The concept of a tiered building code is simple to understand - the higher the tier, the better the energy performance of the building.

At each tier, there will be prescribed energy efficiency targets or "steps" that must be met in order to comply with code. British Columbia is the first province in Canada to implement the tiered Step Code - the diagram below outlines how the tiers will apply to homes as the province moves toward the year 2030:

HOW ARE HIGHER TIERS ACHIEVED?

Over the coming years, building codes will increase energy efficiency requirements for new buildings and eventually, existing buildings will also fall under the same code mandated performance expectations. Little by little, all buildings will need to meet energy targets in the higher tiers of Step Code.

This means that buildings will need to follow one of two pathways:

• NEW - Energy modelled design and performance commissioning.
• EXISTING - Energy audits and prescribed improvements to meet code requirements.

TIERED CODE - NEW BUILDINGS

The preliminary stages of planning and energy modelling for new buildings will involve energy advisors and building science experts who can design the optimal building envelope and mechanical system strategies for the best possible energy performance.

This may include the following approaches:

• Super insulated assemblies;
• Super air tight enclosures;
• High performing windows and doors;
• Elimination of thermal bridges;
• Continuous mechanical ventilation;
• Renewable energy systems.
  

Energy efficiency programs like Passive House and Net Zero Energy Homes will play a prominent role in new homes of the future.

TIERED CODE - EXISTING BUILDINGS

There are millions of existing buildings in Canada, with a large percentage in need of major energy retrofit work. This process will involve energy advisors with experience in older buildings and energy audits to determine how the building is currently performing. From there, a strategy for improvements can be planned.

Those improvements may include some or all of the following:

• Additional insulation in attics, walls and basements;
• Improved air tightness and sealing;
• Upgraded HVAC systems with additional mechanical ventilation (HRV or ERV);
• Replacement windows and doors;
• Improved water management - flashing, eavestrough, site drainage;
• Renewable energy systems.
  

NOTE: The energy performance of older existing buildings will be difficult, if not impossible, to match with new construction targets. Instead, the expectation for performance will centre on measured improvements from the baseline, as opposed to a modelled target.