What you can do right now

What You Can Do Right Now: 10 Ways to Reduce Concrete’s Carbon Footprint

June 8, 2022| Climate Action, What you can do right now| AIA California

Climate Action: 10 Ways to Reduce Concrete’s Carbon Footprint

Lionel Lemay | Executive VP, Structures and Sustainability, National Ready Mixed Concrete Association

The following is a list of strategies for reducing concrete’s carbon footprint through collaboration, design optimization and performance-based specification:

Communicate carbon reduction goals
Ensure good quality control and assurance
Optimize concrete design
Specify innovative cements
Specify supplementary cementitious materials
Specify admixtures
Set targets for carbon footprint
Don’t limit ingredients
Sequester carbon dioxide in concrete
Encourage innovation

Why is this important?

According to the UN Environment’s Global Status Report 2017, the world is projected to add 2.5 trillion sq ft (230 billion sq meters) of buildings by 2060 driven by soaring needs for housing and infrastructure development. The UN report urges building designers and owners to reduce operational carbon by designing disaster-resilient buildings for the future with zero-energy consumption. Concrete has long been the material of choice for energy efficient and disaster resilient buildings and infrastructure. The UN report also urges the building industry to reduce the embodied carbon of building materials. Given the amount of concrete used in buildings, and the carbon footprint of making cement, the challenge is to offer lifetime benefits of concrete at a lower carbon footprint.

To meet this challenge, the National Ready Mixed Concrete Association (NRMCA) adopted in 2012 the Architecture 2030 Challenge, which has goals to reduce operational carbon and embodied carbon from the built environment to net zero by 2050. However, concrete is unique among building materials. Design professionals and contractors have a greater influence on concrete formulation than they do with other building products. Therefore, it is critical that architects, engineers, contractors and concrete producers collaborate to reduce concrete’s carbon footprint. And, given that structural engineers often specify concrete on projects, architects need to know more about how to talk with their consultants to reduce the embodied carbon in concrete.

Things you can do right now

Communicate carbon reduction goals
Sustainability goals, including carbon footprint targets, should be communicated to the design team and to product manufacturers. (This not only applies to concrete but to the majority of building products specified.) We suggest collaborating with your structural engineer, local concrete producers and contractors. Invite them in for a meeting or charrette with your design team. Understand what technologies and concrete ingredients are available locally. Emphasize the carbon reduction goals for the project in pre-bid meetings. Carbon reduction of 50% and higher is readily achievable.

Recommendation: State a carbon reduction goal (carbon budget) for all the concrete on the project. See Section 1.2 of NRMCA Guide Specification.

Ensure good quality control and assurance
Concrete is made from local materials and its performance can be affected by weather conditions, variability of materials, delivery, placing, handling, and testing. Although the materials used to make concrete meet rigorous standards, the variability can be quite high. Concrete rarely tests well when proper manufacturing, installation and testing protocols are not followed. If test results constantly show lower strength, then the only way to overcome that is to increase overdesign which generally raises cementitious material content. For example, if poor testing increases the necessary overdesign from 600 to 1000 psi the cementitious materials content would increase by roughly 40 lbs for 4,000 psi concrete, increasing the embodied carbon footprint by as much as 6%.

Recommendation: Specify minimum qualifications for the concrete producer, installer and testing facility. See Section 1.7 of NRMCA Guide Specification.

Optimize concrete design
If a structural element such as a column or beam is designed larger than required, then excessive concrete is being used which increases embodied carbon. Alternatively, for a high-rise building, reducing the size of the columns might be critical to keeping the rentable space to a maximum. That means using high strength concrete which generally means higher carbon footprint, but at lower volume with a net benefit to the project. Additionally, higher quality materials can allow for innovative design strategies such as increased deck spans with less deflection, or narrower columns to withstand equivalent seismic and wind drift.

Recommendation: Discuss sizing of structural members with your engineering consultants. Use life cycle analysis software to quickly calculate the embodied carbon of concrete elements throughout design iterations (structural and architectural). Also, consider exposing concrete wherever possible. Finish materials have a considerable carbon footprint and exposed concrete can be attractive and is fire resistant without the need for additional protection. Additionally, exposed concrete has a higher rate of carbon uptake through a process called carbonation, which permanently sequesters CO₂ directly from the atmosphere (see Strategy 9).

Specify innovative cements
There are several innovative cements on the market. The most common are called blended cements. These combine ordinary portland cement (OPC) with other materials. The most common type of blended cement is portland-limestone cement (PLC) or, technically, ASTM C595 Type IL (pronounce “one el”) cement. This blended cement combines up to 15% limestone interground with OPC to make a cement with a carbon footprint that is up to 10% lower than OPC with performance that is identical to— and in some cases better than—OPC. As a 1-to-1 replacement, incorporating PLC into a project allows for direct reduction in carbon across all classes of concrete. There is also another standard, ASTM C1157, for performance based blended cements with no limits on cement composition which allows considerably more flexibility.

Recommendation: Coordinate with your structural engineer to permit the use of all hydraulic cements including ASTM C150, ASTM C595, or ASTM C1157. See Section 2.2 of NRMCA Guide Specification.

Specify supplementary cementitious materials
Nearly all concrete uses supplementary cementitious materials (SCMs). SCMs offer the greatest opportunity for the reduction of carbon footprint today. The most common are fly ash, slag cement, and silica fume in that order. However, there are others, such as metakaolin, volcanic ash, rice husk ash, and ground glass, just to name a few. All of these also enhance the performance of concrete when combined with portland cement, including increased strength, increased durability and enhanced workability. Given that they are often recycled or naturally occurring products, SCMs are a carbon reduction strategy that frequently yields negligible impact to cost.To give an idea of how effective the use of SCMs are in reducing carbon footprint, going from a 100% portland cement mix to a 50% fly ash/slag cement mix can reduce carbon footprint by roughly 40%. Additionally, present day projects can easily realize over 70% cement replacement with SCMs for foundations that won’t experience ultimate loading until the project nears completion.With SCMs other than silica fume, the rate of strength gain might be lower initially, but strength gain continues for a longer period compared to mixtures with only portland cement or blended cement, frequently resulting in higher ultimate strengths. This slower strength gain can sometimes be overcome with admixtures. However, the most common way to overcome slower strength gain is to specify a later test age. For example, foundations are often specified to reach compressive strength tested at 56 or 90 days to allow for slower strength gain.

Recommendation: Permit all types of SCMs in your specification. See Section 2.2 of NRMCA Guide Specification. Coordinate with the engineer and contractor to maximize the use of SCMs while balancing schedule demands including using compressive test age of 56 or 90 days depending on the application.

Specify admixtures
Nearly all concrete produced today uses admixtures. Most enhance the plastic properties in order to make concrete more workable, economical, shorten or lengthen set time, and so on. There are water reducing admixtures that in effect reduce cement demand, accelerators that improve strength gain, and viscosity modifiers that permit concrete to flow into very tight spaces. As an example of how effective admixtures can be, using a water reducing admixture that reduces water content in a mixture by 12% will result in a reduction of cement content by 70 lbs for equivalent slump and strength with a carbon reduction of roughly 10% for 4,000 psi concrete. High-range water reducing admixtures can reduce water content by as much as 40%.

