Energy Efficiency in Small Commercial Buildings
Commercial buildings consume roughly 12 percent of all U.S. energy, and most of that energy is wasted through poor scheduling, inadequate controls, and systems running as if nothing inside the building has changed since the day they were commissioned. This guide explains where energy goes in small commercial buildings, what monitoring reveals about waste, and which improvements deliver the fastest payback.
How Much Energy Small Commercial Buildings Waste
Energy efficiency in commercial buildings is not primarily a technology problem. It is an information problem. Building owners make decisions about HVAC schedules, setpoints, and equipment based on how they believe the building operates, rather than how it actually does. The gap between those two things is where energy is lost.
Research from Pacific Northwest National Laboratory, prepared for the U.S. Department of Energy, found that commercial buildings across the United States could reduce annual energy consumption by up to 29 percent through better controls alone, without replacing any mechanical equipment.[1] The savings come from fixing how existing equipment is operated. For most small commercial buildings, that means two things: knowing what the building is actually doing, and having the ability to adjust schedules and setpoints based on that knowledge.
Most of the available energy savings in commercial buildings do not require capital investment. They require operational changes driven by real data: adjusting how existing equipment runs based on actual conditions, not on assumptions that may not have been revisited in years.
How a Commercial Building Uses Energy
Understanding where energy goes in a commercial building is the first step toward reducing it. Most building owners track total utility costs but cannot connect those costs to specific systems or behaviors. Submetering and monitoring change that picture entirely.
HVAC Systems
Heating, ventilation, and air conditioning typically accounts for 40 to 50 percent of commercial building energy consumption. It is also where the largest operational savings are available, because HVAC systems in most small buildings run on fixed schedules that do not reflect actual occupancy or conditions.
Lighting
Lighting represents 20 to 30 percent of energy use in most commercial buildings. Buildings without occupancy sensing often illuminate unoccupied spaces for hours. LED upgrades are well-known, but lighting schedules and occupancy-based control are frequently overlooked and deliver significant savings without any fixture replacement.
Plug Loads and Equipment
Computers, servers, kitchen equipment, and other plug loads account for 20 to 30 percent of commercial energy use and are growing as a share of total consumption. Many of these loads operate 24 hours a day without any schedule or control, drawing standby power through nights, weekends, and holidays.
Domestic Hot Water
In buildings with kitchens, laundry, or high-use restrooms, domestic hot water can represent 5 to 15 percent of total energy use. Setpoint drift, circulation pump inefficiency, and lack of scheduling for water heaters are common sources of waste that monitoring and controls can address.
Building Envelope Losses
Heat transfer through walls, windows, roofs, and air infiltration at doors and penetrations can account for 10 to 20 percent of conditioning load. Sensor data reveals envelope performance problems that are otherwise invisible: a zone that consistently runs hotter than the rest of the building on cold days, or one that cannot hold temperature on sunny afternoons.
Unoccupied Hours
Energy consumed while a building is unoccupied is pure waste. In many small commercial buildings, HVAC systems run on schedules that do not reflect actual use patterns: conditioning spaces on weekends, during holidays, or for hours before and after the workday when no one is present. Monitoring reveals the actual occupancy window.
Why Do Small Commercial Buildings Struggle With Energy Efficiency?
Small commercial buildings face a compounded energy challenge. They tend to be older, they tend to have simpler (or no) controls, and they tend to lack the staff and systems that would reveal how much energy they are wasting.
The median commercial building in the United States is 36 years old, and 75 percent of the existing building stock was built more than 25 years ago, before modern building automation became widely available.[3] These buildings were designed and constructed with the HVAC controls technology of their era: pneumatic thermostats, fixed-schedule timers, and no means of measuring what was actually happening inside the building. Many have never been retrofitted with even basic digital controls.
The result is a large population of buildings operating on assumptions that may have been outdated for decades. HVAC schedules set during initial commissioning and never adjusted. Setpoints calibrated for an occupancy pattern that changed when the tenant mix changed. Ventilation rates designed for a building use that no longer applies. None of this is visible without continuous monitoring.
