What Open-Plan Offices Reveal About Employee Experience
September 2026
There’s a conversation happening in HR and operations right now that didn’t exist ten years ago.
It’s about the built environment. Specifically, about the growing evidence that the physical conditions inside offices- temperature, lighting, glare, acoustic separation. These have a measurable effect on employee engagement, concentration, and satisfaction. And that some of the most significant drivers of that effect come through glass.
This isn’t speculative. It’s published research from occupational science, building performance, and environmental psychology. And September (when Q3 closes, year-end planning begins, and the return-to-office pattern has settled into its fall rhythm) is when this conversation tends to become actionable.
The open-plan office became the dominant commercial design aesthetic of the 2010s for clear reasons. Transparency, collaboration, natural light, reduced construction costs. The design philosophy was earnest and not without merit.
What the research has also consistently found is that open-plan environments create specific challenges that affect the employees inside them, and that thermal discomfort and visual glare consistently appear in the list of most-cited problems.
A 2021 systematic review published in SAGE Open examining psychological and work outcomes in open-plan vs. cellular office designs found that environmental characteristics of particular concern included lighting, glare, and poor temperature control alongside noise and privacy concerns. These weren’t fringe findings; they were consistent across studies, representing the persistent objections that open-plan occupants raise when surveyed about their working conditions.
Research published in Frontiers in Built Environment in 2026 examining open-plan office performance indicators identifies thermal comfort as having a significant impact on worker productivity, health, and satisfaction, and notes specifically that poor thermal comfort, including overheating, makes it difficult to concentrate and increases absenteeism.
These aren’t soft observations. They’re measurable, replicated outcomes.
The glass problem inside open-plan offices is specific.
Modern commercial open-plan spaces typically feature either floor-to-ceiling exterior glazing, interior glass partitions, or both. The exterior glazing was chosen for natural light, a genuine benefit supported by research. A controlled crossover study published in ScienceDirect found that access to daylight and a view in an office improves cognitive performance and satisfaction while reducing eyestrain compared to windowless environments.
But uncontrolled daylight is not the same as natural light. The research on open-plan retrofits makes this distinction precisely. A 2025 study published in ScienceDirect, examining passive retrofit optimizations for open-plan offices, found that without solar heat and glare control, Energy Use Intensity and occupant discomfort both remain elevated. The same study found that implementing shading controls with appropriate Solar Heat Gain Coefficients improved thermal comfort percentages by more than 200% in summer and nearly 150% in winter, while reducing energy use intensity by 26 to 31% and 65 to 82%, respectively.
The mechanism is straightforward. Floor-to-ceiling glazing facing south or west generates solar heat gain that creates temperature differentials across the open floor plate. Employees near window walls experience warmer conditions than those at interior positions. The HVAC system, designed for the average load of the space rather than the peak thermal load at the perimeter, cannot fully compensate.
The result is exactly what facility managers and HR professionals hear in complaints: “It’s too hot over here.” “The glare makes it impossible to see my screen after 2 PM.” “I can’t work at this desk on sunny afternoons.”
These complaints aren’t about preference. They’re documented environmental stressors with measurable effects on concentration and task performance.
Why this matters now, in September.
Returning to the office in autumn brings a specific dynamic that summer remote work patterns often obscure. Employees who tolerated an uncomfortable desk position in May or June, before taking July and August more remotely, are returning in September to the same position, the same glare, the same afternoon heat differential.
September also brings a new solar variable: the sun’s angle is dropping. As discussed in building science literature, lower solar elevation angles increase penetration depth into interior spaces. In wintertime, the sun will be at a lower angle, resulting in high solar penetration into a structure with substantial sunshine and brightness on south and east orientations from at least 10 AM to 2 PM. This means south- and east-facing desks that were partially shaded by high summer sun are now receiving more direct low-angle glare, precisely as employees are returning to five-day office schedules.
It’s a collision of calendar and physics that facilities teams haven’t always accounted for.
The employee experience framing that’s changing the conversation.