Recommendation: Permit all types of admixtures in your specification. See Section 2.2 of NRMCA’s Guide Specification.

Set targets for carbon footprint
The best approach to achieve carbon footprint reductions is to use whole building life cycle assessment to set a carbon budget for all the concrete on a building. Use industry average benchmarks to establish a baseline and use industry wide environmental product declarations to establish a carbon budget (see recommendations). It is still necessary to have a general idea of what the carbon footprint of each mix will be to set a carbon budget for the building, but by setting a carbon budget for all the concrete, it provides enough flexibility to the contractor and concrete producer to meet the all the performance criteria such as strength and durability while also meeting carbon reduction goals.For some elements, such as post-tensioned slabs, the ability to reduce carbon footprint from industry average benchmarks will be difficult because of early strength requirements. But for other elements such as foundations and shear walls, the carbon footprint can be significantly lower than benchmark. The carbon budget approach allows for the contractor and concrete producer to combine many of the strategies presented such as implementing good quality control and using innovative cements, SCMs and admixtures to help meet the performance requirements and carbon reduction goals.

Recommendation: Specify a target global warming potential (GWP) for all the concrete on the project by using NRMCA Industry Wide Environmental Product Declarations and Benchmarks to estimate how to compare your proposed designs to a baseline (benchmarks). See Section 2.11 of NRMCA’s Guide Specification.

Don’t limit ingredients
Do not list a maximum or minimum cement content, maximum or minimum SCM content, or quantity of admixtures. These random limits on material ingredients in project specifications limit the concrete producer’s ability to meet performance criteria, including carbon footprint reductions. As an example, unnecessarily limiting the water-cementitious ratio to 0.45 versus an alternative of 0.50 can result in an increase in GWP of 7-12%. Instead, use ACI 318’s exposure classification table when conditions would require limits on the water-cementitious ratio.

Recommendations: Include a table in the specification that lists performance criteria such as strength and exposure class without limitations on material quantities. See Section 2.11 of NRMCA Guide Specification.

Sequester carbon dioxide in concrete
Carbon dioxide (CO₂) can be captured or permanently sequestered in concrete through natural processes or carbon mineralization technologies. The rate of carbon uptake depends on exposure to air, surface orientation, surface-to-volume ratio, binder constituents, surface treatment, porosity, strength, humidity, temperature, and ambient CO₂ concentration. Research conducted by Possan, et al., indicates that during its lifetime, concrete can uptake anywhere from 40 to 90% of CO₂ emitted in its manufacturing process. Other commercially viable technologies accelerate carbonation. This is accomplished either by injecting CO₂ into concrete, curing concrete in CO₂, or creating artificial limestone aggregates using CO₂.

Recommendation: Expose concrete as much as possible on projects. Permit the use of recycled and artificial aggregates in concrete. Permit the use of carbon mineralization technologies. See Section 2.2 of NRMCA Guide Specification.

Encourage innovation
For an innovative product or process to be successful, demand must be created, but the current design-bid-build process discourages innovation.

Recommendations: Communicating the carbon reduction goals to contractors and producers during the design process is critical. Let them know that you are looking for innovative solutions. Most sophisticated producers are experimenting on new formulations all the time. Ask them to discuss some of their low-carbon concretes. Will they meet all the performance criteria set by the design team and the contracting team?

Tools and Resources

Guide to Improving Specifications for Ready Mixed Concrete with Notes on Reducing Embodied Carbon Footprint, NRMCA Publication 2PE004‐21c, 2021. www.nrmca.org/sustainability

NRMCA Member Industry-Average EPD for Ready Mixed Concrete NRMCA 2021. https://www.nrmca.org/wp-content/uploads/2022/03/NRMCA_EPDV3-2_20220301.pdf

A Cradle-to-Gate Life Cycle Assessment of Ready-Mixed Concrete Manufactured by NRMCA Members – Version 3.2. NRMCA 2021. https://www.nrmca.org/wp-content/uploads/2022/02/NRMCA_LCAReportV3-2_20220224.pdf.

Possan, E. F. Felix, W. A. Thomaz, CO₂ uptake by carbonation of concrete during life cycle of building structures, Springer International Publishing, Switzerland, October 2016.

Engage the Concrete Design Center for help with sustainable concrete design and specifications, www.buildwithstrength.com/design-center.

Learn about the latest concrete innovations, www.concreteinnovations.com.

What You Can Do Right Now: Design for Daylight and Views

March 1, 2022| Climate Action, What you can do right now| AIA California

Ample daylighting and window views can help make your next building net-zero, healthier, and more sustainable.

By Lisa Heschong, Fellow Illuminating Engineering Society

“Daylighting” is the process of designing and operating interior spaces to utilize natural daylight as their primary source of illumination. Optimizing the distribution of daylight illumination requires climatically appropriate architectural design, cognizant of locale, climate and orientation. Daylight optimized interior design and furniture layouts enable occupants to take maximum advantage of the available daylight; electric lighting design responds to the dynamics of daylight, providing supplementary illumination only where and when necessary. Occupants in successfully daylit buildings regain control of their environment, with the ability to make local adjustments to furniture, window shading systems, and electric lighting to best meet their changing needs over the course of the day and year.

There are many fenestration design strategies, including windows, skylights, atria, and sunlight redirection devices, that can contribute to successful daylighting. Multiple approaches often make for a more robust system. Ultimately, daylighting both benefits from and encourages a holistic design approach; one which integrates input across design professions and establishes performance goals that are pursued continuously throughout building design and operation. Thus, daylighting is a fundamental benefit of good architectural design and coordination.

How are window views different from daylighting?

Windows designed for views provide occupants with a visual connection to the outdoor environment. While view windows may also deliver daylight illumination into a space, they do not necessarily need to be optimized for that purpose. Via thoughtful design, architects become curators of good views, which can add enormous financial value to buildings.

Occupants may get more circadian health benefits[i] from window views than from interior ambient illumination. This is because window views are generally brighter and more interesting, thereby attracting occupants’ attention, both consciously and unconsciously. Window views have also been associated with many other health benefits, including eye health, cognitive performance, and emotional well-being.

How are daylighting and window views related to climate change?

Efficiency: Using daylight as the primary illumination sources inside of buildings during the daytime is inherently energy efficient. No electricity is needed for most of the daylight hours. Fully daylit buildings can be extremely efficient, by using passive solar design principles. During cold weather, sunlight can be utilized for both light and heat (as long as it is ‘gentled’ first, to avoid overheating or glare.) During warm weather, daylight from the sky and broadly diffused sunlight can be more efficient than equivalent electric light sources, contributing less net heat per unit of light and so further reducing building cooling loads. Views can also add to building energy efficiency, by providing the bright vistas that occupants crave, without a need to increase electric lighting power densities.

