Decarbonizing Buildings

The energy required to power our buildings make up 42% of our GHG emissions.  To reach our goals, they must be powered carbon-free.

What is Building Decarbonization?

What is Building Decarbonization?

Decarbonization is the process of removing fossil fuels from a building’s energy use and using appliances that only use clean electricity. 

Strategy 1 focuses on growing clean electricity. Strategy 2 focuses on improving energy efficiency (Play 2.1), supporting existing buildings to be 100% electric (Play 2.2), and achieving all-electric new construction (Play 2.3).

Buildings in Sunnyvale typically use fossil fuels (namely natural gas) for heating spaces, heating water, cooking, and drying clothes. As with vehicles, carbon emissions from buildings can be reduced by switching from fossil fuels to clean electricity for residential or commercial building energy needs.

What is Building Decarbonization?

What are the Benefits of Building Decarbonization?

  • Healthier and safer homes
  • Money and energy savings
  • Clean air 
  • Local green jobs through retrofitting
  • Sustainable environment

Play 2.1 Reduce Energy Consumption in Buildings

Efficiency First

There are two broad strategies we use to reduce overall energy use. First, we must address existing buildings. There are many homes and other buildings throughout the community that were built to old efficiency standards and are using outdated heating, cooling, and lighting systems. We can address these through “deep energy retrofits” to make old buildings as efficient as new buildings.

In January 2021, Sunnyvale's new Reach Codes went into effect. All new construction in Sunnyvale is now required to install solar and electric vehicle components. Reach Codes also prohibit the installation of gas appliances.

What is a Deep Energy Retrofit?

A deep energy retrofit (DER) is broadly categorized as an energy conservation measure in an existing building that comprehensively addresses building systems and insulation to optimize all energy use. Deep energy retrofits achieve at least a 50% energy use reduction by:

  • Upgrading mechanical systems, lighting systems, and appliances
  • Insulating walls, roofs, crawlspaces, and foundations
  • Upgrading HVAC and plumbing
  • Replacing windows
  • Air sealing
  • Installing renewable energy systems where possible.

US Department of Energy - Sunnyvale Case Study

Play 2.2: Support Electrification of Existing Buildings

Electricity’s Share of Energy and Emissions

Electricity has been a steady and even slightly declining share of overall building energy use since 2008. However due to the reductions in grid carbon intensity, its share of GHGs from buildings has fallen dramatically from 68% to just 1%!

The pace of renewable energy deployment will soon make electricity use nearly carbon free, but without reductions in the quantity of natural gas used, we will soon hit the floor for how far renewable electricity can take us towards our goals. To continue on a pathway to eliminating carbon from all our energy use, the share of electricity meeting all our energy needs including heating and cooking will need to rise to 100% as our electric supply gets ever cleaner.

Play 2.2: Support Electrification of Existing Buildings

Reduce Energy Use in Existing Buildings

Just as in energy efficiency, meeting our targets will require addressing both existing and new buildings with electrification. To accomplish this all gas appliances in a household would need to switch to electricity. 

Furnaces, water heaters, and even gas cooking appliances will need to be changed out. Luckily there are ample rebates available to help speed the transition. Interested in trying out an induction cooktop? You can now borrow one from Sunnyvale's Public Library, learn more here. Ready to purchase an induction cooktop? SVCE can help you shop and save.

Staying on track to meet our overall carbon reduction goal will require us to hit targets for the electrification of existing buildings.

Heat pumps work by transferring heat rather than creating it, which delivers hot water more efficiently.

Image Source from Geoexchange.org

Play 2.2: Support Electrification of Existing Buildings

Electrification of Existing Buildings

A critical change in our energy system will be the transition from direct combustion of fossil fuels to heat our buildings in favor of electricity that can be sourced renewably.  Heat pumps help support decarbonization targets, by fuel switching from the City’s largest source of emissions in buildings (natural gas) to clean renewable energy. 

The City’s initiative will focus on supporting installing efficient, electric systems to heat water and heat/cool interiors. Heat pump space and water heaters are high-efficiency alternatives to natural gas systems and and have the potential to be powered by carbon-free electricity.

Silicon Valley Clean Energy (SVCE) is offering rebates to our single-family and multi-family household customers to upgrade their water heaters to electric water heaters. Learn more from SVCE. Sunnyvale residents make up 30% of the participation in the SVCE water heater upgrade program. This means that at least 71 Sunnyvale residents have taken steps toward electrifying their home. You could be next!

Play 2.2: Support Electrification of Existing Buildings

New City Facilities

The City has committed to electrifying municipal buildings upon rebuild or significant remodel. The new City Hall building, part of the Civic Center Modernization Project, will be a LEED Platinum, zero-net energy and all-electric building. The City Hall is scheduled to be complete in 2023.

  Rendering of the new city hall showing an open plaza and green space.

Play 2.3: Achieve All-Electric New Construction

Clean From the Start

Electrifying existing buildings is critical, but we will not be able to eliminate fossil fuel use if we are still creating new buildings that rely on it. While the state requires moving toward Net Zero Energy for new construction, the City will work towards incentivizing and promoting all-electric new construction options for deep decarbonization.

To do this we have passed Reach Codes for buildings, which prohibits all new construction from installing gas appliances. We have also created a new tool to help homeowners calculate what it would take to make their home go all-electric. This can help homeowners understand if their electrical panel needs to be upgraded. We are also evaluating how taxes and other fees affect builders' and homeowners' choice of going electric.

Play 2.3: Achieve All-Electric New Construction

What is Net Zero Energy?

The term "net-zero" can be a little confusing, but the important thing is that these buildings are as efficient as they can be and produce as much of their own energy as possible.  There may be times of the day or year when they need to draw power from the grid, but these  are balanced by the times when they are producing more energy than they need.  Taking into consideration that balance, they can be considered "net-zero" energy.  

Net-zero buildings are state-of-the art construction today. As we continue to strive for more improvements in buildings, and better onsite renewable energy systems, we could soon see more buildings that consistently produce more energy than they consume.

Achieving net zero energy will require steps to address carbon reduction, as well as increase local cabron funds, renewable energy supply, and energy efficiency in existing buildings.

Be Part of the Solution!

Electrify Your Home

Many rebates are available to help you save energy and transition away from natural gas in your heating systems.


Silicon Valley Clean Energy (SVCE) is offering rebates to our single-family and multi-family household customers to upgrade their water heaters to a clean and electric
Take advantage of rebates and financial assistance programs that can help you reduce your carbon footprint at home. You’ll save energy, water — and money, too.