Less than 10 Percent Use Available Tools
Research on the small commercial building market found that fewer than 10 percent of small building owners use available energy benchmarking tools, and fewer than 40 percent are aware of the efficiency and demand response incentive programs available in their utility territory.[4] The barriers are not primarily financial. They are informational: owners do not know what their buildings are doing, do not know what good performance looks like, and have no baseline against which to measure improvement.
This is the core argument for monitoring before investment. A building that has never been measured cannot be optimized. And a building whose energy use has been measured and understood can often find 15 to 20 percent savings through operational changes alone, before spending a dollar on equipment.
Where Do the Energy Savings Actually Come From?
The PNNL analysis of commercial building energy savings potential identified the specific control measures that deliver the largest reductions. All of them are operational. None require replacing mechanical equipment. What they all require is accurate data about how the building is actually performing.
| Control Measure | Energy Savings Potential | What the Data Reveals |
|---|---|---|
| Wider temperature deadbands and night setbacks | 7.8% | How far the building drifts from setpoint during unoccupied hours; how much conditioning it takes to recover |
| Shortened HVAC operating schedules | 7.1% | Actual occupancy start and end times versus programmed schedule; energy consumed conditioning an empty building |
| CO2-based demand control ventilation | 7.1% | Real-time CO2 concentrations that reveal over-ventilation during low occupancy and under-ventilation during peaks |
| Optimal start and stop | 5.9% | How long it takes the building to reach setpoint from setback; whether pre-conditioning starts too early or too late |
| VAV system damper adjustments | 3.1% | Zone-level airflow imbalances; dampers that are stuck open or delivering more air than the zone requires |
These five measures together represent approximately 31 percent of total energy consumption in a typical commercial building, well above the 29 percent headline figure because some measures interact and compound each other.[1] The key insight is that the first step toward each of these improvements is not a contractor or an equipment purchase. It is a dataset: continuous, zone-level temperature, CO2, and occupancy data showing what the building actually does.
Schools and Retail Have the Highest Potential
The PNNL research found significant variation in savings potential by building type. Schools show the highest opportunity at 48.8 percent, followed by retail at 40.8 percent.[1] These building types share a common characteristic: highly variable occupancy patterns that their HVAC systems are not designed to track. A school building is fully occupied five days a week and nearly empty on nights and weekends. A retail building may see peak occupancy for only a few hours of the day. HVAC systems running fixed schedules in either building type are almost certainly conditioning spaces when no one is there.
For more on how these savings opportunities apply to specific building types, see the vertical guides on this site, including dedicated pages for schools and office buildings.
How to Know If Your Building Is Performing Well or Poorly
Energy efficiency is a relative measure. A building that uses 80 kBtu per square foot per year may be highly efficient for one building type and deeply wasteful for another. The standard unit for comparing commercial building energy performance is Energy Use Intensity (EUI), expressed in kBtu per square foot per year. It normalizes consumption for building size, making comparison meaningful across a portfolio or against national benchmarks.
The U.S. Energy Information Administration’s Commercial Buildings Energy Consumption Survey (CBECS) publishes median EUI figures by building type. These serve as the national baseline against which any commercial building can measure itself.[2]
| Building Type | Median EUI (kBtu/sq ft/yr) | Primary Energy Driver |
|---|---|---|
| K-12 Schools | 48 | HVAC (heavily variable occupancy) |
| Office Buildings | 68 | HVAC and lighting, plug loads growing |
| Retail / Mercantile | 71 | HVAC, lighting (often high-intensity) |
| Food Service | 247 | Cooking equipment, refrigeration, HVAC |
| Warehouse / Storage | 31 | Lighting, minimal HVAC |
| Healthcare (Outpatient) | 124 | HVAC (stringent IAQ), plug loads |
A building significantly above its peer median has identifiable reasons for that gap, and most of those reasons are diagnosable from sensor data. A school running at 70 kBtu/sq ft/yr instead of the national median of 48 has a 46 percent efficiency gap. That gap has a cause. It might be HVAC equipment running during unoccupied hours. It might be setpoints that are too aggressive in heating mode. It might be ventilation that over-delivers during low-occupancy periods. Finding the cause requires data, not guesswork.