Sustainability: Daylighting may be the ultimate sustainable design practice. Well daylit buildings have endured for hundreds of years. Buildings with ample daylight and views are easily repurposed, from offices and factories to schools and homes. Windows and glazing materials are long lasting. They can easily last for 50 (or more) years, compared to a 15-to-20 -year life for many electric lighting systems and the current 5-10 year change-over cycle for new electric lighting technologies . While glass industries do utilize a lot of energy, the materials are simple, widely available, and non-toxic. Likewise, maintenance is a piece of cake: water with a little soap or vinegar

Resilience : Daylight is the most reliable and resilient form of interior illumination. It works regardless of power availability and grid reliability. You want to be in a daylight building when your power supply is uncertain, such as after an earthquake, a flood, or a fire storm.

Simplicity : Daylight from windows is easily managed using common materials and common sense, such as curtains, blinds, awnings. Repairs and re-configuration do not require an electrical engineer or computer programmer (as with advanced electric lighting controls.) Thus, in case of failure or reconfiguration, any problems can be easily and quickly solved.

Emergency response: Window views provide essential information about our environmental context, enabling occupants to assess sudden weather changes and other threats. They can also enable essential emergency communication and egress options.

Health: This is the big one. What’s the point of climate adaptation if it leaves people sick or uncomfortable? We now know that we need the circadian cues from daylight (and dark nights) to stay healthy. We have specialized photoreceptors which seek signals from the dynamic colors of daylight to keep our fundamental body and cellular rhythms in sync. Views are likely the most potent form of circadian stimulus inside of buildings, because they are bright; perfectly in sync with the exterior illumination; and most of all, interesting, drawing our attention. As a result, ample daylighting and views are an essential component of IEQ—indoor environmental quality.

Happiness: Daylight and views make people happy. They have been shown to lower depression and anxiety. They have also been shown to motivate healthy behaviors, like more physical activity and better sleep patterns. We could all use a little more happy.

Things you can do right now:

Design buildings that use daylight as the primary form of interior illumination.

Create spaces that have daylight entering from more than one orientation, such as view windows on two or three sides, entering from high windows like clerestories, and/or entering from above, such as from skylights, roof monitors or atria.
Design the electric lighting to supplement the daylight only when and where needed, and to provide appropriate nighttime illumination.

Use clear, highly efficient glazing materials that provide maximum light transmission per window area (VLT of 60% or greater).

Both people and plants benefit from the full spectrum of sunlight, so avoid glazing tints or coatings that change the appearance of the glass.
Instead, minimize heating and cooling impacts via proper shading, orientation, use of triple or quadruple glazing layers, and by keeping total glazing area to the minimum needed for well-balanced daylight and views.
Operable shading systems can also be designed to improve both heating and cooling profiles, thus reducing whole building energy use. When closed during nighttime operations, such operable shading systems also improve privacy and reduce light pollution.

Avoid allowing too much direct sunlight into the space that may cause visual or thermal discomfort for the occupants.

Pay careful attention to solar geometry, and wherever possible, provide exterior shading for windows during the hottest times of the year.
View windows should also include occupant-controlled blinds or shades to provide intermittent privacy and glare control.
Skylights should be diffusing to ‘gentle’ the sunlight and spread daylight broadly
Clerestories and roof monitors should be carefully sized and oriented so that any direct sunlight entering the space will reflect off of another surface at least once before it reaches any eyeballs.

Use design analysis tools that will help you understand the dynamics of daylight in the space. This can include physical models combined with photography and physical measurements, or computerized simulation models that are capable of hourly daylighting analysis.

If you don’t have the expertise to do daylighting analysis in-house, hire a daylighting consultant.
Go visit well-daylit buildings and analyze the strategies used. Learn from the masters.
Read up on daylighting design and analysis in the resources listed below.

Advocate for daylighting design to your clients, to other building owners and occupants, and to public officials.

Access to daylight and window views during the day should be a basic right for all workers. It is a fundamental equity issue for healthy indoor environments.
Help your mechanical and electrical subcontractors better understand how to design in response to the dynamics of daylight, rather than ignoring it or fighting it.
Advocate for minimum daylighting and view requirements in building codes, especially for vulnerable populations such as children, the elderly and low-wage workers.

Resources:

Seven very different books that cover a wide range of the art and science of daylighting:

Visual Delight in Architecture: Daylight, Vision and View by Lisa Heschong, Routledge 2021.

An exploration of the many ways that daylighting and view are important for our health, well-being, social structures and culture, derived from both recent research and personal experience.

The Architecture of Natural Light by Henry Plummer, The Monacelli Press 2009

A lush photographic tour of beautiful daylit spaces designed by great architects

Approved Method: IES Spatial Daylight Autonomy(sDA) and Annual Sunlight Exposure (ASE), published by the Illuminating Engineering Society, 2013

A manual explaining a methodology used to analyze daylight illuminance adequacy in commercial spaces. Soon to be updated. preview_IES+LM-83-12.pdf (ansi.org)

Effective Daylight for High Performance Facades by Kyle Konis and Stephen Selkowitz. Springer 2017

The latest synthesis of work by Lawrence Berkeley National Labs on advanced daylighting strategies and technologies, packed with technical data and examples.

Daylighting: Architecture and Lighting Design by Peter Tregenza and Michael Wilson, Routledge, 2011

A seasoned educator’s guide to architectural daylighting design, including tools, graphics, and case studies.

Windows on the World by Matteo Pericoli, Penguin, 2014

A delightful collection of hand drawings of window views from around the world, accompanied by loving descriptions by the writers who live and work with those views.

Sunlighting as a Form Giver for Architecture by William Lam, Van Nostrand Rienhold, 1986

Old school daylighting advice and case studies by one of the early masters, using physical models for analysis. Out of print, but available used:

More extensive daylighting bibliographies with short reviews:

BOOKS – The Daylight Site | Daylighting research, architecture, practice and education The Daylight Site

77 Best Lighting Design Books | ArchDaily

Online resources:

Daylighting Pattern Guide – New Buildings Institute

A free, interactive tool that helps design teams incorporate proven daylighting strategies into commercial building projects for reductions in lighting power consumption and overall building energy use, from 2015.

“Visual Delight – The Importance of Views in the Workplace” by Lisa Heschong – YouTube

A preview of some topics covered in Visual Delight in Architecture, from a17 minute talk by Lisa Heschong in 2019.

[i]The term ‘circadian’ refers to our body’s daily rhythms, synchronized to the 24-hour day-night cycles of the planet. Biologists have found that every cell in our body follows these rhythms, and just like a complex orchestra, they need a steady signal from a conductor to keep them all in sync. That signal is provided via light receptors in the retina. Disruption of circadian rhythms is associated with impaired sleep, cognitive performance, immune response, and metabolic function; it is also associated with weight gain and obesity, diabetes, hypertension, heart disease, stroke and depression. (For further detail see Chapters 1-3 of Visual Delight in Architecture (Routledge 2021) in references)

Resilient Design: Why It’s Important to Architects

January 19, 2022| What you can do right now| AIA California

By: William Melby, FAIA

What is Resilient Design?

