Trial / Demo
On 29 July 2026, we hosted a webinar on navigating NECB compliance with IESVE. Attendees asked questions on code paths, EUI targets, geometry, data exchange, loads calculations, HVAC system modeling, reporting, and general use of the IESVE Navigator.
We've compiled the most common questions below as a reference for webinar attendees and anyone looking to streamline their NECB compliance workflow in IESVE.
Not in the same sense. NECB 2025 Part 8 provides two target-setting methods. Under the fixed EUI method in Article 8.4.4., the proposed model is compared with a prescribed EUI target, or an area-weighted target for an eligible mixed-use project. A project-specific reference building is not generated. Under Article 8.4.5., the proposed model is compared with a modeled reference building whose geometry and use largely match the proposed building, while code rules establish reference envelope, lighting and system characteristics. Use the target method permitted for the project and accepted by the AHJ.
The fixed-target method is available only when at least 90% of the summed gross interior floor area with known functions is associated with the listed archetypes, and where the project meets the heating-degree-day applicability criterion. The code does not use “commercial” as a catch-all archetype. An office may qualify as office, but retail, laboratory, healthcare and most industrial functions are not independently listed.
NECB 2025 Fixed EUI Targets
| Eligible archetype | Target, kWh/(m2.year) |
| School, kindergarden to Grade 12 | 125 |
| Multi-unit residential, 6 storeys or fewer | 225 |
| Multi-unit residential, more than 6 storeys | 175 |
| Office | 175 |
Applies where the fixed-target eligibility requirements are met, including the heating-degree-day limit. Source: NECB 2025, Table 8.4.4.1
If the project is not eligible for the fixed EUI method, use the modeled reference-building method or another permitted prescriptive or trade-off route. Where a jurisdiction requires an above-minimum energy tier, the selected route must also demonstrate the required improvement.
NECB applicability is determined by the code scope and its local adoption, not simply by an “industrial” label. NECB 2025 generally addresses new buildings, additions and alterations within its scope, while farm buildings are excluded and process equipment loads are generally outside the code scope. Because most industrial archetypes are not listed for the fixed EUI method, an industrial project seeking performance compliance will normally use the modeled reference-building method. Prescriptive or trade-off options may also be available. Confirm the occupancy, process boundaries and adopted route with the AHJ.
For an eligible mixed-use project, NECB 2025 calculates an area-weighted building energy target from the listed archetypes. At least 90% of the known gross interior floor area must be associated with those archetypes. Unlisted functions can therefore form only a limited share of the project under this method, and the code distributes those unlisted areas proportionally when setting the target.
Parking is not a listed archetype. Do not derive the compliance denominator from total ModelIT floor area without checking the code definition and the applicable reporting guideline. Unconditioned parkade area is commonly excluded from conditioned-archetype area, while parkade energy may still require treatment in the model or report. Document the included area and confirm it with the AHJ, especially where local Step Code or municipal rules also apply.
The table values do not have separate climate-zone multipliers. They apply only at locations with fewer than 9,000 heating degree-days at 18 °C. Within that range, the target is fixed by archetype, but the proposed building's simulated EUI will still respond to weather and climate. If the modeled reference-building method is used, climate-zone envelope and system requirements directly affect the reference model.
Yes, when the adopting jurisdiction requires both. Part 10 establishes energy performance tiers, while Part 11 establishes operational greenhouse-gas performance levels. They are separate checks. Using the fixed EUI method does not waive greenhouse-gas compliance, and meeting a greenhouse-gas target does not replace the required energy improvement. The jurisdiction selects the tier and greenhouse-gas level that apply to a permit.
NECB 2025 directs users to the value specified by the provincial or territorial AHJ, an approved utility value where permitted, or the code table when neither is provided. IESVE's NECB 2020 workflow supplies default factors but explicitly instructs the user to update them for the current province and energy supplier. Project values are editable. For repeat work, use a controlled project template or documented input set, but validate the factor for every project and record its source, year, units and fuel basis.
NECB 2025 Appendix C includes historical and future climate design data. Its explanatory note states that the historical July 2.5% temperatures are intended for mechanical cooling design. Using the future 50-year values directly for equipment sizing can oversize cooling equipment and reduce humidity control and part-load efficiency. Use future conditions as a resilience or sensitivity scenario unless the adopted code, owner requirement or AHJ directs otherwise. Keep design-day sizing conditions separate from annual simulation weather and document both.
