Building Electrification 101

What is Building Electrification?

Building electrification is the process of replacing fossil fuel-powered building systems and appliances, such as gas or fuel oil, with electricity. Electrification allows buildings to operate more efficiently and with lower emissions, regardless of how the electricity is generated. And with Illinois committed to generating 100% of its electricity from clean energy sources by 2045, electrifying building systems now puts your building on a clear path toward being fully powered by renewable energy. 


Why Electrify?

Electrification is a core component of in the process of reducing or eliminating carbon dioxide (COâ‚‚) and other greenhouse gas emissions in buildings. Shifting to clean energy systems is one of the most direct ways buildings can support healthier communities. In Illinois, buildings are the largest source of greenhouse gas emissions, accounting for over 70% of the state's total. Decarbonizing buildings requires moving away from oil, gas, and coal and toward electricity generated from renewable sources. Improving building performance through retrofits and energy efficiency upgrades further reduces emissions. 


Electrification can also improve efficiency, reduce operating costs, improve indoor air quality, and enhance safety. It also protects your building against the risk of future climate regulations requiring early replacement of combustion equipment. Multiple proven electrification options are available now, and more building owners across Illinois are switching to electric systems.

What Does Electrification Mean in Chicago and Illinois?

Illinois already sources the bulk of its energy from carbon-free sources. The state generates more electricity from nuclear power than any other state — nuclear accounted for 58% of electricity generation in 2020. Coal has been the second-largest source for electricity generation but has been declining since 2009. The Climate and Equitable Jobs Act, signed into law in 2021, sets a clear timeline for full grid decarbonization in Illinois by 2045. 


At the same time, the state's energy infrastructure is aging and increasingly strained as demand grows. To meet climate commitments while keeping the grid reliable and costs manageable, Illinois must reduce energy consumption and carbon emissions. 


As the grid shifts toward a higher share of renewable energy, energy efficiency requirements for new and existing buildings will also become more stringent. To address both at once, electrification options should be evaluated alongside energy conservation measures (ECMs) to reduce overall electricity demand before fully electrifying a building. Starting January 2025, Illinois made Stretch Energy Codes available for municipal adoption, giving cities and towns across the state a practical tool to reduce building energy consumption through increasingly stringent commercial and residential building codes. 


How and When to Electrify

New construction should target all-electric systems from the start. For existing buildings in the Illinois market, the practical approach is to take measured steps to build a realistic path toward full electrification. 


Systems to consider when planning electrification include: 


  • Mechanical heating systems (boiler or direct-fired gas heating) 
  • Domestic hot water systems (water heater) 
  • Appliances (gas range, gas clothes dryer) 
  • Backup energy sources (generators) 

Key factors that will affect an existing building's electrification path: 


Gas-using systems 10 years or older should be evaluated for electrification. Systems less than 10 years old generally don't need to be replaced until they reach the end of their useful life — roughly 10 years for smaller appliances and up to 40 years for larger systems like steam or hot water boilers. Newer buildings should focus first on improving the efficiency of current systems, then map out replacement strategies that support future electrification. 

If a building system has experienced a significant drop in efficiency, switching to an all-electric option may make sense before the end of its useful life. For larger buildings, an energy audit combined with energy modeling is the best way to identify where early replacement would deliver a positive return. 


Variable Frequency Drives (VFDs):

Adding VFDs to motors—pumps, fans, and similar equipment—lets them run at the speed the job actually requires, rather than full power all the time.  

Existing buildings will need an assessment of their electrical infrastructure to determine available capacity for converting some or all systems from fossil fuels to electric. 




Windows: 

Single-pane windows are a significant source of energy loss. Replace them when possible, or apply Low-E film to improve the performance of what you already have.  Review the Hub Tech Primer on High Performance Windows.  



Building owners should evaluate central plant and shaft space to confirm that physical modifications to systems are feasible. 

If a building owner can accept a payback period of 10 years or longer, electrification is generally recommended. This is especially relevant for larger institutional owners or operators who can use salvaged components from existing systems to extend the life of functional equipment in the interim. 

Building Components to Electrify and Available Options

Table 1: Common fossil fuel-powered building components that can be electrified 

(listed in typical application greatest to least fuel usage)


  1. Natural gas heating
  2. Natural gas water heating
  3. Natural gas cooking appliances
  4. Natural gas clothes dryer
  5. Emergency generator (diesel)

  1. Natural gas heating
  2. Natural gas water heating
  3. Emergency generator (diesel)

Building electrification also creates an opportunity to upgrade a building's control systems to: 


  1. Better monitor a building's energy consumption 
  2. Identify opportunities to shift loads to times when the grid is less carbon-intensive 
  3. Enable participation in demand-response programs that can generate revenue to help offset electrification costs 
  4. Prepare buildings for grid integration, lowering overall utility costs and increasing building value 
  5. Increase the value of energy efficiency efforts 
  6. Reduce emissions 

 

The strategies below outline the systems where fossil fuel sources are most commonly used and their electric alternatives. 

Gas-fired component. 

Boilers used for space heat — and sometimes combined with water heating — are most common in multifamily residential and educational buildings, but can also be found in some commercial buildings. 


Electrification replacement options.

