The 2019 edition of the California Green Building Standards Code, also known as CALGreen, took effect at the beginning of this year. Its goals include:
- reducing greenhouse gas emissions from buildings
- promoting environmentally responsible, cost-effective, and healthier places to live and work
- reducing the consumption of energy and water.
CALGreen covers aspects of building design and construction that range from energy to water conservation to environmental quality. Much of it relates to building operation rather than construction. For example, most of the energy efficiency provisions relate to HVAC (heating, ventilation, and air conditioning), appliances, solar energy, and parking for bicycles and electric cars. Similarly, the provisions for water conservation relate primarily to plumbing fixtures. This blog, however, focuses on concrete.
A brief history of CALGreen
2008: The first version of CALGreen included only voluntary measures, which did not have the force of law.
2010: The first mandatory measures for residential and nonresidential construction included a 20% reduction of indoor water use and a 50% reduction in construction waste. In addition, there were requirements for a waste management plan, temporary construction ventilation, and finish materials.
2013: This edition clarified and expanded requirements for water efficiency and conservation, demolition, and recycling.
2016: This edition added requirements for charging stations for electric vehicles, organic waste, and water conservation.
2019: The current edition clarifies and updates previous requirements.
The purpose of this code is to improve public health, safety, and general welfare by enhancing the design and construction of buildings through the use of building concepts having a reduced negative impact or positive environmental impact and encouraging sustainable construction practices in the following categories:
- Planning and design.
- Energy efficiency.
- Water efficiency and conservation.
- Material conservation and resource efficiency.
- Environmental quality.
—California Green Building Standards Code section 101.2
Planning and design
The provisions of this chapter outline planning, design, and development methods that include environmentally responsible site selection, building design, building siting and development to protect, restore, and enhance the environmental quality of the site and respect the integrity of adjacent properties.
—California Green Building Standards Code section 5.101.1
During construction, prevention of stormwater pollution includes limiting soil erosion and controlling wastewater. To that end, the National Ready Mixed Concrete Association offers instruction on washout of concrete trucks. Manhattan’s Big U is a large-scale project designed to protect the island from flooding. It incorporates landscaping and development to meet the goals of sustainability and enjoyment.
Material conservation and resource efficiency
The provisions of this chapter shall outline means of achieving material conservation and resource efficiency through protection of buildings from exterior moisture, construction waste diversion, and employment of techniques to reduce pollution through recycling of materials and building commissioning and adjusting or testing and adjusting.
—California Green Building Standards Code section 5.401.1
CALGreen requires the reuse, recycling, or salvage of at least 65% of the waste from construction and demolition. Pages 89 through 94 of the guide provide a template to help you develop a construction waste management plan for your project. The template includes a spreadsheet for evaluating how and how much of each type of material on the jobsite you will divert from landfills. You must communicate the plan to all of your subcontractors, who must also comply with it.
The provisions of this chapter shall outline means of reducing the quantity of air contaminants that are odorous, irritating, and/or harmful to the comfort and wellbeing of the building’s installers, occupants and neighbors.
—California Green Building Standards Code section 5.501.1
Paints, coatings, adhesives, sealants, and caulking materials must comply with the relevant regulations on volatile organic compounds (VOCs). If you use colored concrete with textured or polished surfaces, you can avoid many of these materials altogether. And the finished concrete surfaces will not need repainting—ever. In addition, forgoing flooring materials in favor of bare concrete means you won’t have to replace flooring that wears out.
CALGreen allows limited use of the building’s permanent HVAC system to control air pollutants during construction. However, you must replace air filters prior to occupancy or at the conclusion of construction, whichever is later.
Reducing greenhouse gas emissions
By any measure, California’s push to reduce greenhouse gas emissions has been highly successful. In its press release of July 11, 2018, the California Air Resources Board noted how well the state had reduced greenhouse gas emissions. Some highlights from the state’s annual emissions inventory included:
- Carbon pollution dropped 13% statewide since a 2004 peak, while the economy grew by 26%.
- Per capita emissions, which were among the lowest in the country, fell 23% from a peak of 14.0 metric tons per person in 2001 to 10.8 in 2016.
- Carbon pollution dropped 3% between 2015 and 2016, which is comparable to taking 2.4 million cars off the road or saving 1.5 billion gallons of gasoline and diesel fuel.
- The “carbon intensity” of California’s economy—that is, the amount of carbon pollution emitted per $1 million of gross state product—dropped 38% since the 2001 peak to about half the national average.
- California produces twice as many goods and services for the same amount of greenhouse gas emissions as the rest of the nation.
Voluntary measures in CALGreen 2019
In addition to the above requirements, CALGreen 2019 includes some voluntary measures. Why would you want to go beyond the requirements? As CALGreen has evolved, what begins as a voluntary measure may become a requirement in a later edition. If nothing else, what you learn from taking voluntary measures may be helpful on future projects. Also, some jurisdictions may adopt these as part of their building codes, in which case it’s mandatory already. Here are some ideas to consider for concrete construction.
- Regional materials—that is, those harvested or produced within 500 miles of the jobsite—use less energy for transport than those imported from farther away. Traditional architecture could be a source of ideas for regional materials.
- Concrete offers several possibilities for recycled materials, including recycled aggregate, most supplementary cementitious materials, and wash water (conforming to ASTM C1602). You can even reuse fresh concrete.
- If the cement plant uses alternative raw materials, alternative fuels, or alternative power (for example, solar power purchased from the utility), that counts toward reducing greenhouse gas emissions.
- High-strength concrete may enable the designer to use less material overall, as smaller cross-sections and longer spans mean less concrete.
- Choose materials with enhanced durability and/or reduced need for maintenance, as determined by a life cycle analysis.
- CALGreen requires a construction waste reduction of 65%, but you can go further and reduce it by 80%.
- For a design life of 60 years, use a life cycle assessment (ISO 14044) to show that the building achieves at least a 10% improvement compared to a standard building meeting the 2019 code in at least three areas, one of which must be climate change:
- Climate change (greenhouse gases)
- Fossil fuel depletion
- Stratospheric ozone depletion
- Acidification of land and water sources
- Photochemical oxidants.
- Maintain indoor air quality during and after construction.
How can Beton help you meet the requirements of CALGreen?
‘I don’t believe you,’ he said to the Genie Iff. ‘How did he send the message? I’ve been right with him almost all the time.’
‘He sent it by the usual means,’ Iff shrugged. ‘A P2C2E.’
‘And what is that?’
‘Obvious,’ said the Water Genie with a wicked grin. ‘It’s a Process Too Complicated To Explain.’
—Salman Rushdie, Haroun and the Sea of Stories
If you need concrete with a high recycled materials content that still meets the performance requirements, we can design and specify it. High performance concrete—whether that means strength, durability, or aesthetics—is our main area of expertise.
We also have plenty of expertise in producing high-performance concrete. It’s not just theory to us; we know how to make it work on the jobsite.
We can also help with the life cycle assessment and life cycle analysis, which you’ll need if you want to quantify and document the benefits of the sustainability measures you’re taking.