National Building Code 2025 - Net-Zero Energy Requirements for New Construction

Canada's construction sector is undergoing a fundamental transformation driven by updated national building codes. The National Energy Code of Canada for Buildings (NECB) 2020, developed by the Canadian Commission on Building and Fire Codes, establishes a clear pathway toward net-zero energy ready buildings by 2030—delivering 10-15% improved efficiency at baseline tiers and 60-70% improvements at the highest performance levels.

Understanding NECB 2020 Structure

Tiered Performance Framework

Unlike previous editions that set a single baseline, NECB 2020 introduces five performance tiers allowing provinces, territories, and municipalities to adopt progressively stringent requirements:

Tier 1: Baseline energy performance (reference standard)

10-15% more efficient than NECB 2017
Achievable with conventional construction practices
Expected to be adopted universally by 2025-2026

Tier 2: Enhanced efficiency (15-20% improvement over baseline)

Improved envelope specifications
Higher HVAC efficiency requirements
Suitable for early adopters and voluntary programs

Tier 3: Advanced performance (30-40% improvement)

Continuous insulation requirements
High-performance glazing mandatory
Mechanical system optimization

Tier 4: High performance (50-60% improvement)

Approaching Passive House-equivalent envelope
Electrification and renewable energy readiness
Heat recovery ventilation mandatory

Tier 5: Net-Zero Energy Ready (60-70% improvement)

Maximum envelope performance
All-electric mechanical systems
Solar PV ready (conduit, structural capacity)
Meets federal 2030 net-zero target

Two Compliance Paths

Prescriptive Path:

Meets specific requirements for each building component (walls, roof, windows, HVAC)
Provides certainty and simplifies compliance checking
Less design flexibility

Performance Path:

Demonstrates energy use through whole-building modeling
Allows trade-offs between envelope and mechanical systems
Requires certified energy modeler
Innovation-friendly approach

Key Technical Requirements by Tier

Envelope Performance (Tier 1 vs Tier 5)

Component	Tier 1 (Baseline)	Tier 5 (NZE Ready)
Wall insulation	RSI 3.5 (R-20)	RSI 7.0 (R-40)+
Roof insulation	RSI 5.5 (R-31)	RSI 10.6 (R-60)+
Floor insulation	RSI 3.5 (R-20)	RSI 7.0 (R-40)
Windows	U-1.4 (double-glazed)	U-0.85 (triple-glazed)
Airtightness	2.5 L/(s·m²) @ 75 Pa	1.0 L/(s·m²) @ 75 Pa

Mechanical Systems (Tier 5 Requirements)

Heating:

Heat pumps with COP ≥ 3.0 at rating conditions
No fossil fuel combustion equipment permitted
Hydronic systems must use condensing heat pumps

Ventilation:

Heat recovery ventilation (HRV) or energy recovery ventilation (ERV) mandatory
Sensible heat recovery effectiveness ≥ 75%
Balanced ventilation (supply = exhaust)

Domestic Hot Water:

Heat pump water heaters (HPWH) with energy factor ≥ 2.0
Or solar thermal pre-heating with ≥ 50% solar fraction
Electric resistance backup allowed

Cooling:

SEER ≥ 16.0 for central systems
Properly sized to avoid overcooling (humidity issues)

Provincial Adoption and Timelines

British Columbia

Current status: BC Building Code 2024 incorporates NECB 2020 with local amendments

Energy Step Code integration:

Step 3 aligns with NECB Tier 1-2
Step 4 aligns with NECB Tier 3-4
Step 5 aligns with NECB Tier 5 (NZE ready)

Provincial target: Net-zero energy ready by 2032 for all new buildings

Zero Carbon Step Code: As of March 2025, EL-1 (Emissions Level 1) mandatory for all new construction—requires measurement and disclosure of operational GHG emissions

Ontario

Current status: 2017 version in effect; 2020 adoption under review

Expected timeline:

Tier 1-2 adoption: 2025-2026
Tier 3-4 voluntary incentive programs: 2026-2028
Tier 5 mandatory: 2030+

Municipal leadership: Toronto considering accelerated adoption for city-owned buildings

Quebec

Current status: Energy code integrated within Quebec Construction Code

Unique requirements:

Stringent airtightness testing mandatory (among first in Canada)
Heat recovery ventilation requirements ahead of national baseline
Renewable energy credits accepted for compliance

Target: All new buildings 25% more efficient than NECB 2020 baseline by 2030

Other Provinces

Alberta: Evaluating NECB 2020; expected adoption 2026 Saskatchewan: Following national timelines (2025-2026 baseline) Atlantic provinces: Various stages of review; PEI leading with 2025 target Territories: Adapted northern climate provisions under review

Compliance Strategies for Builders

Tier 1-2 Compliance (Immediate Focus)

Envelope upgrades:

Increase wall insulation from 2×6 @ 24" o.c. to 2×8 or 2×6 with exterior continuous insulation
Triple-pane windows in climate zones 6-7
Enhanced air barrier systems with blower door testing

Mechanical efficiency:

95%+ AFUE condensing furnaces (if gas heating permitted)
Heat pump equipment meeting cold climate specifications
LED lighting throughout (T8 fluorescent phased out)