Mechanical heating options to replace gas-fired boilers include: 

  • Heat recovery chillers (air-to-water heat pump): provide simultaneous cooling and hot water production for space conditioning. 
  • Geothermal heat pumps (water-to-water heat pump): provide simultaneous cooling and heating for space conditioning; work best for larger campuses and new buildings with space for boreholes. 
  • Air-source heat pumps (air-to-air heat pumps): can meet both heating and cooling needs for a building. 
  • Thermal batteries: use low-demand grid periods or renewable energy to store excess heat or ice for use at other times; can be implemented alone or in combination with one of the above options depending on system size. 
  • Heat recovery from rooms with heat loads (e.g., telecom rooms, electrical exhaust): redesigned mixed-use spaces that capture and reuse heat generated by cooling those rooms in another application. 

Gas-fired component.  

Gas water heaters are most commonly found in multifamily residential buildings as either individual units or central systems. Educational and commercial office buildings also use a significant number of central systems — with booster and instantaneous heaters where needed — to meet hot water demand. Pool heating, while not a major factor in Illinois, also accounts for a portion of fossil fuel-dependent water heating demand. 


Electrification replacement options.  

Electric water heaters can replace gas units, and often improve efficiency while saving space. In some applications where rooftop space is available, solar water-heating systems can also offset water-heating loads. Options include: 

  • Individual-unit electric water heaters: Multifamily buildings can install tankless water heaters sized appropriately for each unit's demand. 
  • Floor-by-floor electric water heaters: Tankless water heaters can be grouped together in a back-of-house location, or commercial systems sized to serve an entire floor's demand. 
  • Central systems: Whole-building electric solutions such as hot-water heat pumps, with a focus on efficient piping distribution to minimize heat loss. 
  • Pool heaters: Heat pumps sized to the gallons of pool or hot tub water can replace gas equipment for year-round use. 
  • Thermal batteries: Either alone or in combination with one of the above options, depending on system size. 
  • Heat recovery from rooms with heat loads (e.g., telecom rooms, electrical exhaust): redesigned mixed-use spaces that capture and reuse heat generated by cooling those rooms in another application. 
  • Solar thermal water heating: Indirect solar thermal systems can provide seasonal water heating paired with other electric options, though analysis should compare using rooftop space for solar PV paired with an electric option — this often proves more cost-effective. 

Gas-fired component. 

Gas-fired kitchen appliances typically include ovens, stoves, ranges, cooktops, and fryers. 


Electrification replacement options. 

Electric resistance cooking equipment delivers heat three times more effectively than gas equivalents, and induction systems are even more efficient. In commercial kitchens, electric options are gaining wider acceptance — electric ovens are increasingly common for baking, while gas is still used in some stovetop applications. Commercial electric induction cooktops, induction woks, and fryers are available on the market today. Owners and operators should weigh the cost of replacement against the cost of maintaining existing gas infrastructure to determine the right timing for electrification. 


In residential buildings where residents may prefer gas stoves, owners should review existing ventilation and exhaust systems alongside electrical infrastructure and cooking performance before making a switch. Switching to all-electric oven, stove, and range appliances delivers air quality and health benefits — gas stoves are a primary source of combustion pollution inside the home. Unlike commercial applications, residential electric appliances are widely available and don't require cost analysis to justify. ENERGY STAR-rated equipment is available for both residential cooking appliances and commercial food service equipment for additional efficiency savings. 

Gas-fired component. 

In multifamily residential buildings, gas clothes dryers are commonly found in individual units and central laundry rooms, and are often the largest appliance energy load in the building. 


Electrification replacement options. 

Switching to electric clothes dryers improves efficiency from approximately 30% for gas dryers to over 200% for electric models. ENERGY STAR-rated electric dryers improve efficiency further with sensor drying and low-heat settings. Eliminating gas dryers in urban buildings also enables the use of ventless units, reducing or eliminating the need for dryer exhaust systems and saving both energy and installation cost. 

Fuel oil-fired component. 

Diesel-powered emergency generators provide backup power during outages. 


Electrification replacement options.

Alternatives to fossil fuel generators include: 

  • Battery-stored backup power: Supports the operation of lights, appliances, and communications systems during a power outage. 
  • Solar-powered generators: Portable, rechargeable, all-electric battery-powered units. 

What Systems Need Further Research and Innovation?

Demand is growing for higher-efficiency, lower-emission systems in large buildings, but some newer technologies are still working toward widespread, proven adoption. Higher upfront costs can be a barrier when rebates or incentives aren't yet available — though as with solar PV, broader adoption tends to bring costs down over time.


The following technologies are expected to see expanded development and market availability in the near term: 


  • Heat pumps that deliver high-temperature water for heating applications where replacing terminal units would be cost-prohibitive 
  • Thermal storage technologies paired with heat pumps to deliver high-temperature water and steam without requiring as much electrical infrastructure 
  • Commercial kitchen induction cooking equipment 
  • Hydrogen fuel solutions — preliminary research and pilot projects are underway 

What's next?

Whether this guide is your starting point or a helpful check-in on work already underway, the path forward is the same: take action and stay connected. If you have a Building Electrification Plan in place, check in regularly with the Building Energy Hub to stay current on developments related to your priority systems and equipment. If you still need to develop a plan, bring together your operations, maintenance, and management team along with trusted contractors and advisors and get started.


No matter where you are in the process, the most important step is developing your plan and following through. These steps and planning will enable a better-performing building that works well for occupants, owners, and the broader community. 

This resource is based upon content originally developed by the Institute for Market Transformation for the Building Innovation Hub, with funding  and support provided by the District of Columbia’s Department of Energy & Environment.


This material is based upon work supported by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) under the Building Technologies Office Award Number DE-EE0010930. (DOE-ELEVATE-0010930-13)