Healthy Buildings, Healthy People, Healthier Bottom Line>>>

By INDEX Editorial Team | Based on peer-reviewed research –

A practical, evidence-aware guide for facility leaders who want to improve indoor conditions while measuring what changes for occupants and the organization.

A building can look attractive and efficient on paper and still leave occupants uncomfortable, distracted, or unsure where to report a problem. For facility managers, HR teams, and business leaders, that creates a practical question: how can a healthier indoor environment support people without relying on broad promises about productivity or return on investment?

A useful starting point is to define “healthy building” by the conditions people experience and the systems that maintain them—not by a label, a single sensor reading, or a product purchase. Indoor air quality, temperature, lighting, sound, moisture, cleaning practices, and occupant feedback all matter. The task is to assess the conditions, prioritize manageable changes, and track results over time.

This guide explains criteria for evaluating workplace environments, the evidence behind the business case, and a measured approach to improvement.

Start with criteria—not a certification badge

A certification can provide a framework, but it does not replace checking how a building operates day to day. In a 2024 study comparing matched occupant survey responses from WELL- and LEED-certified offices, satisfaction ratings were higher across many indoor environmental quality measures in the WELL-certified group. The authors also noted important limitations: they could not pinpoint the reasons for the difference, and they could not control for every building or occupant factor. Certification alone therefore cannot guarantee a particular experience in every workplace. [3]

Instead, facility teams can use a criteria-first review. Ask whether the building has:

1. A plan to manage pollutant sources, including cleaning products, maintenance work, furnishings, and renovation activities.
2. Ventilation that is designed, operated, and maintained for the space’s use and occupancy.
3. Appropriate filtration and air-cleaning measures based on the pollutants and conditions involved.
4. Moisture prevention and response procedures for leaks, spills, and damp materials.
5. Comfortable temperature and humidity conditions that are reviewed alongside air quality.
6. Useful lighting and control of glare, particularly in work areas with screens.
7. Attention to acoustics and privacy, which affect how people experience shared workspaces.
8. A way to hear from occupants and act on recurring concerns, rather than treating complaints as isolated anecdotes.

These criteria do not require a major renovation as the first step. They provide a way to identify what is working, what needs investigation, and what can be improved through operations.

Why the indoor environment belongs in business planning

A building is more than an asset to heat, cool, clean, and maintain. It is also where employees spend time doing their work. Indoor conditions can influence comfort, perceived well-being, and the ability to focus. The U.S. Environmental Protection Agency describes indoor air quality as relevant to the health, comfort, well-being, and productivity of building occupants, and identifies sources, ventilation, moisture, and building operation as important factors. [1]

That does not mean every headache, fatigue complaint, or drop in performance is caused by the building. Symptoms can have multiple explanations, and occupant experiences vary. But patterns across time, locations, activities, or building systems can offer useful signals. If several people report similar discomfort in one area, or complaints appear after a renovation or cleaning change, it is reasonable to document the pattern and investigate potential causes.

The business case is strongest when it is specific to the organization. For example, a facility team might examine how often work orders arise from recurring comfort concerns, whether water issues are addressed promptly, how frequently filters are changed, or how staff rate their workspace. Those measures will not prove that one building intervention caused a change in productivity. They can, however, help management understand conditions, set priorities, and evaluate whether an operational change is associated with improvement.

Research has explored links between indoor environmental conditions and workplace outcomes, including cognitive performance and occupant satisfaction. The evidence is not a promise of a fixed financial return for every building. Results depend on the building, intervention, workforce, and how outcomes are measured. A responsible business case should reflect that uncertainty rather than convert broad research findings into a guaranteed ROI.

The practical science: manage sources, ventilation, and filtration

ASHRAE and EPA describe three widely used approaches to improving indoor air quality: source control, ventilation, and air cleaning. It also notes that indoor air quality should be considered in building design and operation, including alongside energy goals. [2]

1. Control sources before adding equipment

Source control means reducing or containing pollutants where they originate. In an office, sources may include renovation materials, furnishings, printing or maintenance activities, cleaning products, pest control, and moisture-damaged materials. EPA recommends considering indoor air quality in purchasing decisions and coordinating renovations to limit occupant exposure. [1]

Practical steps can include scheduling work when fewer people are present, communicating about temporary changes, isolating work areas where appropriate, and reviewing product information before purchasing. For cleaning, ask what the task requires: routine soil removal, degreasing, or disinfection are not interchangeable purposes. Use a disinfectant only when the task or applicable procedure calls for one, and follow the label directions.

2. Confirm that ventilation serves the space

Ventilation needs relate to factors such as occupancy, room use, equipment, and the building’s HVAC design. A space that has changed use or occupancy may need a review of its air delivery and controls. Blocked supply vents or return grilles can also interfere with air distribution.

ASHRAE Standard 62.1-2022 addresses ventilation and acceptable indoor air quality in many nonresidential buildings; Standard 62.2-2022 covers low-rise residential buildings. The appropriate requirements depend on the building type and applicable codes, so facility teams should work with qualified building professionals rather than treating a general article or a single reading as a compliance assessment. [2]

A carbon dioxide monitor can sometimes help identify patterns related to occupancy and ventilation, but it is not a complete measure of indoor air quality. A single reading cannot identify every pollutant or establish that a space is healthy. Consider readings alongside occupancy, HVAC schedules, outdoor conditions, maintenance records, and occupant reports.

