Regulatory Trends Related to MEP in Southern California

The field of mechanical, electrical, and plumbing (MEP) engineering is constantly evolving, with regulatory trends shaping the industry in Southern California. As a result, MEP engineers must remain up to date with the latest regulations to ensure that buildings are designed to be safe, efficient, and environmentally friendly. In this blog, we will discuss some of the regulatory trends related to MEP in Southern California, with a focus on energy efficiency, water conservation, indoor air quality, fire safety, and green building regulations.

Energy Code Changes

Electrical Code Changes

The California Energy Commission has updated sections of the California Electrical Code to include additional energy efficiency-based electrical requirements that are applicable to various systems. These include electrical power distribution systems, panelboards in single-family and multifamily buildings, and electric appliances such as heat pump water heaters, electric cooktops, and electric clothes dryers. In addition, the amendments include new electrical requirements for energy storage systems (ESS) and their electric readiness in multifamily buildings. The changes to the code are intended to assist code users in identifying the applicable energy efficiency requirements in the California Energy Code.

The amendments are found in various chapters of Part 3 of the California Electrical Code, which outlines requirements for electrical systems in commercial and industrial buildings. As well as amendments which relate to panelboards and electric appliances in single-family and multifamily buildings. Other amendments include those from the Housing and Community Development, the State Fire Marshal, and the Office of Statewide Health Planning and Development. These changes range from defining new requirements for equipment to be approved for use to allowing battery systems to be used as an alternate power source.

Mechanical Code Changes

The California Mechanical Code has undergone several changes to various chapters and sections. These changes have been implemented by different state agencies, including the Building Standards Commission, State Fire Marshal, California Energy Commission, Department of Housing and Community Development, and the Office of Statewide Health Planning and Development.

Among the notable changes is the amendment to permit expiration in Chapter 1. This change stipulates that permits will expire after 12 months instead of the previous 180 days. It also allows for permit extensions, except when the work authorized has been abandoned. Another significant change is in Chapter 4, where a new code section requires all air distribution devices and supply air outlets to meet ASHRAE 170-2013, to address the prevention of disease-causing microorganisms in mechanical systems.

In Chapter 11, State Fire Marshal added exceptions to allow the use of A2L refrigerant in specific self-contained factory-sealed air conditioning units. Additionally, in Chapter 12, the California Energy Commission added new code sections to reference California Energy Code requirements for pipe insulation and additional insulation requirements for heated slab floors. These changes are intended to align the California Mechanical Code with current regulations, improve energy efficiency, and ensure compliance with health and safety standards.

Plumbing Code Changes

The California Plumbing Code (CPC) – Part 5 has undergone several changes in the 2022 code cycle. The changes include modifications in permit expiration, clarification of water fixture standards, and identification of additional energy efficiency requirements applicable to water heating systems and pipe insulation. The permit expiration has been changed to 12 months with an allowance for permit extensions, reflecting the requirements of Assembly Bill 2913.

The plumbing fixture standards have been revised and include several modifications and revisions for determining plumbing fixture count minimums. Chapter 15 of the California Plumbing Code has been amended to provide clarification on the application of Section 1505 to landscape irrigation systems that use recycled water and to add an exception for the use of a swivel ell or changeover device for supplying potable water during an interruption in recycled water service. The CPC has also amended sections to clarify the interaction between standards for plumbing fixtures and fittings that are subject to regulation as water-using appliances and the plumbing systems specified in adopted model code language. Lastly, the code has added new sections and made revisions to clarify the applicability of CPC standards to landscape irrigation systems using recycled water, and a new reference standard has been added for water treatment equipment for hemodialysis applications.

2022 Building Energy Efficiency Standards for Single Family Residential

The 2022 Building Energy Efficiency Standards (Energy Code) for single-family residential buildings introduces a single fuel prescriptive heat pump baseline for either water heating or space heating, and significant changes in indoor air quality (IAQ) requirements. Other new requirements include new roof deck insulation maximum area-weighted average U-factor requirement, changes in hot water piping language, and new lighting requirements. There are also updates for additions and alterations, and changes to requirements for ducts in conditioned space, gas water heater installations, central fan integrated ventilation systems, and vented kitchen range hoods. New energy design rating metrics have been added, and prescriptive compliance includes space heating and water heating equipment requirements based on the climate zone.

