A Guide to WELL Performance Testing

To create healthier and more sustainable built environments, the WELL Building Standard has emerged as a groundbreaking framework that prioritizes the well-being of occupants. WELL Performance Testing is crucial in guaranteeing that the building adheres to the rigorous standards outlined by the International WELL Building Institute. It also verifies that health and well-being strategies, grounded in evidence, have been executed and are functioning according to the plan. This article delves into the significance of WELL Performance Testing, its key components, and the benefits it brings to both occupants and the environment.

Understanding the WELL Building Standard:

The WELL Building Standard is a performance-based system for measuring, certifying, and monitoring features of the built environment that impact human health and well-being. Developed by the International WELL Building Institute (IWBI), it focuses on ten core concepts: Air, Water, Nourishment, Light, Movement, Thermal Comfort, Sound, Materials, Mind, and Community. WELL Performance Testing evaluates a building’s compliance with these concepts, comprehensively assessing its impact on the occupants.

Performance Verification entails collecting on-site measurements, either through a site visit by a WELL Performance Testing Agent who conducts performance tests or through permanently installed continuous monitors, followed by a Performance Review by a WELL Reviewer assigned by IWBI. Collecting on-site measurement data is a requirement for WELL Certification and the WELL Performance Rating, and the results of the data collected for each applicable feature are reviewed by the WELL Reviewer to determine whether a feature has been achieved. 


All features and underlying parts marked as preconditions must be met to achieve a given concept. Preconditions define the fundamental components of a WELL-certified space and serve as the foundation of people’s first places. WELL V2 offers a universal set of preconditions for all projects. 


Many features include optimizations that projects may elect to pursue to meet certification requirements. All optimizations are weighted with varying point values. The maximum point value of a feature is determined by the sum of its parts. A part is weighted by its potential for impact, defined as the extent to which a feature addresses a specific health concern or opportunity for health promotion and the potential impact of the intervention.

Key Components of WELL Performance Testing:

Air Quality Testing:

WELL Performance Testing rigorously measures the indoor air quality, ensuring that pollutants are maintained within acceptable limits. It evaluates ventilation systems, guaranteeing the delivery of fresh and clean air to occupants. Additionally, the testing process monitors the presence of volatile organic compounds (VOCs) and other harmful substances, promoting a healthier indoor environment.

The following Air Concept features will be verified during the Performance Testing:

A01. Air Quality (Precondition)

This WELL feature requires projects to provide acceptable air quality levels, as determined by public health authorities.

A05. Enhanced Air Quality (Optimization)

This WELL feature requires projects to go beyond current guidelines to provide enhanced air quality levels that have been linked to improved human health and performance.

Verification during Performance Testing considers the following parameters:

  • PM2.5 and PM10
  • Formaldehyde and Acetaldehyde
  • VOCs (other than Formaldehyde and Acetaldehyde)
  • Carbon monoxide
  • Ozone
  • Nitrogen dioxide
  • Radon

Water Quality Testing:

This component assesses the quality of drinking water to ensure it is free from contaminants, safeguarding the health of building occupants. WELL Performance Testing also examines water purification systems and plumbing to prevent waterborne illnesses. Furthermore, it encourages the use of sustainable water sources and efficient water management practices.

The following Water Concept features will be verified during the Performance Testing: 

W01. Water Quality Indicators (Precondition)

This WELL feature requires the provision of water that meets thresholds for turbidity and coliforms for all water likely to come in contact with building occupants and verifies performance using on-site tests.

W02. Drinking Water Quality (Precondition)

This WELL feature requires projects to provide drinking water that meets thresholds on chemicals as published by research and regulatory organizations.

W04. Enhanced Water Quality (Optimization)

This WELL feature requires projects to provide drinking water that meets thresholds on chemicals that affect aesthetics and taste concerns.

Verification during Performance Testing includes the following parameters: 

  • Turbidity
  • Coliforms
  • Disinfectants
  • Lead
  • Laboratory-based Contaminants (except Lead)

Lighting Assessments:

Focusing on the lighting quality within a building promotes visual comfort and reduces eye strain. It measures natural light exposure to support circadian rhythms and enhances sleep quality. Additionally, the testing process encourages the implementation of energy-efficient lighting systems, contributing to both occupant well-being and environmental sustainability.

