TECHNICAL RESOURCES

This page has been developed to provide guidance and help direct competition teams to high quality educational resources to support the development of competition submissions.  General Resources & Training consists of introductions to the fundamental concepts of the competition, as well as opportunities provided by the California utility companies and AIA California.  Three books are also recommended as further resources.  

The remainder of the Technical Resources page provides resources that are organized in the steps that  teams might approach the competition and their design.

1. California Context: Goals, Codes & Cities

2. Setting Goals / Targets

3. Passive Systems and Building Envelope

4. Active Systems

5. Integrating Renewable Energy

6. Modeling and Simulation

7. Load Shapes - why are they important?

General Resources & Training

The trainings below are overviews or introductions to a few topics specific to this competition:

• Energy-Efficient All-Electric Buildings: Case Studies

• Re-designing Good Design: High-performance Architecture for a Low-carbon World

• Using Building Energy Simulation

• Basics of Solar Electric Systems

  
  

The California utilities and AIA California offer a number of free simulcast, online on-demand, and in person trainings:

• SCE - Energy Education Centers

• PG&E - Energy Training Centers

• SDG&E - Energy Innovation Center

• SoCalGas - Energy Resource Center

• Sacramento Municipal Utility District - Online Resources

• AIA California - Climate Action Webinar Series

California Context: Goals, Codes, & Cities 

Building decarbonization is a key strategy to  achieving California’s aggressive climate goals.  California must reduce GHG emissions 40% from 1990 levels by 2030.

California’s Fourth Climate Change Assessment  highlights the potential impacts from climate change  on California. In 2020, California experienced  record-shattering wildfires with widespread smoke  and intense, dangerous heat events. 

Projects designed and constructed in California  must meet certain energy use requirements in the  building code. California’s Building Energy Efficiency  Standards (Title 24) focus on reducing energy  used in new construction and existing buildings. 

Building energy codes are still fundamentally based on energy use predicted by energy models. The  requirements for the latest version of Title 24 for  low-rise multifamily projects, and numerous other  resources, can be found at Energy Code Ace. 

An increasing number of local jurisdictions in California are enacting building energy codes that are more stringent than the state codes, encouraging decarbonization primarily through encouraging or requiring all-electric new construction. 

Setting Goals & Targets

Successful project teams set energy and emissions targets at the beginning of the design process. The energy target is generally the site Energy Use Intensity (EUI), or the annual energy consumption divided by conditioned floor area, and is expressed in units of kBtu/sf/yr.

To meet the EUI target, teams focus first on energy efficiency through optimizing for climate and site, resolving major design moves that improve energy performance, and then integrating and optimizing the envelope, passive strategies, and high-performance, carefully sized building active systems and equipment. Finally, the team integrates renewable energy and any energy storage. Once the project is completed, teams are increasingly tracking project performance to ensure systems perform as designed, and to adjust system performance or controls if needed. 

A building’s complete lifecycle, from pre-design through long term operations - and beyond, affords numerous opportunities for energy modeling to enhance performance. Energy efficiency, optimized through energy modeling at all building design and construction stages, and periodically during post-occupancy, can achieve the triple bottom line goals of sustainability.

Additional analysis is needed to determine the carbon emissions of the building during design, and later, operation. The operational carbon emissions of buildings are generally determined by multiplying the energy use by an emissions factor. The emissions factor varies by fuel, time of year, and time of day. If an hourly emissions factor by fuel type is available for the location or utility, it can be applied to the hourly energy use by fuel type and used to assess how to reduce carbon emissions for specific times of day, seasons, or on an annual basis. Carbon emissions are generally expressed in pounds or tons of carbon emitted, depending on the emissions factors and time frame. 

The embodied carbon is the emissions connected to the equipment, materials, and construction practices. Certain materials or building components have more carbon than others, so some designers also have goals to reduce the embodied carbon through careful choices, or by reusing existing buildings where feasible.

The following excerpt comes from the AIA document, Design for Energy. It provides information on best practices for designs that can reduce energy use and eliminate the use and dependence on fossil fuels. The tips provided focus on energy benchmarking and goal setting, passive design features/climate responsive design, energy modeling, onsite renewables (solar, wind), Net Zero Energy/Net Zero Carbon Building, and commissioning. 

Energy benchmarking and goal-setting 

• Windows are a major indicator of total building energy use. A Window-to-Wall Ratio (WWR) above 40 percent will provide no additional benefit for daylighting but will cause significantly higher conditioning loads. Keeping the WWR between 30 percent and 40 percent will set the stage for both good daylighting and energy performance. (Limiting the WWR may feel like a design restriction for project teams; however, the way designers leverage constraints to their advantage is one of the key considerations of the AIA COTE® Top Ten Awards, celebrating both beauty and performance.)

