WELL Building Standard

Buildings are no longer evaluated solely by their energy consumption. The new international WELL standard measures something more complex — the quality of the environment for the people who live and work in it. And air is the first and most important criterion of this standard.

Where WELL Came From — The Story Behind the Standard

In the early 2010s, the construction industry was dominated by a single approach to building design: reducing energy consumption and lowering CO₂ emissions.

At that time, standards such as LEED (Leadership in Energy and Environmental Design), BREEAM (Building Research Establishment Environmental Assessment Method), and DGNB (German Sustainable Building Council) were rapidly gaining traction. These systems evaluated buildings primarily as technical systems — in terms of resources, materials, and environmental impact. Yet one crucial question remained largely overlooked: how do people actually feel inside these buildings?

LEED, BREEAM, and DGNB all evaluated buildings as technical systems. But no one was asking: how do people actually feel inside them?

At the same time, American entrepreneur and investor Paul Scialla set out to close this gap. In 2013, as part of the Clinton Global Initiative, his company Delos founded the International WELL Building Institute — a non-profit organization built around a simple idea: buildings should actively improve people’s health, not merely avoid harming it.

In 2014, following a two-year pilot program and an independent scientific review, the first public version — WELL v1 — was released. The standard was immediately certified by Green Business Certification Inc., the same organization that administers LEED. This gave the market confidence in WELL from day one.

In 2020, International WELL Building Institute released WELL v2 — a significantly expanded version of the standard featuring stricter criteria, feedback from thousands of projects worldwide, and a broader range of building typologies.

Who Regulates the Standard and How

WELL is neither a government regulation nor an EU directive. It is a voluntary market standard governed by three independent organizations:

International WELL Building Institute — develops and updates the standard’s requirements, and provides training and certification for professionals (WELL AP).

Green Business Certification Inc. — carries out independent third-party certification of projects. It reviews documentation and organizes on-site performance testing.

Independent auditors (WELL Assessors) — accredited professionals who conduct audits directly on-site.

The certification is valid for three years, after which the project must undergo recertification. This is a fundamental difference between WELL and most building standards, where certification is typically granted once and retained indefinitely.

The 7+3 Concepts: What the Standard Actually Evaluates

WELL v2 evaluates buildings across 10 categories. Each category includes mandatory preconditions and optional optimizations that earn points:

Air

Focused on indoor air quality: minimizing pollutants, ensuring proper ventilation, and controlling harmful substances so people can breathe safely and comfortably.

Water

Focused on access to clean and safe water: monitoring drinking water quality, water supply systems, and hygiene standards.

Nourishment

Focused on healthy eating habits: access to nutritious food, transparency of ingredients, and encouraging better dietary choices.

Light

Focused on lighting that supports vision and circadian rhythms: sufficient daylight and well-designed artificial lighting for comfort and productivity.

Movement

Focused on encouraging physical activity: spaces should naturally motivate people to move more through stairs, convenient pathways, and an active environment.

Thermal Comfort

Focused on comfortable temperature and humidity levels: ensuring people feel neither too cold nor too hot in different areas of the building.

Sound

Focused on noise control and acoustic quality to support concentration, relaxation, and overall comfort.

Materials

Focused on material safety: minimizing toxic substances in furniture, finishes, and construction materials.

Mind

Focused on psychological well-being: reducing stress while supporting focus, emotional balance, and overall wellness.

Community

Focused on human interaction: creating environments that support communication, inclusivity, and a sense of belonging.

Based on the number of points earned, a project receives one of the following certification levels: Bronze / Silver / Gold / Platinum.

Why Air Is the First and Most Important Concept

The Air concept in WELL is far more than just «ventilation.» It is a comprehensive set of requirements that governs:

minimum fresh air supply rates (measured in cubic meters per person per hour);
maximum allowable concentrations: CO₂ (carbon dioxide) — the gas we exhale, an indicator of indoor stuffiness and ventilation performance, PM2.5 (fine particulate matter ≤2.5 μm) — the most dangerous particles, penetrating the lungs and bloodstream, PM10 (particulate matter ≤10 μm) — larger dust particles affecting the respiratory system, TVOC (total volatile organic compounds) — emissions from furniture, paints, plastics, and household chemicals, NO₂ (nitrogen dioxide) — generated by traffic and gas stoves; irritates the lungs, Ozone (O₃) — a gas that protects against UV radiation outdoors but is toxic indoors;
air filtration requirements (MERV/ISO filter classes);
humidity control (40–60% as the optimal range);
restrictions on certain chemical substances in building materials and furniture;
real-time indoor air quality monitoring.

This is where heat recovery becomes not just an option, but a tool for meeting the standard’s requirements.

Ventilation systems with heat recovery provide continuous and controlled air exchange — exactly what WELL requires. Opening a window twice a day does not solve this problem: it does not control airflow volume, filter incoming air, or monitor CO₂ levels.

