NECB 2020 and HVAC compliance

The National Energy Code of Canada for Buildings (NECB) sets minimum energy efficiency requirements for the design and construction of new buildings and additions. It is published by the National Research Council of Canada as a model code, which means it has no legal force until a province, territory or municipality adopts it. NECB 2020 is the current edition in use across much of Canada, although some jurisdictions still reference NECB 2017 or their own modified versions.

For HVAC designers and building owners, the NECB affects equipment efficiency, heat recovery, fan and pump power, controls, duct and pipe insulation, and the way whole-building energy performance is demonstrated. This guide summarizes the parts that matter most for mechanical systems. It is not a substitute for reading the code edition adopted by your authority having jurisdiction (AHJ).

How the NECB is organized

The NECB is divided into parts. The sections most relevant to mechanical design are:

Parts 3 to 7 each contain prescriptive requirements and, in most cases, a trade-off option. Part 8 provides the alternative of demonstrating compliance by energy modeling.

The three compliance paths

Prescriptive path

Every requirement in the relevant part is met as written. For HVAC this means meeting the minimum equipment efficiencies, fan power limits, heat recovery requirements, economizer requirements, insulation levels and control provisions in Part 5. It is straightforward to check but leaves no room to offset a shortfall in one area with a gain in another.

Trade-off path

Within a single part, a designer can show that a non-compliant element is offset by better performance elsewhere in the same part, using the methods defined in that part. For HVAC, trade-off options let you, for example, justify a system that does not meet one prescriptive item by demonstrating equivalent or better performance using the specified calculation procedure.

Performance path

Part 8 compares the modeled annual energy use of the proposed building against a reference building built to prescriptive requirements, using the same weather, schedules and operating assumptions. The proposed design complies if its energy use does not exceed that of the reference. Some mandatory provisions must still be met regardless of path. A building energy model is required, and the software and modeling rules must follow Part 8.

What is new in NECB 2020

NECB 2020 introduced a tiered performance structure. Tier 1 represents basic compliance with the code, and higher tiers require progressively greater improvement in energy performance over the reference building. The tiers give provinces and municipalities a ready-made path toward net-zero energy ready construction, since a jurisdiction can adopt a higher tier as its minimum or offer it as a voluntary target. Check which tier, if any, your AHJ has adopted.

The 2020 edition also updated many prescriptive values, including equipment efficiency tables aligned with current federal and provincial energy efficiency regulations, and refined modeling rules in Part 8.

Key HVAC requirements in Part 5

The exact values depend on the edition and climate zone, so verify against the adopted code. The main topics are:

• Equipment efficiency: minimum efficiencies for chillers, boilers, unitary equipment, heat pumps and cooling towers. Where federal or provincial efficiency regulations also apply, both must be met.
• Heat recovery from exhaust air: required for systems above defined thresholds of outdoor air and climate severity, with a minimum sensible heat recovery effectiveness. In most Canadian climates this captures a large share of new commercial air systems.
• Economizers: air-side or water-side economizers for cooling systems above set capacities, with integrated control so the economizer and mechanical cooling can operate together.
• Fan power limits: maximum allowable fan system power per unit of supply airflow, with adjustments for filtration, heat recovery and other pressure drops.
• Pumping: variable flow requirements for larger hydronic systems and limits on pump power.
• Controls: zone temperature control, automatic setback and shutdown, deadbands between heating and cooling, and limits on simultaneous heating and cooling.
• Duct and pipe insulation: minimum insulation levels by fluid temperature and location.
• Duct sealing: sealing requirements, and leakage testing for higher-pressure ductwork.
• Ventilation: outdoor air quantities set by the NBC and ASHRAE 62.1, with demand-controlled ventilation required in some high-occupancy spaces.

How provinces adopt it

Energy code adoption varies widely, and requirements can differ even between neighbouring municipalities.

• British Columbia uses the NECB alongside the BC Energy Step Code, which sets performance targets such as thermal energy demand intensity and total energy use intensity. Local governments may require higher steps.
• Alberta adopts the NECB through the Alberta Building Code framework, generally with few modifications.
• Ontario sets energy efficiency requirements through Supplementary Standard SB-10 of the Ontario Building Code, which references NECB and ASHRAE 90.1 with Ontario-specific provisions. Toronto adds its own green standard for many developments.
• Quebec has its own energy efficiency chapter in the Construction Code, based on the NECB with modifications.

For a closer look at regional differences, see provincial building codes and HVAC. Some jurisdictions also allow ASHRAE 90.1 as an alternative; the differences are covered in ASHRAE 90.1 vs NECB.

Common HVAC compliance problems

The items below come up repeatedly during permit review and commissioning:

1. Heat recovery omitted from small make-up air or exhaust systems that actually exceed the threshold.
2. Fan power exceeding limits because of high-pressure filtration, long duct runs or undersized ductwork, without using the allowable adjustments.
3. Economizer controls specified but not integrated, or locked out by sequences.
4. Packaged equipment selected on capacity alone, without checking that its rated efficiency meets the table for that size category.
5. Performance path models that assume controls (resets, DCV, setback) not actually included in the design documents.
6. Missing documentation: compliance forms, efficiency cut sheets and model reports that the AHJ expects with the permit submission.

Frequently asked questions

Does an existing building have to meet NECB 2020?

Generally only new construction and additions must comply. Alterations may trigger requirements for the replaced components, depending on the province and the scope of work. Ask the AHJ early.

Is NECB compliance the same as low energy use?

No. The code sets a minimum. Many buildings that comply still have substantial room for improvement, and the compliance model is not a prediction of actual utility bills.

Who signs off on compliance?

Typically the registered professional of record for the mechanical design, with the building official reviewing the submission. Commissioning helps confirm that the controls and equipment assumed for compliance were actually installed and work.

Key takeaways

• The NECB is a model code; it applies only where adopted, and the edition and amendments vary by jurisdiction.
• Compliance can be shown prescriptively, by trade-off within a part, or by whole-building modeling under Part 8.
• NECB 2020 adds performance tiers that jurisdictions can use to step toward net-zero energy ready buildings.
• Heat recovery, fan power, economizers, equipment efficiency and controls are the main HVAC compliance items.
• Design documents, models and installed controls must agree, or compliance on paper will not translate into performance.