Decarbonizing Buildings

The energy required to power our buildings make up 38% 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 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are many homes and other buildings throughout the community that were built to old efficiency standards and are using outdated heating, cooling, and lighting systems.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.

    We can also do more to slow the growth in energy use from new buildings by staying on the leading edge of building codes and making sure that each new building as efficient as it can be. Sunnyvale is set to update to the latest Reach Code in Fall of 2020.

    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 12%.

    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. 

    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

    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.

    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 are evaluating code and permitting processes to streamline building electrification and working to ensure that taxes and other fees make all electric buildings the smart choice for builders from the beginning. We are also looking to modify Sunnyvale's long standing Green Building Program to further incentivize all-electric buildings.

    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.

    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 times are balanced by times when they are producing more energy than they need.  On balance, they can be considered "net-zero" energy. 

    Net zero buildings are state-of-the art construction today and 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.

    Be a 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

    Heat Pump Rebates
    Take advantage of rebate and financial assistance programs that can help you reduce your carbon footprint at home. You’ll save energy, water — and money, too.