The AIA CA Resilience Design Committee has developed the following definition to guide it efforts:

Resilient Design is planning and designing our built environment to sustain probable impact from progressive climate change and episodic natural disasters.

What are the impacts of progressive climate change and natural disasters?

The cost of weather or climate related disasters is very high. The National Oceanic and Atmospheric Administration (NOAA) map below shows the disaster events, costing over a billion dollars each, that occurred in the United States in 2020 alone.

(1)

In California alone we have had 336 declared disasters between 1953 and 2020. (2)

(2)

In California’s major urban areas, such as Los Angeles and San Francisco, approximately 90% of building stock was built prior to modern building codes, making them more vulnerable to earthquake and other disasters. Unfortunately, only about 20% of building stock in those same areas have earthquake insurance.

A disaster’s impact on local economies and ecosystems can be very dramatic and long lasting. After Hurricanes Katrina & Rita hit New Orleans Louisiana, large numbers of people left the area, and many did not come back. The area is still trying to recover after 15 years.

After the devastating earthquakes, in Christ Church New Zealand, in 2010 & 2011, 70% of buildings needed to be demolished. The waste generated by this demolition created a huge environmental impact. (3)

According to a study conducted by FEMA. 40-60% percent of businesses do not reopen after a disaster and another 25% fail within one year. (4)

The number of electricity outages has doubled in the US over the last decade. (5) This is particularly concerning as electricity is required for both dual fuel buildings and electric-only buildings. Battery backup or other energy storage system should become an important part of a resilient future for projects in California.

What are the benefits of Resilient Design?

The benefits of Resilient Design risk reduction can be economic, such as reduced insurance premiums or maintenance costs, and can also include intangible benefits such as personal safety, business continuity, peace of mind, and the protection of irreplaceable personal belongings.

While designing buildings to meet Building Code requirements will provide a governmentally acceptable level of disaster mitigation, the National Institute of Building Science (NIBS) has shown that additional mitigation, above code requirements, can result in significant safety and financial rewards. The NIBS study shows that building to standards above Building Code can result in savings of up to $11 for every $1 spent on mitigation measures. (6)

Resilient Design and Building Codes?

Building Codes focus on occupant safety and egress. Continued use or cost of repair is not considered. Simple design decisions like building at a higher floor height than Code requirements in flood prone areas can return tremendous results. Building new buildings to be stronger and stiffer than required by the Code can minimize earthquake damage. Use of fire resistive building components can have a tremendous effect on structure survivability.

What are the Costs?

Resilient design cost varies dramatically based upon the types of disasters anticipated and the level of resilience required. Recent reports estimate that an average above code design representing an additional investment of approximately 2% over current building code requirements can reap a substantial payback in a disaster situation. (6)

Some costs can be offset by Government or Utility company programs such as California Earthquake Authority’s Brace + Bolt grant and insurance discount program. (7)

What is the AIA’s Commitment?

The AIA, along with the National Institute of Building Sciences, has gathered a group of design and construction industry organizations representing over 1.7 million professionals to issue a joint statement on resilience. Each organization commits to research, educate, advocate, respond and to plan for a resilient future. The joint statement can be found at: Resilience_Industry_Statement_201026.pdf (aia.org)

Where to start?

Download and become familiar with the specific County or City Hazard Mitigation Plan and County or City Climate Adaptation Plan for your project area. Learn more about the potential disasters that could affect your project location and consider design changes that can mitigate negative effects.

Things you can do right now.

Consider what you can do to avoid risk to your project (site selection, building location or orientation)
Consider how your design can be adapted to reduce risk for your project (material choices, equipment selection)
Consider how your design choices can lower the costs of risk transfer options like insurance. (Incentive programs, discounts)
Consider how building and land use choices impact community resilience goals.
Discuss setting beyond code minimum performance goals with your clients.
Visit the AIA “Hazard mitigation design resources” web page for simple targeted mitigation measures you can take for specific kinds of potential disasters; you’ll also find with many links to more advanced information.
Visit the AIA “Climate Change adaptation design resources” web page for concise information and simple projection tools you can use to plan for future climate and sea level conditions.
Recognize the contribution an individual project can make to the community-at-large.

Resources

USGBC, RELi rating system:

https://www.usgbc.org/resources/reli-20-rating-guidelines-resilient-design-and-construction

US Resiliency Council: https://www.usrc.org/

EERI, Earthquake Engineers Research Institute: https://www.eeri.org/

American Institute of Architects (AIA)

Understanding resilience – AIA

Hazard mitigation design resources – AIA

Climate change adaptation design resources – AIA

How to integrate resilience into your practice – AIA

AIA Architect’s Guide to Business Continuity https://www.aia.org/resources/6282340-architects-guide-to-business-continuity

Citations/References

National Center for Environmental Information (NCEI), National Oceanic and Atmospheric Administration (NOAA) Disaster and Risk Mapping | Billion-Dollar Weather and Climate Disasters | National Centers for Environmental Information (NCEI) (noaa.gov)
Disaster Declarations by State and County Disaster Declarations for States and Counties | FEMA.gov
EERI Conference 2020, Workshop – EERI Learning from Earthquakes: Resilience Lessons from Reconnaissance Over Time, Andrew Makdisi – Environmental Effects, https://www.eeri.org/about-eeri/news/4294-952020-annual-meeting-and-nec-to-host-largest-seismic-design-competition
“Building Codes Save: A Nationwide Study. Losses Avoided as a Result of Adopting Hazard-Resistant Building Codes,” FEMA, November 2020 https://www.fema.gov/emergency-managers/risk-management/building-science/building-codes-save-study
(Amy Myers Jaffe, 2021). as reported in AIA Disaster Assistance Handbook, Third Edition, https://www.aia.org/resources/71636-disaster-assistance-handbook
National Institute of Building Science (NIBS) Study full report Natural Hazard Mitigation Saves 2019 Report (nibs.org)

Brace and Bolt Grants: https://www.earthquakeauthority.com/Prepare-Your-House-Earthquake- Risk/Brace-and-Bolt-Grants

Things YOU can do to help with the Climate Emergency

November 10, 2021| What you can do right now| AIA California

You may have heard as AIA CA shouted from the green rooftops that the time is NOW to declare a climate emergency. That’s right, AIA CA AIA officially declared a climate emergency. And now, we call on every member of our profession, and our allies, to make an immediate meaningful impact to de-carbonize the built environment.

For an easier digestion of what that means exactly, our leaders developed this bulleted guide. Take a look and see where you and your firm fits into saving the environment.