Here are some additional examples of changes to the 2022 Building Energy Efficiency Standards for single-family residential buildings:

  • The energy design rating (EDR) metrics have been updated. Compliance now requires separately meeting EDR1, efficiency EDR2, and total EDR2.
  • Space heating equipment must be a heat pump in certain climate zones, and in other climate zones it can be either a heat pump or a gas heating system.
  • Water heating equipment must be a heat pump water heater meeting certain criteria or a solar water heating system with electric backup.
  • Vented kitchen range hoods require ventilation rates or capture efficiencies based on conditioned floor area and fuel type.
  • New requirements for central fan integrated ventilation systems requiring a motorized controlled damper, damper controls, and variable ventilation.
  • Ducts in conditioned space do not require insulation if specific criteria are met, and ducts are located entirely inside the building’s thermal envelope.
  • For HVAC duct alterations, duct leakage testing is now triggered when more than 25 feet of ducts are replaced or installed.
  • New requirements for energy storage system (ESS) readiness, including interconnection equipment or a dedicated raceway, a minimum of four branch circuits, a minimum busbar rating of 225 amps, and space for future installation of a system isolation equipment or transfer switch.
  • New electric readiness requirements for space heating, cooking, and clothes dryers when gas equipment is installed. Electrical infrastructure must be provided and reserved to the equipment location for the future installation of electrical appliances.

These changes and others are intended to improve energy efficiency and indoor air quality while providing greater flexibility for builders and homeowners.

2022 Building Energy Efficiency Standards for Multifamily

The 2022 Energy Code has combined low-rise and high-rise multifamily buildings into one type and moved all the requirements to their own subchapters. The code also updates definitions for multifamily buildings and makes changes to mandatory requirements for various equipment types, such as minimum HVAC efficiency requirements and new requirements for central fan integrated ventilation systems.

Additionally, the code has new requirements for communal pool and spa systems, unified envelope insulation, vapor retarder, and fenestration requirements, and updated water heater piping and indoor/outdoor lighting requirements. The code has also added new photovoltaic (PV) and battery storage requirements for specific building types and created new electric ready requirements for space heating, cooking, and clothes dryers when gas equipment is installed. Finally, there are unified requirements for alterations and additions, including updated insulation and lighting requirements, altered fenestration efficiency requirements, and new IAQ and mechanical exhaust requirements.

2022 Building Energy Efficiency Standards for Nonresidential

The 2022 Building Energy Efficiency Standards (Energy Code) has made major changes to nonresidential and hotel/motel building requirements. The most significant changes are in photovoltaic (PV) and energy storage system requirements, a prescriptive heat pump space-conditioning baseline for certain climate zones, requirements for Dedicated Outside Air Systems (DOAS), and the addition of new covered processes, including controlled environment horticulture spaces. The Energy Code also includes changes to administrative regulations, envelope requirements, indoor and outdoor lighting, mechanical and water heating, and electrical power distribution.

Some of the key changes are:

  • Lighting controls and mechanical systems acceptance test technician certification providers must record related Certificates of Compliance, Installation, and Acceptance Testing in an electronic database.
  • New prescriptive requirements added for PV and battery storage systems for specific building types. Energy Commission-approved shared solar PV, other renewable electric generation system, or ESS may be used to meet PV or ESS requirements using the performance method.
  • Prescriptive metal-framed wall U-factor maximums decreased in all climate zones. Vertical glazing efficiency values are more stringent and now climate zone dependent for fixed windows, curtainwalls, and storefronts.
  • New mandatory occupant sensing control requirements for office spaces greater than 250 SF. Automatic daylighting controls for secondary side lit daylit zones is now mandatory.
  • Minimum heating, ventilation, and air conditioning efficiency requirements updated for various equipment types. Minimum efficiency requirements added for dedicated outside air systems (DOAS), air conditioners serving computer rooms, and heat pump and heat recovery chiller packages.
  • New mandatory requirements for compressed air systems regarding monitoring, leak testing, and pipe sizing. New mandatory requirements for controlled environment horticulture systems regarding dehumidification, lighting, electrical power distribution, building envelope, and space conditioning.
  • New prescriptive requirements for computer rooms regarding refrigerant economizer coefficient of performance, design load thresholds, and uninterruptible power supply (UPS) efficiency.
  • Overall, the 2022 Building Energy Efficiency Standards will require new buildings to incorporate more efficient systems and technologies, with a focus on reducing energy use and greenhouse gas emissions.

Summing Up

As an architect, commercial designer, general construction contractor, building owner, or commercial real estate professional in Southern California, it is critical that you are aware of the regulatory trends related to MEP. Compliance with these regulations ensures that the buildings you create are safe, efficient, and environmentally responsible. These features not only benefit the occupants but also contribute to a more sustainable and resilient society, which is essential for the future of our planet.

The regulatory trends related to MEP in Southern California reflect a growing awareness of the need for sustainable construction practices. MEP engineers play a critical role in this process, as they are responsible for designing the systems that ensure a building’s functionality, safety, and comfort. By complying with these regulations, MEP engineers are helping to create buildings that are not only environmentally friendly but also cost-effective and resilient. These regulatory trends are part of a larger movement towards sustainability and environmental consciousness in the built environment.

To make the most of these trends mentioned above and to learn more about how you can ensure compliance with these regulations, seek the help of professional MEP engineers. Pro Engineering Consulting, Inc. specializes in MEP engineering consulting. Contact our experts with questions about your next construction project.


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