Apply the alteration provisions of the edition adopted for the project. Under NECB 2025 Part 13, new HVAC systems and existing HVAC systems subject to alteration are in scope, while repair and maintenance are excepted. Altered or replacement components generally comply with Part 5. Unaltered portions are brought into scope only when specified triggers are exceeded, including an added thermal load greater than 60% of the existing peak design load or added or replacement duct or piping length greater than 60% of the existing distribution length.
A local duct modification for a new office layout does not automatically mean the entire central plant must be replaced, but the alteration scope and trigger calculations must be documented. Envelope, lighting and service-water-heating alterations have their own provisions. Earlier NECB editions and local amendments differ, so obtain an AHJ determination before finalizing the compliance approach.
Development of NECB 2025 has begun and will be available early next year.
The templates will reflect the 2025 version. While the systems are largely the same, performance characteristics will have changed and been included in the future IES release.
No. The Navigator brings the existing VE modules, including Apache and ApacheHVAC, into a guided compliance workflow. It manages project states, required inputs, reference-model generation, checks and reports; it does not use a separate simulation engine.
Yes. The user may simulate the reference building with different hvac systems if they wish.
Create and organize the thermal zones in ModelIT before assigning them to ApacheHVAC. Use the “HVAC Zones and Zone Groups” grouping scheme, connect spaces that genuinely share a thermostat or terminal control where appropriate, and organize zones by the systems that serve them. ApacheHVAC then uses this zone structure for system assignment, sizing and simulation; it is not the primary place to define room geometry or thermal-zone boundaries.
Tools > Colour Preferences > Background Colour
Yes. Build the stepped levels and split the geometry where needed so that each surface portion can be classified correctly as above-ground, ground-contact or adjacent. Review adjacencies and run the Model Consistency check before simulation. A topographical shade can represent solar obstruction from terrain, but it does not by itself define ground heat transfer. For compliance, verify that the generated reference model retains the geometry and exposure required by the selected code method.
IESVE can create a project from IFC, gbXML or veXML.
Current productivity tools include Tabular Space Data and Tabular Building Template Manager for bulk editing and filtering, room and project templates, grouping schemes, HVAC libraries, keyboard shortcuts, reusable profiles, and batch simulation of saved model variants. These features reduce repeated dialog entry and make quality checks more systematic.
In relation to Interface / AI updates planned…..watch this space!
No. ASHRAE Loads can calculate room and zone heating and cooling loads from geometry, constructions, internal gains, schedules, ventilation, setpoints and design weather without a detailed ApacheHVAC network. A detailed system is required when the objective is system-level coincident loads, system autosizing, control interaction or annual HVAC energy performance.
Yes. Use peak sensible and latent room or zone loads as sizing inputs and design checks, then account for ventilation, supply-air conditions, humidity control, heat recovery, fan heat, pickup, diversity and system configuration. Use the room or zone load workflow and ApacheHVAC system sizing.
Yes. A prototype system can be modified, or a custom ApacheHVAC network can be created, assigned to rooms or zones, given controls and setpoints, and then taken through room or zone sizing followed by system-level sizing. The system does not have to remain unchanged from the library. A custom network must have valid topology, parameter links and sizing data so that the calculations can update airflows, capacities and related component parameters correctly.
IESVE includes generic prototype systems, components and user-managed libraries, together with detailed performance inputs and curves. There are libraries of some manufacturers equipment such as Mitsubishi, Daikin or other manufacturer models, but these are not continuously maintained.
Yes. For NECB 2017 and 2020, IESVE provides a simple coefficient approach and a detailed Psi and Chi approach. In the proposed building, users can enter construction-level coefficients or select and customize Psi values; random thermal bridges can be drawn and assigned Chi values. In the reference building, the thermal-bridge inputs are locked because the applicable NECB reference transmittance tables already account for thermal bridging. Confirm the dimensional convention used for custom values.
Yes, IESVE can model the building and produce the energy, thermal-demand and greenhouse-gas metrics needed for BC Energy Step Code work.
The commonly used VistaPro TEDI custom variable is derived from modeled heating demand and the selected floor-area basis. It is an unadjusted result.
IESVE also supports HVAC design, energy modelling, decarbonization studies, daylighting analysis, and operational performance optimization, and automates much of the baseline model creation and compliance reporting covered above.
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