Energy model all of your projects to pinpoint areas of improvement.
Prioritize passive design to reduce costs and improve building performance.
Advocate for code changes to make responsible climate design and construction a requirement.
Electrify everything to lower emissions and cost, and increase efficiency, resiliency and safety.
Encourage existing building reuse and retrofit to decrease emissions.
Sign on to the AIA 2030 Commitment to show your dedication to reaching carbon neutrality, and track your progress.
Understand Energy Use Intensity to evaluate your designs and make change.
Increase your climate knowledge through the AIA California Climate Webinar Series.

Things You Can do Now: Energy Modeling

July 29, 2021| AIACA, Climate Action, What you can do right now| AIA California

What Is An Energy Model?

In essence, an energy model is a set of computer-generated calculations that help designers compare design options and predict anticipated energy consumption of a building and its systems. As technologies have advanced, so has the ability to analyze various aspects of building performance, either with general purpose “whole building” energy modeling packages or software developed for a specific purpose be it daylighting, ventilation, thermal bridging, occupant comfort, or another parameter. The modeler inputs data describing aspects of the building and external design conditions and the “calculation engine” drives the output. Building professionals can then analyse the output to make meaningful comparisons of different design options or compare whole building performance against a benchmark or targeted energy use intensity (EUI).

Why Is An Energy Model Important For Design Excellence?

Many architecture and engineering firms consider modeling a necessity in the design process. Performance modeling increases the ability to make informed decisions to improve energy performance, increase thermal and visual comfort, and improve building durability, among other design issues key to design excellence.

Some practitioners’ experience with modeling is solely as a tool used in the performance approach to document compliance with an energy code, or as a tool used for third-party certification such as USGBC LEED. It is important to understand that a compliance model is not intended to be a precise, predictive model of post-occupancy energy performance. Codes typically set a floor for allowable energy performance and a compliance model documents that the minimum level of performance has been achieved. This approach usually brings the energy model into the process at a point where it is too late to provide much design feedback. Thus, the model does not help designers understand scenario interactions with potentially positive or negative consequences. While compliance modelling is valuable for tracking certain energy metrics and achieving project milestones, modeling for design excellence goes beyond compliance.

Who Does the Performance Modeling?

Modeling can get complicated, but it doesn’t have to be! Make a plan and incorporate modeling in the project timeline. Effective use of modeling requires the architect or team to identify questions you need to ask, the level of detail needed to answer them, and the point in the process when the answers are required to facilitate a design decision. Identify who on the design team has the required expertise and is responsible for each of the different analyses needed to answer key questions. The team should agree upon the software tool, or in some cases tools, that will be used by the responsible parties.

The architect’s role is often to lead the process by knowing enough to have useful and collaborative discussions with those with expertise in specific areas, rather than doing their own energy modeling. However, this isn’t always the case. The AIA publication The Architects Guide to Building Performance draws a distinction between ‘single aspect’ and ‘whole building’ simulation. Single aspect analysis such as a massing or window shading study can often be done by a knowledgeable architect. Whole building analysis very early in design can also sometimes be performed by an architect. Certain software permits an architect to describe the enclosure while choosing among general approaches to electric lighting and HVAC systems that include default assumptions. The results are best thought of as providing a ranked order of the performance of different façade design options under consideration than as an accurate prediction of performance. This is still very valuable information!

When greater precision and information on HVAC and lighting systems is needed, an engineer or outside modeling consultant is needed. It is important to discuss the various assumptions the modeler must make about plug loads, occupancy patterns, and building operations.

What Are The Impacts Of Energy Modeling?

Energy models allow for optimization without compromising design. Early energy analysis can identify how even small changes in building massing, orientation, window-to-wall ratios, glazing types, insulated wall assembly, and more can have large impacts on building heating and cooling loads. These loads directly impact the size of the mechanical equipment, the size of the mechanical rooms, and the size of the utility bill. Façade appearance iterations including external shading elements can be studied along with their efficiency implications. These are just two examples of how results from an energy model can affect design.

Energy modeling also supports project cost management. A model improves the ability to compare first cost and operational cost payback periods for alternative façade or wall assembly options and HVAC, structural, and lighting systems. All clients are likely to choose a slightly more expensive and more efficient system when the payback is quick. Models make it possible to better understand the cost, or savings, of improved indoor air quality and occupant comfort.

Energy modeling also allows designers to push the envelope with less risk, adding an element of predictability to the process. Engineers can right-size building systems and equipment, reducing material resources and energy use while managing construction cost. Through energy modeling designers can identify specific best practices, compare a design to other projects in or outside of a firm, and compile and track firm progress on climate action through programs such as AIA’s 2030 Commitment. If building information modeling (BIM) software was used to develop the design the same digital model can sometimes be used for energy modelling by consultants. If architects plan to share their model, they should discuss model construction requirements with the consultant beforehand. This will reduce the need to revise or recreate the model for performance analysis.

What Is The Cost Of Energy Modeling?

The cost of a performance energy model can be split into three different categories: software, labor, and timing. The energy modeling world is full of both free-to-use and paid software, with the main difference being the support available. High quality free software is available from the US Department of Energy and university researchers, but with little support. Commercial software often includes support or support can be purchased for a fee. Whether free or paid, whole building energy software takes time to master. If you don’t have that time, work with a consultant.

The timing and the precision required of an energy model is part of the cost equation. Analysis performed by a skilled modeler early in schematic design can have a big impact with very little cost. Comparing the energy implications of different approaches to siting, massing, and window-to-wall ratio can often be done in an hour or two. More precise modeling later in the process takes more time. Even then, there are numerous examples where the cost of energy modeling was paid back in savings in first cost of equipment or through operational savings captured in a matter of months.

The old adage “Garbage In = Garbage Out” applies here. Models are only as good as the data that is provided, which means the designer and modeler must be in sync if they are not the same person. Base knowledge, clear communication, patience, and perseverance are mainstays of the energy modeler, whether inside an architect’s firm or hired as a consultant.

What You Can Do Now

If you’ve never used an energy model before, the first step is to commit to using one on your next project. It’s ok to start simple, with one key variable to test.
Add an energy model to your list of deliverables (and into your fees), if not for your client then for yourself.
Integrate energy modeling early in the design process when it need not be expensive and when you can get a lot out of it.
Set project performance goal and benchmarks: a certain EUI, a certain % better than code, etc. Use these to decide what questions you want the energy model to answer about your design. See AIA’s 2030 Commitment.
Treat your engineers and modelers as integral members of the design team. Ask them for recommendations to improve performance. They may see an opportunity that you do not. Your job isn’t to follow every recommendation but to meet the various design requirements while integrating excellent performance.
If you are currently working with an energy modeler to document compliance, ask if they could provide additional non-compliance modeling services earlier in a project.

Tools and Resources

Architect’s Guide to Building Performance: Integrating Simulation into the Design Process

http://content.aia.org/sites/default/files/2019-06/AIA_BPSGuide_2019_FINAL.pdf

Nonresidential Focus: The Shockingly Short Payback of Energy Modeling

https://www.energy.gov/eere/buildings/articles/shockingly-short-payback-energy-modeling

Climate Consultant Software, Energy Design Tools, https://energy-design-tools.sbse.org
Building Energy Software Tools Directory – An extensive list for knowledgeable practitioners.

https://www.buildingenergysoftwaretools.com

Colin Skinner is a senior energy modeler at Buro Happold’s Los Angeles office.