3. Maintain filters and consider filtration in context

Filtration can reduce some airborne particles, but its usefulness depends on the filter, system compatibility, maintenance, and the pollutant of concern. Filters that are not appropriate for the system or changed according to an effective maintenance schedule may not deliver the intended result. Some gaseous pollutants require different controls from particle filtration.

Start with the building’s existing equipment and maintenance plan. Ask facilities professionals to confirm filter specifications, fit, replacement schedule, and whether the HVAC system can accommodate a proposed change. Avoid presenting a standalone purifier or a particular technology as a substitute for source control, ventilation, or professional diagnosis.

4. Prevent and respond to moisture problems

Leaks and damp materials can contribute to indoor environmental problems. Identify who receives reports, how leaks are escalated, and how affected areas are inspected and dried. Keep records of water events and repairs, especially if concerns recur in the same location. Investigating the moisture source is more useful than masking odors or relying on routine surface cleaning alone.

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Measure what matters without overstating the result

A credible improvement plan begins with a baseline. Decide what conditions you are trying to improve and what evidence would be meaningful. Depending on the building, teams may review HVAC maintenance records, work orders, occupant feedback, comfort complaints, moisture incidents, and cleaning-product purchasing practices.

Use measures that match the intervention:

• For a ventilation adjustment: document the change, operating conditions, and relevant system information.
• For a cleaning procedure update: record the products and methods used, staff training, and occupant feedback about odor or irritation.
• For a comfort concern: compare reports by time, location, and operating schedule.
• For moisture response: track the time from report to inspection and corrective action.
• For a broader program: repeat an occupant survey with consistent questions and explain how responses will be used.

Where possible, compare results over a relevant period and account for other changes, such as occupancy shifts, seasonal weather, or renovations. Report what the data can show—and what it cannot. For example, a change in survey scores may be encouraging, but it does not by itself establish that a particular building measure caused the change.

The 2024 study of certified office buildings is a useful reminder that occupant experience is multi-dimensional. It found differences in satisfaction between the two matched groups, but the researchers could not isolate the exact cause. In other words, building decisions should be guided by evidence and occupant feedback, while still recognizing the limits of observational comparisons. [3]

Build a shared process between occupants and facility teams

Indoor air quality and comfort often involve shared responsibilities. Building management may control central HVAC operation, while tenants or department leaders influence furnishings, cleaning practices, equipment, and activities in their spaces. EPA recommends coordination between occupants, office managers, and building management, especially where responsibility for the building systems is shared. [1]

A workable process can be straightforward:

• Name a primary contact for indoor environment concerns.
• Provide a clear way to report a concern, including location and time.
• Record recurring reports and maintenance responses.
• Share what is being investigated, while avoiding premature conclusions.
• Involve qualified professionals when a concern requires system inspection, sampling, or health guidance.
• Close the loop with occupants when actions are taken.

This approach can help managers separate isolated discomfort from repeated patterns that deserve investigation. It can also build trust: people are more likely to report issues when they know concerns will be heard, documented, and handled consistently.

Make the business case in terms leaders can evaluate

Healthy building investments do not have a single standard payback calculation. Building owners, tenants, and employers may experience different costs and benefits. A tenant may pay for an improvement while the property owner controls the HVAC system; an employer may value staff experience while the landlord manages the building envelope. Identify who bears the cost, who controls the action, and who may benefit.

For a proposal, show:

• The condition or operational issue: for example, recurring comfort concerns, maintenance gaps, or pollutant sources.
• The proposed response: describe a specific change, not a broad promise.
• The cost and responsibilities: include staff time, equipment, maintenance, and any professional assessment.
• The evaluation plan: define measures and when they will be reviewed.
• The limits: note relevant uncertainties and alternative explanations.

Harvard’s healthy buildings resource illustrates how organizations may model possible operational and workforce effects, but its financial examples rely on stated assumptions and should not be treated as predictions for every workplace. [4] Use organization-specific inputs and conservative assumptions. If the potential benefit is uncertain, say so.

Practical pathways for the first 90 days

A facility team does not need to begin with a full-building retrofit. Consider a staged approach:

Weeks 1–2: Listen and review. Gather existing work orders, occupant concerns, HVAC maintenance schedules, cleaning procedures, and moisture records. Identify repeated patterns and urgent issues.

Weeks 3–4: Choose a focused priority. Select one area where there is a clear concern and a feasible response. Confirm who has authority to make the change and whether specialist input is needed.

Weeks 5–8: Implement and communicate. Put the selected operational change into practice. Tell occupants what is changing, why, and where they can share feedback.

Weeks 9–12: Review and adjust. Compare records and feedback with the baseline. If the desired result is not apparent, revisit the diagnosis rather than assuming a product or equipment purchase will solve the problem.

The appropriate first action may be a maintenance correction, a better reporting process, source reduction, or an assessment by a qualified professional. Let the building’s conditions guide the next step.

Assess your indoor environment

Start with the Healthy Indoor Scorecard. The 25-question assessment helps facility and workplace teams review indoor conditions. Use it to identify areas for follow-up—not as a medical diagnosis, building inspection, or substitute for professional assessment.

A healthier building is an ongoing practice

Healthy buildings are not defined by a single label or purchase. They are supported by thoughtful source control, ventilation, maintenance, moisture response, occupant feedback, and evaluation. For employers and facility teams, the practical opportunity is to connect those operating decisions with the experience of the people who use the building—and to measure progress without promising more than the evidence can support.

INDEX is a 501(c)(3) nonprofit. Our work connects peer-reviewed research in the Science Center with practical pathways through a Science-to-Solution methodology. The aim is to help people and organizations assess indoor exposure questions and make informed decisions.