InterNACHI Well cheat sheet

WELL v2 organizes requirements into 10 concepts: Air, Water, Nourishment, Light, Movement, Thermal Comfort, Sound, Materials, Mind, and Community.

Each concept contains features; each feature contains parts scored as Preconditions (mandatory) or Optimizations (points toward certification).

WELL v2 scoring: every feature part is worth up to 10 points; total available points are normalized so the maximum achievable score equals 100.

Certification tiers by total score: WELL Bronze 40, Silver 50, Gold 60, Platinum 80 points (v2 thresholds).

Preconditions must all be met before any certification tier is awarded; Optimizations accumulate points.

WELL v2 has four project types: New and Existing Buildings, New and Existing Interiors, Core and Shell, and Communities (WELL v2 pilot-era structure).

Performance verification is conducted by a WELL Assessor on site after documentation review and is required for building certification.

Recertification is required on a cycle (typically every 3 years in v2) to maintain an active certification.

The WELL AP credential is earned by passing an exam and maintained through continuing education; the standard is administered by the International WELL Building Institute (IWBI).

Ventilation effectiveness depends on outdoor air rate, distribution, and system balance; ASHRAE 62.1 provides minimum outdoor air rates by occupancy.

Filtration rating: MERV 13 or higher is commonly specified for particulate removal; MERV 13 captures a substantial fraction of PM2.5 and larger particles.

PM2.5 refers to particles with aerodynamic diameter 2.5 micrometers or less; PM10 refers to 10 micrometers or less.

Carbon dioxide is used as a proxy for ventilation adequacy; outdoor CO2 is roughly 400-420 ppm and indoor targets are often set below 800-1000 ppm.

TVOC sensors measure total volatile organic compounds; they are non-specific and are used for trend monitoring rather than compound identification.

Source control hierarchy: eliminate or isolate the source, then ventilate, then filter; filtration does not substitute for source removal.

Ozone (O3) and formaldehyde (CH2O) are common indoor pollutants targeted by WELL Air features; formaldehyde is a known carcinogen.

Air quality testing is typically performed after construction and before occupancy, with the building flushed out and HVAC running.

Common drinking-water contaminants of concern include lead, arsenic, nitrate, disinfection byproducts (trihalomethanes), and turbidity.

Lead enters drinking water primarily through corrosion of plumbing and solder; corrosion control (pH and alkalinity adjustment) is the primary mitigation.

Point-of-use filtration (carbon block, reverse osmosis) can reduce many contaminants; RO removes dissolved ions but wastes reject water.

Water testing should sample at the point of use and include both first-draw and flushed samples to distinguish stagnation effects.

Legionella risk is managed by maintaining hot water temperatures (typically stored above 60 C and delivered above 50 C at outlets) and avoiding dead legs.

Water access features address drinking water availability, bottle fillers, and promotion of water over sugar-sweetened beverages.

Turbidity is a proxy for particulate and microbial contamination; low turbidity supports effective disinfection.

Total coliform and E. coli are indicator organisms for microbiological contamination of drinking water.

Thermal comfort is predicted by ASHRAE 55 and ISO 7730 using operative temperature, humidity, air speed, clothing insulation (clo), and metabolic rate (met).

PMV (Predicted Mean Vote) ranges from -3 (cold) to +3 (hot); acceptable comfort is typically -0.5 to +0.5 with PPD at or below 10%.

Radiant temperature asymmetry and draft are common causes of local discomfort even when PMV is acceptable.

Sound levels are commonly specified in dBA; background noise targets for open offices are often around 35-45 dBA.

Reverberation time (RT60) measures how long sound persists; excessive RT60 reduces speech privacy and increases listening effort.

Sound Transmission Class (STC) rates partition performance; higher STC means less airborne sound transmission.

Noise Criteria (NC) and Room Criteria (RC) curves are used to specify acceptable background noise spectra.

Acoustic comfort features address HVAC noise, sound insulation between spaces, and absorption in open areas.

Illuminance is measured in lux (lm/m2); typical office task lighting targets are around 300-500 lux at the work plane.

Daylight autonomy (DA) is the percentage of occupied hours when a space meets a target illuminance from daylight alone; common targets are 50-75%.

Spatial Daylight Autonomy (sDA) and Annual Sunlight Exposure (ASE) are climate-based daylight metrics; ASE limits glare risk.