Leigh Christy, FAIA, LEED AP BD+C, is a Principal in the Los Angeles office of Perkins & Will.

Things You Can Do RIGHT NOW: Passive Design

April 28, 2021| AIACA, What you can do right now| AIA California

Authors: Bill Burke & Elena Nansen

Things You Can Do RIGHT NOW: Passive Design

This short article on Passive Design is next in the series, What you can do RIGHT Now. This article is specifically for a practitioner who is looking for pragmatic guidance on immediate steps to embrace contemporary passive design strategies.

What is Passive Building Design?

Contemporary passive design relies on understanding climate and taking advantage of siting, form, detailing, and construction assemblies to create buildings that achieve design excellence while reducing the need for energy consuming equipment to provide comfort and health. Reducing the need for energy makes it possible to downsize HVAC equipment, shorten operating times and seasons, shorten duct runs and, in some cases, eliminate equipment entirely. Passive design can mean shifting first cost from equipment to improvements to the building enclosure. Passive design requires focusing on the architecture first, before supplementing with active systems.

Passive design was an essential aspect of all building design until well into the 20th century as there were few alternatives to provide a more comfortable environment. With limited energy sources and technologies, architects and builders needed to understand the local climate and the thermal properties of regionally available building materials.

Climate & Daylight

Passive design starts with climate. Climate will influence orientation, shading, air movement, siting, and materials, among other things. Providing controlled daylight and enabling users some control over natural ventilation, when conditions and building type permit, are almost always preferred design strategies because they create pleasing spaces that connect building occupants to nature. Access to daylight is recognized as an essential element of human health and regulation of circadian rhythms.[i] While LEDs have reduced energy loads from electric lights, controlled daylight is always desirable and electric lights that are dimmed or switched off in response to daylight still save energy.

What’s Changed?

The 1970s saw the growth of passive solar design in response to resource shortages and other environmental concerns. Passive solar emphasized direct solar gain through expansive, seasonally-shaded, south-facing glass with internal thermal mass used for heating and cooling. Improvements in technology, insulation levels, quality of construction, and better understanding of the importance of air infiltration and air sealing have resulted in significant rethinking of passive solar design strategies. A building enclosure designed, detailed and built to deeply minimize thermal bridging and infiltration, with moderate amounts of glazed wall area, can achieve excellent energy performance even with a suboptimal site or orientation. Major improvements to the enclosure permit greater variation from the bioclimatic ideal. It is important to understand that well-insulated, air-sealed buildings do require mechanical ventilation! This is confusing to those who assume every aspect of performance is to be passive, including the ventilation. Buildings can and should open to the exterior, operating in different modes in response to outdoor conditions.[ii] Well-insulated, air-sealed buildings can open to the exterior during moderate weather, but can achieve deep operational energy reductions while supplying filtered ventilation air when outdoor conditions are inhospitable.

Contemporary passive design strives to mechanically heat or cool the building with the smallest possible energy use when you can’t achieve comfort with operable windows, thermal mass, or stack ventilation. With the impact of climate change, which has led to higher temperatures and poor air quality from wildfires, this is more relevant and appropriate than ever. Passive design means designing buildings that are very ‘tight’, minimizing interior sources of poor air quality such as combustion appliances and off-gassing materials, and providing filtered ventilation with outside air. Improved building enclosures permit greater aesthetic freedom, while still achieving excellent energy performance.

Today, the Passive House movement represents the leading edge of Passive Building Design. Passive House Institute^[iii] was founded in Germany by Wolfgang Feist, inspired by super-insulated homes built in North America in the late 1970s.^[iv] In North America, the Passive House movement split into two groups in 2014 with modest variations in approach and requirements. The North American Passive House Network (NAPHN)^[v] remains affiliated with the German Passive House Institute. Passive House Institute US (PHIUS)^[vi] instituted climate-specific requirements developed in cooperation with the US Department of Energy and Building Science Corporation. The two Passive House standards in North America both call for a super tight enclosure and mechanical ventilation, among other requirements. The Passive House standards apply to both residential and nonresidential buildings and are best thought of as Passive Building Standards. Both standards require a series of blower door tests throughout the construction process to document that the targeted level of air sealing is actually achieved.

The principles of climate based design still apply. Elongating a building axis in an east/west direction makes it easier to control sunlight and daylight and supports occupant well-being. South facing roofs can shade windows and maximize effectiveness of installed solar electric systems, especially with inclusion of battery storage. Modest amounts of thermal mass in nonresidential buildings, on the interior side of insulation and protected from direct sun, can increase comfort by absorbing heat over the course of a day.

Things You Can Do Right Now to Use Passive Design in Architectural Practice

Follow bioclimatic design principles to ‘design with climate’. Implement pre-design climate research in order to better understand which bioclimatic design principles are applicable to your project.
Conduct early Daylight Analysis, to optimize (not maximize!) natural light coming into the space, while minimizing any unwanted heat gain by strategic window to wall ratios and shading devices. As a starting point, an analysis for Spatial Daylight Autonomy and Annual Sunlight Exposure[vii] can be performed with many commonly used architectural drawing tools, sometimes requiring a ‘plug-in’, or with a variety of lighting design tools.
Improve your knowledge of required control layers and their role in enclosure performance. Achieving continuity of control layers will not only improve energy performance, but aid in management of moisture and better durability^[viii]^,^[ix]^,^[x] while making it possible to downsize HVAC equipment.
Reduce thermal bridging through improved detailing of wall assemblies. During the design Quality Assurance/Quality Control process check for thermal bridging within project details.
Improve the air tightness of your buildings. To save energy and provide good indoor air quality, require careful air-sealing of all your projects. New buildings with ventilation cannot be too tight. In existing building renovation, short of gut-rehab, the goal is to reduce air infiltration. In project documents for new construction, set air-tightness targets. Require blower door tests during construction in all projects to confirm new construction targets are achieved and to assess percentage reduction in renovation of existing buildings. [xi] [xii]
Separate mechanical heating and cooling from ventilation.[xiii] Even when you have eliminated the need for heating or cooling by passively providing thermal comfort, occupants need fresh air for ventilation.
Incorporate building electrification, eliminating combustion appliances such as gas stoves, water heaters, and furnaces, to reduce greenhouse gas emissions while improving indoor air quality. Limit products and finishes with high VOC content, to reduce off gassing.
Include a drawing explaining your design intent and the basis of your design. Describe how enclosure design contributes to load reduction and proper HVAC system sizing.
Window locations, shading devices, and roof overhangs used for occupant comfort and included in compliance documentation should be specifically noted so they are not ‘value engineered’ out as the project advances or during construction.
Energy Modeling: Optimizing design for energy is most easily achieved when performance modeling occurs throughout the design process. There is no single approach to modeling that is applicable to all firms. The important task is to find a way to incorporate energy analysis into the design process for your firm and design team. Some design firms may have skilled staff who can perform selected energy modeling analyses in-house. Others may have relationships with engineering consultants who can deliver energy analysis at key points in design. The situation for small firms and individual practitioners obviously varies. Some may have the skills and interest to learn software and perform select energy analyses, while others will not. At minimum, ask the Title 24 Part 6 compliance modelers you use if they can provide additional analysis at key points in the process. If your compliance modeler cannot perform additional analysis find one who can. For more guidance see Architect’s Guide to Building Performance: Integrating simulation into the design process.[xiv]

Tools and Resources:

BC Housing (British Columbia, Canada) offers numerous residential design and construction guides. See https://www.bchousing.org/research-centre/library/residential-design-construction (accessed 09/16/2020).