• Very efficient buildings tend to have a great percentage of the energy coming from plug loads. Like LPD, it is important to set a goal for plug loads and check them throughout the design process. Determine the typical plug load (in W/sf) for buildings with a similar program, and aim for a 25 percent to 50 percent reduction. Scheduling nonessential plug loads to turn off when not in use can be a primary strategy for reaching 50 percent reduction.

Passive Systems & Building Envelope

Careful design of the building envelope and building openings to optimize appropriate passive strategies for the climate can reduce heating, cooling, and lighting energy use.

The following excerpt comes from the AIA document, Design for Energy. It provides information on best practices for designs that can reduce energy use and eliminate the use and dependence on fossil fuels. The tips provided focus on energy benchmarking and goal setting, passive design features/climate responsive design, energy modeling, onsite renewables (solar, wind), Net Zero Energy/Net Zero Carbon Building, and commissioning. 

Passive design features/climate responsive design

•  Indigenous and native typologies offer great clues for climate-responsive design. Prior to the advent of air conditioning and other modern technologies, materiality, massing, orientation, roof design, and penetrations were the strategies used to build comfortable and protective enclosures. Use vernacular and indigenous buildings as a guide to determine the passive strategies that are most applicable for a given region.

• Focus on window to wall ratio, orientation of glazing, and sun shading as major passive strategies. WWR should be limited in all climates, but the location of glazing will shift depending on the latitude. In colder climates, primary glazing should be on the south, to collect beneficial solar radiation. In warmer climates, primary glazing should be on the north, to avoid harsh summer sun. For the most part, windows should be shaded on the south, east, and west in all climates 

• Envelope air tightness is just as important as insulation but often receives less attention. To ensure good air tightness, designate one layer of the assembly as the air barrier and ensure that this layer is continuous on six sides, with all seams taped, and all penetrations filled. Use a blower door test to verify the building’s air tightness, both for mockups and for the whole building.

• Provide operable windows for all occupants so that the building can benefit from fresh outdoor air when the weather is agreeable. Arguments have been made that non operable windows provide better control for building systems and save energy. This can be true only if the building knows more about each occupant’s thermal comfort than the occupant does. This is not the case; always provide operable windows.

Active Systems

There are a number of common “active” building systems that are used in low-carbon, ZNE, and high performance buildings. Optimizing the performance of the HVAC, water heating, lighting, and plug loads separately and in the building as a whole is critical to achieving the energy and carbon targets set early in the design process. 

Integrating Renewables

Zero carbon buildings, like ZNE buildings, are grid tied, or connected to the utility grid. The “net” part of ZNE results from consuming electricity from the grid and feeding electricity into the grid that is generated at the site. Increasingly, buildings with solar PV are also including on-site batteries for energy storage in their designs.

Modeling & Measuring Energy (& Carbon) Performance

Achieving low-carbon building performance requires careful modeling of the predicted performance of the building systems for decision-making during the design process. As you are modeling and reviewing model results, keep the following questions in mind:

• What does this model tell me?

• Which option is better? 

• Does this result make sense? 

Once the building is constructed and occupied, it is important to track the energy performance, and to review whether the building is performing as modeled. While reality is always different, due to real weather, occupant behavior, overall occupant density, or other factors, this comparison may reveal systems or controls that need commissioning to improve performance immediately, and also opportunities to improve energy performance over time.

Load Shapes - Why they are important

The building’s load shape is the amount of energy it needs over time, the sum of all the end uses. The load shape varies over the day and year, depending on occupancy patterns, seasonal weather, and other factors. Designers and energy modelers often use the “8760” energy model results, or the hourly energy use for the whole year, for energy and emissions target analysis. To calculate the emissions from a building design, hourly energy simulation results are multiplied by an hourly emission factor. It’s important to note that these emission factors vary by season and by the time of day. Emission factors in California are the lowest in the middle of the day, when ample renewable energy generation allows for a cleaner electrical grid mix. As a result, even if energy use is high during the middle of the day, the resulting emissions may be relatively low. Shifting energy use from hours with higher emission factors to those with low emission factors can help your design meet zero carbon targets. Careful selection of building systems and technologies can result in the ability to better optimize the load shape to reduce carbon emissions. Energy storage systems also allow additional flexibility in shaping the load profile.