Cost impact: +$5,000-$15,000 per home (+2-4% construction cost)

Tier 4-5 Readiness (2030 Preparation)

Electrification readiness:

Size electrical panel for future heat pump loads (200 amp minimum)
Install EV charging circuit rough-in
Design for solar PV (roof orientation, structural capacity, conduit paths)

Advanced envelope:

Continuous exterior insulation eliminating thermal bridging
Airtightness target: 1.0-1.5 ACH50 (blower door verified)
Thermal bridge-free windows and doors

Passive heating/cooling:

Optimize window placement for solar gain
Thermal mass integration
Natural ventilation strategies

Cost impact: +$25,000-$50,000 per home (+8-12% construction cost)

Payback: 15-25 years on energy savings; accelerated by carbon pricing and incentive programs

Benefits of Early Adoption

Regulatory Readiness

Buildings designed to Tier 4-5 today will:

Exceed future mandatory requirements (avoid costly retrofits)
Maintain competitiveness as codes tighten
Qualify for accelerated permitting in progressive municipalities

Market Differentiation

High-performance certified buildings command:

15-20% premium in resale value (Canadian Mortgage Housing Corporation data)
Higher occupancy rates (commercial tenants prioritize ESG performance)
Lower operating costs attracting budget-conscious owners

Access to Incentives

Current programs supporting NECB Tier 4-5 construction:

Federal:

Canada Green Building Strategy funding
Low-interest financing through CMHC green mortgages

Provincial:

BC: Energy Step Code incentives ($2,500-$5,000 per unit)
Ontario: Greener Homes Initiative (residential)
Quebec: Rénovert program extensions for new construction

Municipal:

Expedited permitting (Vancouver, Ottawa)
Development charge rebates
Density bonus provisions (Toronto, Montreal)

Technical Resources and Support

Energy Modeling Tools

Free/Low-cost:

HOT2000: NRCan residential modeling software
RETScreen: Feasibility analysis for all building types
EnergyPlus: Advanced whole-building simulation

Commercial:

TRACE 3D Plus: ASHRAE 90.1 and NECB compliance modeling
IES VE: Integrated environmental simulation
DesignBuilder: EnergyPlus interface for architects

Professional Certifications

Energy advisors:

NRCan Certified Energy Advisor (residential)
Certified Energy Manager (CEM) for commercial

Building performance:

Passive House Designer/Consultant
LEED AP with specialty credentials
Certified Sustainable Building Advisor (CSBA)

Reference Standards

ASHRAE 90.1: Commercial building energy standard (US-based, influential in Canada)
Passive House Institute: Cold climate certification standards
Canada Green Building Council: Zero Carbon Building standards

Challenges and Solutions

Challenge 1: Higher Construction Costs

Solution:

Value engineering: Optimize building form (minimize surface area/volume ratio)
Economies of scale: Design reusable high-performance assemblies
Integrated design: Coordinate envelope and mechanical early (avoid expensive changes)

Challenge 2: Skilled Labor Shortage

Solution:

Workforce training: Partner with trade schools on high-performance construction
Prefabrication: Factory-built wall panels with integrated insulation and air barriers
Quality assurance: Third-party verification catching errors early

Challenge 3: Cold Climate Performance Uncertainty

Solution:

Proven assemblies: Reference Northern COMET program designs
Hygrothermal analysis: WUFI modeling preventing moisture problems
Post-occupancy verification: Measure actual energy use, adjust future designs

Looking Ahead: 2030 and Beyond

Net-Zero Carbon Integration

Future code editions will expand beyond energy efficiency to address:

Embodied carbon:

Whole-life carbon assessments (construction + operations)
Material carbon intensity limits
Reuse and recycled content requirements

On-site renewables:

Mandatory solar PV or equivalent renewable energy
Energy storage integration
Grid-interactive efficient buildings

Electrification mandates:

Phased elimination of fossil fuel systems
All-electric requirements for new construction

Alignment with Climate Goals

Canada's commitment to 40-45% emissions reduction by 2030 requires:

100% of new buildings meeting Tier 4-5 by 2030
Aggressive existing building retrofit programs
Coordinated federal-provincial-municipal action

NECB 2020 provides the technical foundation. Implementation speed depends on political will, incentive program design, and industry capacity building.

Conclusion

The National Energy Code for Buildings 2020 represents Canada's most significant building performance upgrade in decades. The tiered framework provides a practical roadmap from current practice to net-zero energy ready construction, allowing jurisdictions to adopt requirements matching their climate goals and industry readiness.

Builders, developers, and designers should:

Familiarize themselves with Tier 1-2 requirements now (mandatory adoption imminent)
Explore Tier 4-5 designs to understand future expectations
Engage energy modelers early in project planning
Access available training and incentive programs before demand peaks
Monitor provincial adoption timelines and requirements

The transition to high-performance buildings is no longer optional—it's the new baseline for Canadian construction. Those who embrace NECB 2020's tiered framework today will be best positioned to thrive in Canada's decarbonized building sector of tomorrow.

For detailed technical requirements and compliance guidance, consult the full NECB 2020 available through the National Research Council at nrc-publications.canada.ca, and check your provincial/territorial authority for local adoption status and amendments.