Heat Recovery Ventilation Guide for Houses, RDH Building Science, https://www.rdh.com/wp-content/uploads/2017/07/HRV_Guide_for_Houses.pdf (accessed 09/16/2020).

Cladding Attachment Solutions for Exterior-Insulated Commercial Walls, RDH Building Science, https://www.rdh.com/resource/cladding-attachment-solutions-for-exterior-insulated-commercial-walls-guide/ (accessed 09/16/2020).

Building Envelope Thermal Bridging Guide, BC Hydro, https://www.bchydro.com/powersmart/business/programs/new-construction.html#thermal (accessed 09/16/2020).

How to Implement Passive Solar Design in Your Architecture Projects, Arch Daily, https://www.archdaily.com/900418/how-to-implement-passive-solar-design-in-your-architecture-projects (accessed 09/16/2020).Daylight Harvesting for Commercial Buildings Guide, UC Davis, https://cltc.ucdavis.edu/publication/daylight-harvesting-commercial-buildings-guide, (accessed 09/16/2020).

Details Green Book Passive House Design, Arch Daily, https://www.archdaily.com/771475/detail-green-books-passive-house-design (accessed 09/22/2020).

Climate Consultant Software, Energy Design Tools, https://energy-design-tools.sbse.org/.

Blower Door Tests: https://www.energy.gov/energysaver/blower-door-tests

[i] https://www.nigms.nih.gov/education/fact-sheets/Pages/circadian-rhythms.aspx

[ii] https://cbe.berkeley.edu/mixedmode/index.html

^[iii] Passive House Institute, https://passivehouse.com (accessed 09/04/2020).

^[iv] Allison Bailes, The Evolution of Passive House in North America, https://www.energyvanguard.com/blog/the-evolution-of-passive-house-in-north-america#blog-comments (accessed 09/04/2020).

^[v] NAPHN. https://naphnetwork.org (accessed 09/04/2020).

^[vi] PHIUS, https://www.phius.org/home-page. (Accessed 09/04/2020).

[vii] Kevin Van Den Wymelenberg, Alen Mahić, Annual Daylighting Performance Metrics, Explained, Architect Magazine, April 12, 2016. https://www.architectmagazine.com/technology/lighting/annual-daylighting-performance-metrics-explained_o (accessed 9/22/2020)

^[viii] Joseph Lstiburek, Building Science Insight 091: Flow Through Assemblies. https://www.buildingscience.com/documents/building-science-insights-newsletters/bsi-091-flow-through-assemblies (accessed 09/4/2020).

^[ix] Joseph Lstiburek, Building Science Insight 0939: Five Things. https://www.buildingscience.com/documents/insights/bsi-039-five-things (accessed 09/4/2020).

^[x] Jonathan Smegal, John Straube, Research Report -1014: High-R Walls for the Pacific Northwest–A Hygrothermal Analysis of Various Exterior Wall Systems. https://www.buildingscience.com/documents/reports/rr-1014-high-r-walls-pacific-northwest-hygrothermal-analysis/view (accessed 09/4/2020).

[xi] BUILDING AMERICA BEST PRACTICES SERIES Retrofit Techniques & Technologies: Air Sealing, 2010 https://www.energystar.gov/sites/default/files/asset/document/DOE_Air%20Sealing%20Guide%20for%20Contractos.pdf

[xii] BC Housing, Illustrated Guide to Achieving Airtight Buildings, 2017. https://www.bchousing.org/research-centre/library/residential-design-construction/achieving-airtight-buildings, (accessed 9/23/2020).

[xiii] John Straube, Building Science Digest-022: The Perfect HVAC. https://www.buildingscience.com/documents/insights/bsi-022-the-perfect-hvac (accessed 9/22/2020)

[xiv] Architect’s Guide to Building Simulation, American Institute of Architects, 2019. https://www.aia.org/resources/6157114-architects-guide-to-building-performance:41 (accessed 9/23/2020).

Authors: Bill Burke & Elena Nansen

AIA California Climate Action via Code Change

March 18, 2021| Climate Action, What you can do right now| AIA California

AIA California has made environmental stewardship and climate action central to its strategy and actions. Climate change requires urgent attention, a perspective that is supported by the fact that 1700 + governments around the world that have declared a climate emergency.[1] Considered through this lens, even something as seemingly mundane as code development takes on new importance. This shift was presaged in 2018, when the AIA’s Blue Ribbon Panel for Codes and Standards issued a groundbreaking report that outlines a bold new vision of building codes and standards as valuable design tools for a resource constrained and climate challenged future.[2]

Until recently, this connection between codes and climate action may have seemed somewhat abstract. Code development follows a step by step, carefully meticulous path; as a result, code change tends to be slow, incremental and very fine grained. Broad sweeping moves that might seem best suited for the rapidly escalating climate emergency are not typically part of code development. On the other hand, the code and regulatory environment impacts every building project from new to retrofit, from small to large, so a shift of the entire building industry toward a low and zero carbon framework by definition must intersect with code and regulatory development. In 2019, AIA California expanded its climate action agenda to address code changes. Two bold code change petitions were submitted to California’s Building Standards Commission on behalf of AIA’s 11,000 architect and allied professional members. In fall 2020, these two code changes began the long process of vetting, hearings, debate and refinement that will lead to the 2022 California Building Code. Following is a brief summary of these proposals.

AIA CA Code Change Petitions for the 2022 California Building Code ZEROcode integration into CalGreen: Developed by the nonprofit Architecture 2030 organization – a world leader in climate action innovation – the ZEROcode has recently been made part of the International Building Code’s Energy Conservation Code for 2022 as an optional appendix. AIA California has worked with Architecture 2030 on the creation of a California specific version of the ZEROCode. We have petitioned the California Building Standards Commission to make this a part of California’s codes for commercial construction via the 2022 California Green Buildings Standards Code (CalGreen). As proposed, this would be California’s first zero carbon compliance tool available as an option for local adoption.