For the past several years, the corporate real estate and facilities management industries have been absorbing a shift in how the office is justified. The case for bringing employees back isn’t made on efficiency metrics alone; it’s increasingly made on the quality of the in-person experience relative to working from home.
A home office, whatever its limitations, allows the occupant to control their thermal environment. They can move away from a window, adjust a blind, or they can change rooms. The return-to-office ask, particularly in a labor market where talent has leverage, requires that the office environment offer something better than what employees have at home. Or at minimum, something not measurably worse.
An office where west-facing desks become uncomfortable for three hours every afternoon, where screen glare drives employees to work in dim corners, where temperature differentials across the floor plate create persistent complaints, is making a case for itself that facilities teams may not intend.
The research is direct here. A ScienceDirect review of office environmental factors and satisfaction found that temperatures below or above the 20 to 24°C comfort range and lighting conditions that create glare decrease productivity, concentration, and mood while increasing fatigue and stress. These are the conditions that erode the case for physical presence, one uncomfortable afternoon at a time.
The intervention that addresses the source, not the symptom.
Facilities teams have a limited toolkit for managing solar heat gain and glare in open-plan environments with existing glass:
Closing interior blinds addresses the visual problem but eliminates the natural light that the space was designed to provide. HVAC adjustments manage average temperature but cannot overcome the differential between window-adjacent and interior positions. Desk reconfigurations work around the problem rather than solving it, and limit the flexibility that open-plan design is supposed to provide.
Solar control window film applied to exterior glazing addresses the source directly. By reducing the Solar Heat Gain Coefficient of existing glass, from roughly 0.70 to 0.75 down to 0.25 to 0.40 depending on film specification, it reduces the incoming thermal load that creates perimeter hot zones while maintaining the visible light transmission that makes the space feel open and connected to the exterior.
Glare is addressed simultaneously. The same film that reduces infrared radiation also reduces the harsh visible light intensity that washes out screens and creates eye strain during peak sun hours, without the darkness that closed blinds create.
The result, supported by the retrofit research cited above, is a more consistent thermal environment across the floor plate, reduced afternoon glare complaints, maintained natural light, and measurably lower energy consumption from reduced HVAC peak loads.
One thing worth checking before this goes live: the 0.70-0.75 to 0.25-0.40 SHGC range reads like a general window film industry figure, not something pulled from the ScienceDirect study you cited earlier in the piece. If a reader assumes that number is sourced from the same study, that’s a misattribution problem. Worth confirming where it actually comes from.
The business case framing.
For decision-makers evaluating this as an operational investment rather than a building upgrade, the relevant variables are:
Employee complaints and HR engagement with comfort issues: a measurable administrative cost that scales with headcount and complaint frequency.
Space utilization: whether certain desks, zones, or collaborative areas are being avoided during peak solar hours, reducing the effective usable capacity of the space.
Energy costs: particularly peak demand charges driven by afternoon HVAC loads competing against solar heat gain.
Retention and recruitment context: whether the office environment is an asset or a liability in the employee experience conversation.
None of these require fabricated case studies to make the case. The research on open-plan environmental comfort, the energy performance data on glazing retrofits, and the straightforward logic of addressing heat and glare at their source, the glass, provides the foundation.
That last sentence has a subject-verb agreement problem: “research… data… and… logic… provides” should be “provide” (plural subject, three items joined by “and”). Fixed it below if you want it clean:
None of these require fabricated case studies to make the case. The research on open-plan environmental comfort, the energy performance data on glazing retrofits, and the straightforward logic of addressing heat and glare at their source, the glass, provide the foundation.
The open-plan office was designed to support a certain kind of work culture. The physics of uncontrolled glass works against it every afternoon the sun shines on the west facade.
Addressing that gap is a facilities decision. The business case for making it has been getting stronger all year.
Evaluate Your Office’s Solar Performance
CoolVu works with commercial facilities teams to assess solar heat gain patterns across floor plates, identify the glazing exposures creating the most significant comfort and energy problems, and specify solar control film solutions matched to each orientation.
Find your local CoolVu installer: www.coolvu.com
Your office should make the case for itself. Uncomfortable afternoons don’t help.