Scale and Growth: From 6 Projects to 5 Billion Square Feet

WELL Growth in Numbers:

2014 — the standard is launched. The first 6 certified projects.
2016 — more than 200 projects across 21 countries.
2020 — release of WELL v2, expanding the standard to new building typologies.
2024 — more than 5 billion square feet of WELL projects across 130+ countries, serving around 25 million occupants and users.

Today, more than 71 Fortune 500 companies have either achieved WELL certification or are pursuing it. WELL is no longer a niche «green» feature — it has become a competitive advantage in the real estate market.

How a Project Achieves WELL Certification: 5 Steps

Registration: the project team registers on the International WELL Building Institute platform, selects the building type, and pays a registration fee (from $1,500 to $10,000 depending on the type and size of the project).
Documentation: a package of documents is prepared, including technical specifications, plans, data on materials, ventilation systems, and lighting systems.
On-site performance verification: an accredited WELL Assessor visits the project no earlier than one month after occupancy to conduct measurements and a visual inspection.
Occupant survey: for buildings with more than 10 occupants, a survey on user satisfaction and environmental quality is mandatory.
Certification level assignment: based on the number of points earned, the project receives a Silver, Gold, or Platinum rating. The certification remains valid for three years.

WELL in Ukraine: Where We Are Today and Where We’re Heading

In Ukraine, WELL certification is still relatively rare. According to the official WELL registry, there are currently only four WELL projects in the country — a clear indication that the market is only beginning to take shape and still has significant room for growth.

However, the trend is clear. Post-war reconstruction and new construction are taking place under strict energy-efficiency requirements: Ukraine has committed to bringing all new buildings in line with the nZEB (nearly zero-energy buildings) standard by 2027. In this context, WELL becomes the logical next step — moving from an «efficient building» to a «healthy building.»

For architects and designers, this is already a strategic advantage. Premium-segment clients and international developers are increasingly asking about WELL. A specialist who understands the standard and knows how to integrate it effectively into a project becomes a leader in the field.

WELL vs LEED: What’s the Difference?

This raises a very logical question: why do we need WELL if LEED already exists? The answer lies in the different focus of the two standards:

LEED focuses on the building as an engineering and environmental system. It evaluates how efficiently resources such as energy, water, and materials are used, as well as how the building integrates into its surroundings through factors like location, transportation access, and environmental impact. LEED is about reducing operational costs and minimizing a building’s environmental footprint throughout its entire life cycle. In other words, LEED answers the question: how efficient and sustainable is this building as an asset?
WELL, on the other hand, focuses not on the building itself, but on the people inside it — on how the space affects health, well-being, and productivity. It evaluates air quality, water quality, lighting, acoustics, thermal comfort, and even factors such as stress, sleep, and behavioral habits. WELL answers a different question: how does this building affect the people who live or work inside it?

The key difference is simple: LEED is about building performance, while WELL is about quality of life inside the building.

They do not compete with each other — they complement one another.

International WELL Building Institute — the international organization responsible for developing and implementing the WELL standard.

U.S. Green Building Council — the U.S. organization that created the LEED standard.

International WELL Building Institute and U.S. Green Building Council have even developed a streamlined pathway for achieving both LEED and WELL certifications simultaneously. In practice, this is important because a building may be energy-efficient (LEED) while still having poor indoor air quality or inadequate lighting — and these are exactly the issues WELL is designed to address.

The Role of Ventilation in WELL Compliance

The Air concept in WELL is built around measurable metrics and technical requirements rather than general recommendations. In particular:

Indoor CO₂ levels should not exceed 800–1000 ppm — above this threshold, concentration and productivity begin to decline.
The concentration of volatile organic compounds (TVOC) is limited by strict thresholds for each category of substances.
Air exchange rates are calculated based on the type of space and the number of occupants.
Filtration standards require at least MERV-13 filters for most building types.

Heat recovery ventilation systems — such as PRANA — provide exactly this kind of organized and controlled air exchange without heat loss. This not only supports WELL compliance, but also reduces operational costs for heating and air conditioning.

What Does This Mean for Your Project?

WELL is not a bureaucratic certification for the sake of certification itself. It is a structured answer to the question: «How does a building affect the people inside it?»

For architects and designers, this means:

considering air quality, lighting, and acoustics from the very concept stage rather than trying to fix them later;
understanding which building materials comply with VOC requirements and which do not;
being able to explain to clients the difference between a «beautiful building» and a «building that supports health»;
being prepared for requests from developers operating in the international market.

Would you like to learn how PRANA ventilation solutions help meet the requirements of the WELL Air concept in your projects? Contact our technical department for a consultation.

Sources and References:

IWBI — International WELL Building Institute;
WELL Building Standard (Wikipedia);
GBCI — Green Business Certification Inc;
IEA — Energy Efficiency in Ukraine;
WELL Air Concept.