Amendment of the California Existing Building Code to incorporate all three compliance paths that exist in the 2022 International Existing Building Code. The International Existing Building Code is unique among the ICC national codes in having a focus on flexibility, presenting users with three compliance paths from which to choose. Each of these paths — Prescriptive, Work Area, and Performance — lead to safe, code compliant buildings. Their differences allow design professionals to match the code path to the unique circumstances a particular existing building challenge can present. Like all ICC Codes, the IEBC has been developed over many years in a national open, transparent, consensus environment. Thus, its provisions are well vetted and are already in use across the United States. The California Existing Building Code does not include these options. This lack of code flexibility in California makes reuse and retrofit of our existing building stock less feasible due to higher costs and greater uncertainty. It also deprives us some of the benefits that come from updating, reusing and retrofitting existing buildings. AIA California is advocating for expansion of the CEBC to include all of IEBC’s provisions. This will encourage and support renewing and repurposing more of our existing building stock. The revised code will reduce greenhouse gas emissions by leaving intact vast stores of embodied carbon. It will also encourage California design professionals and their clients to leverage existing infrastructure, increase our housing stock, and boost local economies with well-paying jobs.

What You Can Do Now: We have provided the letter of support to the California Energy Commission relative to the Zero Code initiative to Peter Strait Peter.Strait@energy.ca.gov or to the CEC docket (docket@energy.ca.gov with reference to CalGreen 2022 Code).

Please send a letter of support for the expansion of the CEBC to: Emily.Withers@hcd.ca.gov and Michael.Nearman@dgs.ca.gov with cc to Mark Christian mchristian@aiacalifornia.org; or log on to the hearing on March 29^th here: California Existing Building Code Focus Group Meeting — March 29, 2021

Focus Group Agenda/Notice(PDF)

For more information and how to support this initiative via AIA CA’s robust COTE team, email hkrek@aiacalifornia.org Michael A. Malinowski, FAIA [1] https://www.theclimatemobilization.org/climate-emergency/ [2] Disruption, Evolution and Change: AIA’s Vision for the Future of Design and Construction. http://content.aia.org/sites/default/files/2019-06/ADV19_Disruption_Evolution_Change.pdf

What you can do right now: Electrify Everything

February 3, 2021| Climate Action, What you can do right now| AIA California

By: Scott Shell, FAIA, Henry Siegel, FAIA, Joel Stout, AIA

What is building electrification?

All electric buildings use electricity exclusively to run heat pumps, induction cooktops and other high efficiency appliances rather than burning natural gas in any form on site — in furnaces, water heaters or gas stoves.

Why is it important?

Buildings are responsible for about 25% of greenhouse gas emissions in California; two-thirds of this comes from burning fossil fuels. The proportion of greenhouse gas emissions from gas combustion will keep growing as California’s electric grid gets closer to its legislated goal of 100% clean electricity by 2045. All-electric buildings eliminate fossil fuel combustion on site and have many benefits:

Lower carbon emissions: All-electric homes reduce GHG emissions by half compared to a mixed fuel building in 2020.[1]
Less pollution: Fossil fuel combustion produces toxins–including nitrogen dioxide and carbon monoxide — leading to unhealthy air in many homes. California burns more gas in buildings than in powerplants, yet buildings have no pollution control and emit six times more NOX pollution than power plants.[2]
Lower construction cost: A heat pump provides both heating and cooling in one appliance and costs less than a furnace and an air conditioner. Eliminating gas piping, flues, and the gas meter further reduces costs. An all-electric new home in Los Angeles costs about $9,000 less to build than one with gas.[3]
Lower lifecycle cost: The life-cycle cost for an all-electric single or multi-family home is $200-$400 lower every year[4] than one with gas. The life-cycle costs for non-residential projects are usually lower–including for offices, academic buildings, and labs.[5]
Increased efficiency: heat pumps are 3-4 times more efficient than gas appliances. A gas furnace is 80-90% efficient, while a heat pump is 350% efficient.
Widely used: heat pumps are the same technology that is in refrigerators and air conditioners, they just include a reversing valve to move heat in both directions. Since 1970 more homes have been built with electric heat than with gas.[6]
Resiliency and safety: Gas appliances and propane tanks become dangerous sources of fuel during wildfire and earthquake events, leading to additional fires and explosions. Modern gas appliances have electronic ignition and controls and will not work during power outages. However, electrical equipment, when paired with on-site renewable energy and battery storage, can be designed to run when the grid is down.

What’s changed? – Hardware

Heat pumps: until recently gas water heaters and furnaces were more efficient than electrical appliances. With the advent of high efficiency heat pumps for space heating, water heating, and even clothes drying this is no longer true: electrical equipment is far more efficient and produces far fewer carbon emissions. If gas is eliminated completely, overall construction cost is lower since no gas infrastructure is installed.
Induction cooking: induction cooking heats cookware directly through magnetic induction. The experience of cooking is very similar to cooking with gas and nothing like cooking on older electric resistance cooktops; after personal experience with induction stoves, 90% of people report a positive impression.[7] With induction cooking temperatures can be quickly adjusted as with gas; there is no lag time. Induction cooking is even being adopted in commercial kitchens because of its advantages over cooking with gas.
The cost of photo voltaic systems continues to fall rapidly and currently ranges from between $2.50 to $3.30 per watt.[8]

What’s changed? – Utilities, Codes

The electric grid: in 2019 36% of California’s electricity came from renewable energy and 63% from non-fossil fuel sources.[9] The state’s Renewable Portfolio Standard increases to 60% by 2030 and 100% carbon free electricity by 2045.
New code requirements for on-site renewable energy will reduce the line loss associated with electric energy produced off site.
Can the electric grid handle all electric buildings?[10] California’s peak electric demand is due to air-conditioning in the summer. Most of the increased load due to building electrification comes in winter improving the utilization rate of the electric grid, which should lower cost.
PG&E, the largest publicly regulated utility in California publicly endorses electrification even though they supply both gas and electricity.[11]
Utility companies and Community Choice Aggregators[12] are offering 100% “clean” or renewable energy as on option, and, in many cases, as the default choice for their customers.[13] [14] [15]
Gas leakage: new research has shown that the amount of gas that leaks from gas distribution systems, and the carbon emissions associated with these leaks, are many times higher than previously thought.[16] [17]
Code changes: Codes are being revised to eliminate earlier rules that gave preference to gas equipment (when it was the better choice.) Upcoming code revisions will include preferences for all-electric buildings.
Reach codes: Over 30 jurisdictions throughout the state have passed reach codes that prohibit the use of gas or require higher levels of energy efficiency for buildings using gas in new structures.[18]

What you can do right now!

If you are designing a new building, work with your engineers to analyze and propose all-electric equipment and appliances rather than gas equipment and appliances.
If you are rehabilitating existing buildings analyze the costs of “fuel switching” to all electric equipment. This may be limited by the size of the electrical equipment, but rebates are available for fuel switching.
Assist local jurisdictions in passing reach codes that mandate all electric construction for new buildings

Additional Tools and Resources: