Learn · Smart retrofits and energy savings

What is a retrofit?

A retrofit is any upgrade to an existing building that makes it perform better, usually by using less energy, running more comfortably, or producing fewer emissions. It can be as simple as swapping light fixtures or as involved as replacing a heating system and re-insulating walls.

A smart retrofit adds sensing and control: equipment that responds to occupancy, time of day, and weather, so savings don't depend on someone remembering to flip a switch.

Why it matters

~40%

of U.S. energy use goes to buildings, according to the Department of Energy.

~30%

of the energy used in commercial buildings is wasted on average, per ENERGY STAR.

75%

less energy used by ENERGY STAR LEDs compared with incandescent bulbs.

Most buildings standing today will still be in use for decades, so improving existing buildings, not only constructing efficient new ones, is central to reducing energy costs and emissions. Retrofits also tend to improve comfort, air quality, and equipment reliability.

Common upgrades

LED lighting

Low cost · fast payback

ENERGY STAR certified LED bulbs use at least 75% less energy than incandescent lighting and last up to 25 times longer. Replacing fluorescent tubes and HID fixtures in older commercial spaces is one of the most common first steps.

Smart controls & sensors

Low to moderate cost

Occupancy sensors, daylight dimming, and scheduling turn lighting and equipment off when spaces are empty. ENERGY STAR certified smart thermostats save about 8% on heating and cooling bills on average.

Building automation (BAS)

Moderate cost

A building automation system ties HVAC, lighting, and ventilation together so they run on schedules and respond to real conditions, and it makes problems visible before they waste energy.

Heat pumps & efficient HVAC

Higher cost · long life

Heat pumps move heat instead of generating it. The U.S. Department of Energy notes they can cut electricity use for heating by about 50% compared with electric resistance heating. Older rooftop units and boilers are frequent replacement candidates.

Envelope: insulation & air sealing

Varies

Sealing leaks and adding insulation reduce how hard heating and cooling systems have to work. Window upgrades and cool roofs can also help, depending on climate and building type.

Retro-commissioning

Low cost

Tuning existing equipment so it runs as designed (fixing schedules, sensors, and setpoints) often finds savings without buying anything new.

How to prioritize

1
Measure first
Benchmark the building's energy use (ENERGY STAR Portfolio Manager is free) so you know where it stands and can verify savings later.
2
Start with low-cost measures
Lighting, controls, and retro-commissioning are usually fast to install and pay back quickly.
3
Reduce load before replacing equipment
Fixing the envelope and controls first can mean a smaller, cheaper HVAC system when it's time to replace one.
4
Time big upgrades to end of life
Replacing equipment when it's already due avoids paying twice and makes efficient options easier to justify.
5
Get a professional audit
Tools like RetrospectIQ help you shortlist opportunities; an audit confirms costs, savings, and sequencing for your building.

Incentives

Utility rebates, state programs, and federal tax provisions can offset a meaningful share of retrofit costs, but they change often and vary by location. Check DSIRE and your electric and gas utility for current programs before planning a project.

Some cities also require large buildings to benchmark and report energy use. In Atlanta, for example, the Commercial Buildings Energy Efficiency Ordinance covers larger commercial buildings. Confirm current requirements with your city.

Glossary

Retrofit: Upgrading an existing building's systems or structure to improve performance.
Benchmarking: Tracking a building's energy use over time and comparing it with similar buildings.
Energy audit: A professional assessment of where a building uses energy and which upgrades would pay off.
EUI: Energy Use Intensity: annual energy use divided by floor area, used to compare buildings of different sizes.
HVAC: Heating, ventilation, and air conditioning.
BAS: Building automation system: centralized control of HVAC, lighting, and other systems.
Payback period: How long an upgrade's savings take to cover its upfront cost.
Scope 2 emissions: Indirect emissions from the electricity, heat, or steam a building buys.

Sources & further reading

Figures are general averages from the sources above; results for a specific building vary.

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Smart retrofits and energy savings, explained