Sustainability Quick Reference
This cheat sheet covers sustainability topics tested across multiple ARE 5.0 divisions, especially PA and PDD. See the Sustainable Design topic guide for comprehensive study.
LEED v4.1 Credit Categories
| Category | Points Available | Key Credits |
|---|
| Integrative Process | 1 | Early analysis of energy and water systems |
| Location & Transportation | 16 | Site selection, transit access, bicycle facilities, parking reduction |
| Sustainable Sites | 10 | Site assessment, open space, rainwater management, heat island, light pollution |
| Water Efficiency | 11 | Indoor water use, outdoor water use, cooling tower water, water metering |
| Energy & Atmosphere | 33 | Energy performance, renewable energy, commissioning, refrigerant management |
| Materials & Resources | 13 | LCA, EPDs, sourcing of raw materials, material ingredients, C&D waste |
| Indoor Environmental Quality | 16 | Ventilation, low-emitting materials, thermal comfort, daylighting, views |
| Innovation | 6 | Innovative strategies, LEED AP |
| Regional Priority | 4 | Location-specific credits |
Certification levels: Certified (40–49), Silver (50–59), Gold (60–79), Platinum (80+) out of 110 points.
Passive Solar Design Strategies
| Strategy | Application | Key Details |
|---|
| Building orientation | Long axis east-west | Maximizes south-facing glazing for solar gain in winter |
| South glazing | Most glazing on south facade | Easy to shade with horizontal overhangs; winter sun low angle |
| Overhangs | South-facing horizontal shading | Block high summer sun; admit low winter sun |
| Thermal mass | Concrete, masonry, tile floors | Absorbs heat during day; radiates at night |
| Cross ventilation | Operable windows on opposite walls | Inlet area ≤ outlet area for best airflow |
| Stack ventilation | High exhaust openings | Hot air rises; draws cooler air in from below |
| Earth sheltering | Berming, underground spaces | Stable ground temperature (~55°F) reduces heating/cooling load |
| Light shelves | Horizontal reflective surface at window | Bounces daylight deeper into space; shades lower glazing |
Daylighting Metrics
| Metric | Description | Target |
|---|
| Spatial Daylight Autonomy (sDA) | % of floor area receiving ≥30 fc for ≥50% of occupied hours | ≥55% for LEED credit |
| Annual Sunlight Exposure (ASE) | % of floor area receiving ≥1000 lux for ≥250 hrs/yr | ≤10% (limits glare) |
| Daylight Factor | Ratio of interior to exterior illuminance (%) | 2–5% typical target |
| Useful Daylight Illuminance (UDI) | Hours between 100–2000 lux | Higher is better |
| Daylight zone depth | Rule of thumb | 1.5–2.0 × head height of window |
Energy Code Compliance (ASHRAE 90.1 / IECC)
| Compliance Path | Description |
|---|
| Prescriptive | Meet individual requirements for each component (envelope, lighting, HVAC) |
| Trade-off (envelope only) | COMcheck: trade between envelope components (more insulation = more glass) |
| Performance (whole building) | Energy model shows proposed building uses ≤ energy of baseline building |
Key ASHRAE 90.1 requirements:
- Lighting power density (LPD) limits by space type
- Minimum equipment efficiency (SEER, EER, COP)
- Envelope U-factor and SHGC by climate zone
- Economizer requirements based on cooling capacity and climate
- Energy recovery required above certain OA thresholds
Water Conservation Fixtures
| Fixture | Federal Baseline (EPAct) | WaterSense / LEED Target |
|---|
| Water closet (toilet) | 1.6 gpf | 1.28 gpf (HET) or 1.1 gpf (dual flush) |
| Urinal | 1.0 gpf | 0.5 gpf or waterless |
| Lavatory faucet (public) | 0.5 gpm | 0.35 gpm (metering) or 0.5 gpm |
| Lavatory faucet (private) | 2.2 gpm | 1.5 gpm |
| Kitchen faucet | 2.2 gpm | 1.8 gpm |
| Showerhead | 2.5 gpm | 2.0 gpm or less |
Sustainable Material Strategies
- Recycled content: Post-consumer (used by end user) vs pre-consumer (manufacturing waste)
- Regional materials: Extracted and manufactured within 500 miles (LEED v2.2) or by cost (v4)
- Rapidly renewable: Harvest cycle ≤10 years (bamboo, cork, wool, cotton)
- FSC-certified wood: Sustainably harvested (Forest Stewardship Council)
- EPDs (Environmental Product Declarations): Third-party verified LCA data for products
- HPDs (Health Product Declarations): Disclose chemical ingredients and health hazards
- Low-emitting materials: Low VOC paints, adhesives, sealants, carpet per CDPH Standard Method v1.2
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