Reducing emissions to complement energy efficiency

Like the BC Energy Step Code, the Zero Carbon Step Code is a flexible, predictable plan to improve new buildings over time, with the objective to reach zero emissions from all new buildings by 2030. It complements the BC Energy Step Code by reducing emissions while improving energy efficiency. Together, they make buildings that are cleaner, more energy efficient, and affordable to operate.

The Zero Carbon Step Code was first introduced in a May 1, 2023 update of the BC Building Code. It provides several options to reduce the amount of operational carbon emissions from a building by requiring lower emissions from space and water heating systems.

Carbon Performance Steps

Similar to the BC Energy Step Code, the Zero Carbon Step Code is based on different, measurable Steps. In general terms, these Carbon Steps can be referred to as:

• Moderate Carbon Performance (EL-2)
• Strong Carbon Performance (EL-3)
• Zero Carbon Performance (EL-4)

Local governments and other Authorities Having Jurisdiction may choose to incentivize or require builders to meet any Carbon Step of the Zero Carbon Step Code, including a “measure only” level. The text below show what the different compliance pathways look like for Part 9 and Part 3 buildings.

Two options for simple (Part 9) buildings

For buildings like single-family homes, rowhomes, or small apartment buildings, builders and developers may either follow a prescriptive or performance approach.

The prescriptive path requires builders to decarbonize energy-intensive appliances like space heating, water heating and cooking equipment. The higher the Carbon Step, the more decarbonized equipment will have to be installed.

The performance path sets overall greenhouse gas emission targets for each Carbon Step. Builders may choose from different metrics optimized for small, medium, and large-sized homes. Builders who choose this route can ask their Energy Advisor to calculate the impact of their mechanical system choices on the overall carbon performance of the home. Under the performance path, builders may still include some combustion equipment like fireplaces, cooktops, or clothes dryers and still comply with the top Carbon Step (“Zero Carbon Performance”).

One option for complex (Part 3) buildings

When building large residential buildings, offices, retail buildings, and hotels and motels, the Zero Carbon Step Code requires builders to follow a performance path that sets targets for a building’s greenhouse gas intensity (GHGi). Again, the energy model for each building may be used to include carbon intensity calculations. Space heating, cooling, ventilation, domestic hot water, cooking appliances and combustion fireplaces are included in this calculation. As Part 3 buildings vary in size, shape, and purpose, there are different performance targets for different building types. For detailed information, please see the BC Building Code.

Purpose

Until recently, the BC Energy Step Code was the main tool to reduce energy use and emissions from buildings. While energy efficiency typically reduces emissions by impacting the size, efficiency and consequently amount of greenhouse gas emissions from mechanical systems in a new building, it does not fully eliminate a building’s carbon emissions, even under most stringent energy efficiency requirements.

The Province and local governments have set ambitious greenhouse gas reduction targets that can only be achieved if the building sector starts to decarbonize.  The Zero Carbon Step Code provides a new tool for the construction sector and local communities to switch from carbon-intensive mechanical systems to zero carbon systems. The Province will start to mandate different Zero Carbon Step Code Levels as early as 2024, and require zero carbon new construction by 2030.

More guidance coming soon

The Energy Step Code Council is updating the Local Government Best Practices Guide, last published in 2019, to include new information regarding the Zero Carbon Step Code. In the meantime, many local governments have published information about the Zero Carbon Step Code and how it is being implemented in their community.