Correlated color temperature (CCT) describes the color appearance of light; higher CCT (e.g., 5000 K) appears cooler/bluer.

Melanopic equivalent daylight illuminance (melanopic EDI) quantifies the circadian-effective light dose on the eye.

Circadian entrainment depends on light timing, intensity, spectrum (blue-rich light is more effective), and duration.

Glare metrics include Daylight Glare Probability (DGP) and Unified Glare Rating (UGR); UGR below about 19 is often targeted for offices.

Color rendering is measured by CRI (Ra) or TM-30 (Rf and Rg); high fidelity rendering supports visual comfort and task performance.

Nourishment features address availability of fruits and vegetables, limits on processed foods, and nutritional transparency (calorie and ingredient labeling).

Food environment strategies include placement and visibility (choice architecture), pricing, and vending standards.

Movement features promote stair use, active commuting (bike storage, showers), and physical activity spaces.

Stair promotion often uses signage, visibility, and aesthetic improvements; stair use is a low-cost way to increase daily activity.

Point-of-decision prompts are environmental cues placed at the moment of choice (e.g., elevator vs. stairs) and are evidence-based behavior-change tools.

Movement features may include treadmill desks, standing-height workstations, and walking paths or fitness rooms.

Nutrition standards often reference dietary guidelines: increased whole foods, limited added sugar, sodium, and saturated fat.

Breastfeeding support (lactation rooms) is a Nourishment/Community-related feature in many healthy building frameworks.

Mind features address mental health promotion, stress reduction, sleep support, and access to nature (biophilia).

Biophilic design elements include natural light, views of nature, plants, natural materials, and patterns that evoke nature.

Community features address occupant engagement, social connection, and access to health-promoting amenities.

Occupant surveys (e.g., satisfaction or wellbeing surveys) are common tools for evaluating perceived comfort and mental health.

Health promotion programs and workplace policies (flexible schedules, quiet spaces, restorative areas) support mental wellbeing.

Noise, thermal discomfort, and lack of control over the environment are recognized stressors in indoor environments.

Access to daylight and views is associated with improved mood and reduced stress in office settings.

Emergency preparedness and occupant communication are part of community resilience in healthy building frameworks.

VOC content (g/L) is a formulation metric; emission testing (e.g., chamber testing) measures what is released into indoor air over time.

Low-VOC content does not guarantee low emissions; both content and emissions should be evaluated.

Common certifications: GREENGUARD Gold, CDPH Standard Method (Section 01350), and Cradle to Cradle for material health.

Formaldehyde is a common indoor pollutant from pressed wood products, some insulation, and combustion; it is classified as a human carcinogen.

Material ingredient transparency tools include Health Product Declarations (HPDs) and Declare labels.

Red List chemicals (Living Building Challenge) and similar hazard lists identify substances to avoid in building products.

Wet-applied products (paints, adhesives, sealants) are major VOC sources during and after construction; allow adequate flush-out time.

Resilient flooring, carpet, and composite wood are common targets for low-emission specifications.

Performance verification combines documentation review, on-site inspection, and spot testing by a WELL Assessor.

Air testing typically measures PM2.5, PM10, TVOC, formaldehyde, and CO; results are compared to feature thresholds.

Water testing typically measures turbidity, coliforms, lead, arsenic, and disinfection byproducts at points of use.

Acoustic testing may include background noise level, reverberation time, and sound insulation measurements.

Lighting verification includes illuminance measurements at the work plane and review of daylight metrics from simulation.

Thermal comfort verification uses spot measurements of temperature, humidity, and air speed, plus review of PMV/PPD calculations.

Sampling plans must specify location, timing, instrument calibration, and detection limits to be defensible.

Documentation should include test reports, calibration certificates, and photographs that link measurements to specific spaces.

The WELL project submission process includes documentation review, performance verification, and final reporting to IWBI.

Documentation should be organized by feature and part, with clear cross-references to drawings, specifications, and test reports.

Test reports should include methodology, instrument calibration, sample locations, results, and comparison to thresholds.

Performance verification reports document on-site findings and any deficiencies that require corrective action.

Recertification requires demonstrating continued compliance, often through updated testing and documentation.

Version control and dated records support auditability; retain records for the certification cycle.

Common documentation gaps include missing calibration records, incomplete sampling maps, and lack of occupancy schedules.

Project teams often use a compliance matrix tracking each feature part, responsible party, evidence, and status.