July 24, 2018 Shakari McGill

CALGreen: An Introduction

Sustainability is best defined as creating and maintaining the conditions under which humans and nature can exist in productive harmony to support present and future generations  (Environmental Protection Agency , 2016). As the population grows, housing demand will follow suit; this concept has new life into many industries and their respective markets. Not only has the architecture field seen a push to include measures and products that curtail energy use, water use, and waste creation; the construction industry has seen policy change to be more environmentally conscious when building as well. With construction of a building accounting for 50- 60% of its lifetime energy use, it is paramount that  enforceable policies like the California Green Building Standards Code  (CALGreen) exist to mediate this use and ease stress on the balance of the environment. The fact that these codes are regularly revised and updated is also extremely beneficial to the environment.

CALGreen is a California-specific building code; it is part 11 of the California building energy efficiency standards know as Title 24. The code itself consists of a base level and two additional tiers. . Part of CALGreen’s base level mission entails dampening the impact of construction on the environment through the preservation of site slopes, drainage mitigation, and careful planning to mitigate negative effects on neighboring areas (California Energy Commission, 2016). Tier 2 provides a higher degree of sustainability by requiring buildings to exceed the most current edition of “Savings by Design Modeling Procedures” by a measure of 15% of higher (International Code Council, 2017).

CALGreen is not meant to be rigid and limiting; this type of policy is intended to be adaptive; to grow and change in three-year intervals. This is driven by responses to new research and industry, and is built incrementally upon previous improvements, allowing the market to catch up. It ensures that construction is executed in the most sustainable way possible. Some changes CALGreen will see in 2019 are:

  • A new measure requiring all multifamily housing construction to comply with CALGreen (as compared to the 17-unit requirement of the previous iteration)

In 2018, Verdical Group worked on a high-profile Tier 1 residential project; had this project been permitted in 2019, it would have seen elevated energy savings from the inclusion of a DWHR system (California Energy Commission, 2018).

By Using CALGreen as a starting point, more and more projects in California are leveraging their initial sustainable efforts dictated through CALGreen to pursue additional sustainability measures and initiatives . Such measures/initiatives include Leadership in Energy and Environmental Design (LEED), National Green Building Standard (NGBS)(ICC-700), and the WELL Building Standard (WELL). LEED v4 is a broadly applicable rating system that encompasses various structure types. Sustainable methods for construction are covered in LEED v4 as well. The National Green Building Standard (NGBS)(ICC-700) is a self-declared alternative to LEED that focuses on site development, water conservation, material resource efficiency, energy efficiency, indoor air quality, and maintenance (National Multifamily Housing Council, National Apartment Association , 2015).

WELL focuses on the health and well-being of building occupants, putting emphasis on the effects of air quality, task lighting, and thermal comfort on productivity (International WELL Building Institute , 2018). Overlap between CALGreen and LEED measures exists in water efficiency, sustainable sites, and materials & resources categories. For WELL, there is overlap with CALGreen in the energy efficiency category. Overlap in NGBS occurs in site development – specifically drainage mitigation. Due to the relative ease and compatibility of CALGreen with these other initiatives, 14% of California’s building portfolio consists of green buildings (Burgoyne, 2015).

Increasing demand for housing has created a push for a plethora of new construction. Sustainable controls for this new construction have become a must because of market pressures and environmental concerns. Adaptive measures such as CALGreen and others aim to regulate aspects of projects such as energy utilization, water consumption, and waste creation as their impacts grow and change. As CALGreen evolves it will continue to do so more efficiently and provide a great foundation for other initiatives (such as LEED) to further strengthen a project’s sustainability. CALGreen and other sustainable controls are the key to market prosperity and environmental longevity.


For Further information:

Review The CALGreen building code in its entirety here:


Get a more in-depth understanding of how the California Energy Commission tracks energy use for the state here: http://www.energy.ca.gov/renewables/tracking_progress/documents/statewide_energy_demand.pdf

This document from the university of Michigan provides a statistical representation of the increase in demand for housing:





Burgoyne, D. (2015). State of California buildings focus on water, energy, environment, performance. Retrieved from LEED: https://www.usgbc.org/articles/state-california-buildings-focus-water-energy-environment-performance

California Energy Commission. (2016). BUILDING ENERGY EFFICIENCY STANDARDS FOR RESIDENTIAL AND NONRESIDENTIAL BUILDINGS. California : California Energy Commission.

California Energy Commission. (2018). CASE Report Drain Water Heat Recovery. California: California Energy Commission.

Environmental Protection Agency . (2016, October ). Learn about Sustainability . Retrieved from EPA: https://www.epa.gov/sustainability/learn-about-sustainability#what

International Code Council. (2017). Guide to the 2016 California Green Building Standards Code. California : International Code Council.

International WELL Building Institute . (2018). WELL v2. Retrieved from WELL: https://v2.wellcertified.com/v2.1/en/overview

National Multifamily Housing Council, National Apartment Association . (2015). Building Codes and Standards: Green Building Overview. Washington D.C.

TCP. (2018). The Amp. Retrieved from TCP: https://www.tcpi.com/green-standards-certifications-multifamily-housing/






To achieve CALGreen Tier 1, buildings must comply with the latest edition of “Savings By Design, Healthcare Modeling Procedures”.[2] To achieve CALGreen Tier 2, buildings must exceed the latest edition of “Savings By Design, Healthcare Modeling Procedures” by a minimum of 15%.[3]

The provisions of this code are directed to: