What is WELL, LEED and BREEAM? – Which (important) role plays air quality in this?

WELL, LEED, and BREEAM are three prominent certification systems that focus on sustainability and environmental performance in the built environment. Each of these systems has its unique approach and criteria, but they share a common goal of promoting more sustainable and healthier buildings.


The WELL Building Standard, developed by the International WELL Building Institute (IWBI), is a certification system that primarily focuses on the health and well-being of building occupants. It encompasses various aspects of human health, including air quality, lighting, water quality, nutrition, fitness, mental well-being and others. WELL certification provides guidelines and performance metrics for architects, designers, and building owners to create spaces that prioritize the physical and psychological well-being of the people who use them.

WELL certification is organized into several categories, such as air, water, nourishment, light, fitness, and comfort, with specific features and performance requirements within each category. These include factors like access to natural light, air filtration, ergonomic design, and the promotion of physical activity within the building.

2. LEED:

The Leadership in Energy and Environmental Design (LEED) system, developed by the U.S. Green Building Council (USGBC), is a globally recognized green building certification program. LEED takes a holistic approach to sustainability, considering various factors like energy efficiency, water conservation, materials selection, and indoor environmental quality.

LEED certification offers different levels of recognition based on the number of points a building earns across various sustainability categories. These categories include Sustainable Sites, Water Efficiency, Energy and Atmosphere, Materials and Resources, Indoor Environmental Quality, and Innovation in Design.

LEED promotes sustainable construction practices, encourages resource efficiency, and prioritizes the reduction of a building’s environmental impact. It has become a benchmark for green building design and construction worldwide


The Building Research Establishment Environmental Assessment Method (BREEAM) is a certification system developed in the United Kingdom but now used internationally. BREEAM evaluates the environmental sustainability of buildings and infrastructure projects. Like LEED, BREEAM covers a wide range of sustainability criteria, including energy and water efficiency, materials selection, and indoor environmental quality.

BREEAM uses a points-based system to assess and certify buildings, and it includes categories such as Management, Health and Well-being, Energy, Transport, Water, Materials, Waste, Land Use and Ecology, and Pollution. Building projects earn credits within these categories to achieve a BREEAM rating, ranging from “Pass” to “Outstanding.”

BREEAM has been instrumental in promoting sustainable building practices in Europe and beyond, and it emphasizes aspects like site ecology, adaptability to climate change, and post-construction performance monitoring.

In summary, WELL, LEED, and BREEAM are three leading certification systems in the field of sustainable and environmentally friendly building design and construction. WELL focuses on occupant health and well-being, LEED takes a comprehensive approach to sustainability, and BREEAM provides a holistic assessment of a building’s environmental impact. Each system contributes to the global effort to create more sustainable and healthier built environments.

Which (important) role plays air quality in the certification systems WELL, LEED and BREEAM?

Air quality plays a significant role in the certification systems of WELL, LEED, and BREEAM, as it directly impacts the health, comfort, and well-being of building occupants. Each certification system addresses air quality in its own way:

1. WELL:

Air quality is a fundamental aspect of the WELL Building Standard. WELL places a strong emphasis on ensuring clean and healthy indoor air for occupants. The Air category in WELL focuses on several key factors, including:

a. Air Quality Standards: WELL sets strict criteria for indoor air quality, including limits on pollutants such as volatile organic compounds (VOCs), particulate matter, carbon monoxide, and ozone. It also requires regular testing to ensure compliance.

b. Ventilation: WELL encourages adequate ventilation rates and the use of high-efficiency air filtration systems to remove airborne contaminants and allergens.

c. Tobacco Smoke Control: Smoking is typically prohibited within and around WELL-certified buildings to prevent exposure to secondhand smoke.

d. Materials and Furnishings: WELL promotes the use of low-emission building materials, finishes, and furnishings to minimize the release of harmful chemicals into the indoor air.

2. LEED:

LEED considers indoor environmental quality (IEQ) as one of its key categories, and air quality is a crucial component of this category. LEED encourages measures to enhance indoor air quality, such as:

a. Ventilation: LEED requires buildings to provide proper ventilation systems to ensure a steady supply of fresh outdoor air. This helps dilute indoor pollutants and improve overall air quality.

b. Low-Emitting Materials: LEED awards points for the use of low-VOC and low-emission materials, paints, adhesives, and sealants to reduce indoor air pollution.

c. Tobacco Smoke Control: Similar to WELL, LEED typically restricts smoking in and around certified buildings to prevent secondhand smoke exposure.


BREEAM also addresses indoor air quality within its assessment criteria. The Health and Well-being category in BREEAM includes considerations for air quality, such as:

a. Ventilation Rates: BREEAM encourages buildings to provide effective ventilation systems to ensure an adequate supply of fresh air for occupants.

b. Monitoring and Control: BREEAM may require the installation of air quality monitoring systems to maintain acceptable indoor air quality levels.

c. Low-Emitting Materials: Like LEED, BREEAM promotes the use of low-VOC and low-emission materials to reduce indoor air pollution.

d. Tobacco Smoke Control: BREEAM typically restricts smoking in and around certified buildings to protect occupants from secondhand smoke.

In summary, all three certification systems, WELL, LEED, and BREEAM, recognize the importance of indoor air quality and include specific criteria to ensure that building occupants have access to clean and healthy indoor air. These criteria encompass ventilation, pollutant control, and the use of low-emission materials, contributing to the overall well-being and comfort of building occupants while also supporting sustainability goals.

Are you planning a certification, or do you need air quality analyses for your current certification process?
We are at your disposal with our test methods.

We sample formaldehyde and VOCs according to ISO 16000-2 and ISO 16000-5. After, the samples get analysed in an accredited laboratory according to ISO 16000-3 and ISO 16000-6.

Particulate matter PM2.5 and PM10 we test with an optical particle counter OPC according to ISO 16000-34.