup |
| Water recycling | Reduce demand |

### Emergency Water Storage
| Use | Gallons per Person per Day |
|-----|---------------------------|
| Survival minimum | 1 gallon |
| Adequate | 3-5 gallons |
| Comfort | 50+ gallons |

### Greywater Systems
| Source | Reuse |
|--------|-------|
| Lavatory | Toilet flushing |
| Shower | Irrigation |
| Laundry | Irrigation |
| Kitchen | Not recommended |

### Rainwater Harvesting
| Element | Sizing |
|---------|--------|
| Cistern | 1" rain × roof SF × 0.6 |
| First flush | 10 gallons per 1,000 SF |
| Treatment | UV, filtration for potable |

---

## Community Resilience

### Resilience Hubs
| Function | Provision |
|----------|-----------|
| Shelter | Space for displaced residents |
| Power | Solar + storage for charging |
| Water | Potable water supply |
| Communication | WiFi, cell charging |
| Services | Food distribution, first aid |

### Multi-Hazard Shelters
| Hazard | Design Feature |
|--------|----------------|
| Hurricane | Wind-rated envelope |
| Tornado | Safe room (FEMA 361) |
| Earthquake | Seismically designed |
| Flood | Elevated or elevated access |

### Community Facilities
| Facility | Resilience Role |
|----------|-----------------|
| Schools | Shelter, voting, recovery |
| Libraries | Information, cooling |
| Recreation centers | Shelter, services |
| Fire stations | Emergency services |
| Community centers | Gathering, distribution |

---

## Certification Programs

### RELi
| Category | Focus |
|----------|-------|
| Panoramic approach | Hazard assessment |
| Hazard preparedness | Specific hazards |
| Hazard adaptation | Long-term change |
| Community cohesion | Social resilience |

### FORTIFIED
| Level | Protection |
|-------|------------|
| Bronze | Roof |
| Silver | Roof + openings |
| Gold | Full envelope |

### LEED Resilience Credits
| Credit | Points |
|--------|--------|
| Assessment and planning | 1 |
| Design for resilience | 1 |
| Passive survivability | 1 |

---

## Documentation

### Hazard Assessment
| Component | Content |
|-----------|---------|
| Site hazards | All applicable risks |
| Historical events | Past disasters |
| Future projections | Climate change |
| Vulnerability | Building weaknesses |
| Consequences | Impact of failures |

### Resilience Plan
| Section | Content |
|---------|---------|
| Design strategies | How hazards addressed |
| Operational procedures | Emergency operations |
| Recovery plan | Return to function |
| Maintenance | Ongoing requirements |

### Building Manual
| Content | Purpose |
|---------|---------|
| Emergency procedures | Occupant actions |
| System operations | Backup system use |
| Contact information | Emergency contacts |
| Supplies inventory | Emergency supplies |