The following Light Concept features will be verified during the Performance Testing:

L01. Light Exposure (Precondition)

This WELL feature requires projects to provide appropriate light exposure in indoor environments through lighting strategies.

L02. Visual Lighting Design (Precondition)

This WELL feature requires projects to provide appropriate illuminances on work planes for regular users of all age groups, as required for the tasks performed in the space.

L03. Circadian Lighting Design (Optimization)

This WELL feature requires projects to provide users with appropriate exposure to light for maintaining circadian health and aligning the circadian rhythm with the day-night cycle.

Verification during Performance Testing includes the following parameters:

  • Visual Lighting
  • Circadian Lighting

Thermal Comfort Evaluations:

WELL Performance Testing addresses thermal comfort to prevent discomfort and health issues related to temperature. Moreover, it promotes acoustical comfort to reduce noise-related stress and improve concentration in indoor environments.

The following Thermal Comfort Concept features will be verified during the Performance Testing:

T01. Thermal Performance (Precondition)

This WELL feature requires projects to create indoor thermal environments that provide comfortable situational conditions to the majority of people in support of their health, well-being, and productivity.

T07. Humidity Control (Optimization)

This WELL feature requires projects to maintain optimum relative humidity levels that are conducive to human health and well-being.

Verification during Performance Testing includes the following parameters:

  • Dry-bulb Temperature
  • Mean Radiant Temperature
  • Relative Humidity

Sound Levels Verification:

By evaluating maximum noise levels, sound barriers, and reverberation time, WELL Performance Testing ensures that the building’s acoustic environment promotes occupant well-being and productivity. Excessive noise levels can cause stress, fatigue, and reduced productivity, while inadequate sound barriers and high reverberation times can result in poor speech intelligibility, making communication difficult. By addressing these issues, the testing process promotes a healthier and more comfortable acoustic environment, reducing the risk of hearing damage and improving communication and concentration.

The following Sound Concept features will be verified during the Performance Testing:

S02. Maximum Noise Levels (Optimization)

This WELL feature prescribes maximum thresholds for ambient background noise that correspond to optimal levels of interior and exterior noise exposure.

S03. Sound Barriers (Optimization)

This WELL feature requires that walls and doors meet a minimum degree of acoustical separation to provide adequate sound isolation and improve speech privacy.

S04. Reverberation Time (Optimization)

This WELL feature requires that steps be taken to address acoustical comfort by controlling reverberation time based on room functionality.

Verification during Performance Testing includes the following parameters:

  • Exterior Noise Intrusion (dBA)
  • Internally Generated Noise (NC or NR)
  • Disruptive Noise Limitation 
  • Background Noise Levels
  • Sound Masking
  • Reverberation Time (RT60)

Benefits of WELL Certification:

  1. Occupant Well-being:

    WELL Certification contributes to creating environments that enhance building occupants’ physical and mental health. By addressing factors such as air quality, water quality, lighting, and comfort, the testing process reduces the risk of illnesses related to poor indoor environmental conditions.

  2. Increased Productivity:

    Results from the testing will support productivity by providing comfortable and healthy workspaces. The testing process fosters employee satisfaction and engagement by prioritizing occupant well-being, contributing to overall productivity and a positive work environment.

  3. Environmental Sustainability:

    The test encourages the adoption of sustainable practices in building design and operations. By minimizing resource consumption and reducing environmental impact, buildings undergoing this testing process contribute to broader sustainability goals.

  4. Market Differentiation:

    Buildings that achieve WELL certification through rigorous performance testing gain a competitive edge in the real estate market. This not only attracts tenants and investors but also establishes the building as a desirable and forward-thinking asset in the marketplace, setting it apart from conventional structures.

WELL Performance Testing is a crucial step in creating buildings that prioritize the health and well-being of occupants. By addressing key components such as air quality, water quality, lighting, fitness, nourishment, and mindfulness, this testing process ensures that buildings adhere to the rigorous standards set by the WELL Building Standard. The result is not only healthier and more productive spaces but also a positive impact on the environment. As the demand for sustainable and well-designed buildings continues to grow, WELL Performance Testing becomes an essential tool in creating a built environment that truly prioritizes the well-being of its users.

Want to learn more about getting WELL certified in the easiest and most cost-effective way possible? Read more about how we at Alpin can help you here.