One Energy Model, Two Compliance Pathways: NECB 2020 and CMHC MLI Select
Energy Modeling
The proposed building energy model, developed in IES-VE from architectural, electrical, and mechanical design documents.
- 6-Storey Multi-Family Residential
- Calgary, Alberta
- Code Compliance + Financing Eligibility
Case Study Summary
Service | Energy Modeling — NECB 2020 code compliance + CMHC MLI Select financing eligibility |
Building Type | 6-storey multi-family residential, 89 dwelling units |
Location | Calgary, Alberta, Canada (Climate Zone 7A) |
Floor Area | ≈6,917 m² (≈74,400 ft²) |
Software | IES-VE, ASHRAE 140-compliant |
Compliance Pathways | NECB 2020 Performance Path (Part 8) for building permit; NECB 2017 reference baseline for CMHC MLI Select Energy Efficiency Level 1 |
Result | 8.6% better than NECB 2020 reference (permit-compliant); 25.7% energy / 25% GHG reduction vs. NECB 2017 reference (MLI Select Level 1 achieved) |
Client | Confidential (design engineering firm) |
The Challenge
A 6-storey, 89-unit residential building needed to clear code compliance for its building permit — but the developer was also pursuing CMHC’s MLI Select program, which offers preferential financing for rental housing that hits specific energy and GHG reduction targets. The complication: MLI Select’s published Energy Efficiency Level 1 requirement is measured against the NECB 2017 reference building, not the current NECB 2020 code the project actually has to comply with for permit. The same design had to be evaluated against two different reference baselines, for two different audiences — the building department and CMHC — each with its own methodology and its own bar to clear.
Our Approach
We built the proposed design as a single detailed IES-VE model — covering envelope, fenestration, the central boiler heating plant, suite-level DX cooling with heat-recovery ventilation, corridor pressurization, and parkade heating and ventilation — then ran it against two separate reference buildings: an NECB 2020 reference model built for the permit submission, and a separate NECB 2017 reference model built specifically for the MLI Select application, each following its own code year’s prescribed methodology.
A subset of the HVAC system configurations modeled in IES-VE — suite DX cooling with hydronic baseboard heating, corridor make-up air units, parkade hydronic unit heaters, and ancillary-space forced-flow heaters, each represented on its own terms.
Envelope U-values weren’t taken from nominal, clear-field insulation values — they were corrected for thermal bridging at every stipulated component intersection using the Building Envelope Thermal Bridging Guide methodology, across 10 distinct interface types (corners, roof and parkade intersections, window and floor-joist junctions, and more). The derating was substantial: the wall assembly’s clear-field rating of roughly R-26 dropped to an effective R-15.5 once thermal bridging was included — a 41% reduction — and the roof went from a clear-field R-47 to an effective R-31.5. A compliance model built on clear-field values alone would have reported an envelope performing up to 41% better than the one actually being built.
Unmet heating and cooling hours were also verified in both models — confirming the HVAC system as modeled could actually maintain setpoints throughout the year, not just produce a favorable energy number on paper.
Results
8.6%
Better than the NECB 2020 reference building — permit compliance
25.7%
Energy reduction vs. the NECB 2017 reference — MLI Select pathway
25%
GHG reduction vs. the NECB 2017 reference — right at the MLI Select threshold
Two compliance results came out of the same underlying design: the proposed building beat the NECB 2020 reference by 8.6% for its building permit, and separately beat the NECB 2017 reference by 25.7% on energy and 25% on GHG emissions — clearing CMHC’s MLI Select Energy Efficiency Level 1 threshold (25% required on both metrics), with the GHG result landing right at the line rather than comfortably above it. That’s a useful reminder that MLI Select eligibility isn’t automatic just because a design comfortably clears code — it has to be checked against its own, different bar.
Proposed vs. NECB 2020 reference building energy performance — the permit-compliance comparison. The MLI Select comparison against the NECB 2017 reference was run separately, per CMHC’s requirement.
Why It Matters for Your Project
For a developer, code compliance is necessary but doesn’t unlock financing on its own — CMHC’s MLI Select program rewards additional performance with meaningfully better loan terms, but only if the energy model can prove the design clears its specific, differently-referenced bar. Running both compliance paths from one coordinated model meant the project satisfied its building permit requirement and the financing program’s requirement without two disconnected analyses — and gave the design team one clear, defensible number for each audience that needed one.