ENERGY STAR Portfolio Manager is the standard free tool for tracking and benchmarking commercial building energy use. It allows building owners to compare their EUI against national medians and to document efficiency improvements over time. Monitoring data from sensors feeds directly into that analysis.
What Does Monitoring Reveal About Energy Waste?
There is a consistent pattern in buildings that undergo their first continuous monitoring deployment. The problems that are found are rarely the problems that were expected. A building owner who believed the HVAC was undersized discovers instead that it is oversized and running far longer than it needs to because setpoints are too aggressive. A building thought to have a failing chiller turns out to have a scheduling problem that causes it to operate at full load during hours of minimal occupancy.
This is the fundamental argument for a data-first approach to energy efficiency: the diagnosis should precede the prescription. Specifying equipment upgrades before understanding how existing equipment performs is the most common and most expensive mistake in commercial building energy management. The capital cost of an unnecessary equipment replacement dwarfs any operational savings it might have produced.
Establish a baseline with 60 to 90 days of continuous monitoring
A baseline dataset covering a full billing period across at least one typical week of operation reveals patterns that no amount of observation or estimate can capture: how the building behaves overnight, how it responds to outdoor temperature swings, and how different zones compare to each other under the same conditions.
Identify the largest gaps between actual and expected performance
Compare your building’s EUI against CBECS medians for your building type. Compare zone temperatures against setpoints to find chronic over-heating or over-cooling. Compare HVAC runtime against occupancy schedules to find the hours when the system is conditioning space no one is using. These gaps are where the savings are.
Make operational changes and confirm their effect
Adjusting a setback schedule or widening a deadband is a change that takes minutes. Confirming that it worked, and quantifying how much it saved, requires data before and after the change. Continuous monitoring makes this confirmation automatic. Without it, you are managing by assumption.
Use the data to guide capital decisions
Once operational savings are captured, the remaining efficiency gap can be evaluated honestly. A building that has been monitored for a year and has optimized its operational performance knows what its equipment can and cannot do. Capital investment decisions made from that position are far more reliable than those made without any baseline. For a detailed look at how equipment costs compare against monitoring-first alternatives, see BAS Cost Breakdown.
For an overview of how building automation systems monitor and control energy use at scale, and why most small buildings cannot access that technology directly, see the full BAS explainer.
More Resources on Building Energy Efficiency
Energy efficiency intersects with indoor air quality, HVAC controls, and building-type-specific challenges. These guides provide more depth on the topics that matter most for small commercial building operators.
Indoor Air Quality
How ventilation, CO2, and humidity management connect to both occupant health and HVAC energy consumption.
Building Automation Systems
How a full BAS manages energy at scale, what it costs, and why 87 percent of small commercial buildings operate without one.
What Is a Fractional BAS?
The monitoring-first approach that delivers energy data and operational insight for buildings that cannot afford full automation.
Compliance and Standards
NYC Local Law 97, federal sustainability requirements, and state benchmarking laws that make energy efficiency a compliance issue for many buildings.
BAS Cost Breakdown
A realistic look at what a full building automation system costs versus what monitoring-first alternatives deliver for a fraction of the investment.
Small Building Statistics
Data and research on the U.S. small commercial building stock: size, age, energy use, and the scale of the efficiency opportunity.
Research and Data Sources
All statistics and research findings cited in this article are drawn from primary government and academic sources.
- Pacific Northwest National Laboratory. Energy Savings Potential and RD&D Opportunities for Commercial Building HVAC Systems. PNNL-25985. Prepared for the U.S. Department of Energy, May 2017. pnnl.gov
- U.S. Energy Information Administration. 2018 Commercial Buildings Energy Consumption Survey (CBECS). Energy Characteristics and Energy Consumed in Large Commercial Buildings table series. eia.gov
- The Real Estate Roundtable. Commercial Real Estate by the Numbers: 2023. Analysis of U.S. commercial real estate stock by building age and size.
- James Dice, Nexus Labs and Keyframe Capital. The Untapped 87%: A Framework for Understanding Why Small Commercial Buildings Lack Building Automation. 2021.
Find Out Where Your Building Is Wasting Energy
Nosy is a fractional BAS that delivers continuous temperature, CO2, humidity, and environmental monitoring across every zone of your building, giving you the data to find and fix energy waste without guesswork.