Building codes now offer a performance path: demonstrate through modelling that a design beats a reference building, rather than meeting every prescriptive requirement. It usually costs less to build and it needs a model somebody will stand behind.
An energy model is a simulation of how a building will perform — its envelope, mechanical systems, lighting, occupancy and the climate it sits in — used to demonstrate something to somebody. Usually a code official, a lender, or a program administrator.
What the model must prove differs completely depending on who is asking, and building one model and hoping it satisfies everybody is how submissions get rejected.
| Purpose | Applies to | Demonstrates |
|---|---|---|
| Ontario Building Code SB-12 | Housing under Part 9 | Performance-path compliance against a reference house |
| Ontario Building Code SB-10 | Larger buildings | Energy efficiency compliance referencing the NECB |
| NECB | Commercial and institutional new construction | Whole-building performance against the code reference |
| CMHC MLI Select | Multi-unit residential | Improvement over baseline for energy efficiency points |
| Calibrated model | Existing buildings, ASHRAE Level 3 | Measure savings with interactive effects, tuned to metered data |
| Net-zero pathway | Any building facing carbon limits | What it would take, in what order, at what cost |
Energy modelling is not one piece of software. Each submission has a tool that its reviewers expect to see, and a model built in the wrong engine is rejected on process before anyone reads the engineering. We keep a working capability across the platforms Canadian reviewers actually accept.
| Tool | What we use it for |
|---|---|
| CAN-QUEST | The Canadian NECB compliance route. Natural Resources Canada's adaptation of the DOE-2 engine, built specifically for performance-path demonstrations against the National Energy Code for Buildings, and the reference point for Ontario's SB-10. |
| eQUEST / DOE-2 | General whole-building simulation and ASHRAE 90.1 Appendix G baseline comparisons. Fast to build, well understood by reviewers, and the right tool when the question is comparative rather than absolute. |
| EnergyPlus & OpenStudio | Where DOE-2 cannot represent the systems honestly — detailed HVAC control sequences, thermal storage, heat recovery networks, hourly emissions accounting and net-zero pathway work. |
| RETScreen Expert | Natural Resources Canada's own feasibility and performance platform. We use it for clean-energy and fuel-switching business cases, portfolio-level screening, and ongoing performance tracking after measures are installed. |
| Load and sizing tools | Heating and cooling load calculations where the deliverable feeds mechanical design and equipment selection rather than a compliance submission. |
| IPMVP measurement & verification | Options A to D, applied after construction to prove what the model predicted. Required by most custom incentive programs before the final payment is released. |
Where a program administrator, a code official or a tender names a specific platform, we work in that platform. Where nobody has named one, we choose on the engineering — the simplest engine that can represent the building honestly, because an unnecessarily complex model costs more, takes longer and is harder for a reviewer to accept.
Two things get modelling submissions rejected more than any engineering error: the wrong tool, and the wrong baseline. Both are decided in the first hour of the job and both are expensive to undo.
If a program or a reviewer has a stated preference, tell us at the start. If you do not know, we will find out before any modelling begins — that call takes minutes and has saved projects weeks.
Most codes offer both routes. The prescriptive path gives you a package of requirements — insulation values, window performance, equipment efficiencies — and if you meet them all, you comply. It needs no modelling and it is simple.
The performance path lets you trade off. A design with more glazing than a package allows can compensate with better mechanical systems, and a model demonstrates the overall result meets or beats the reference.
The performance path usually wins when the design does not fit the prescriptive boxes: unusual glazing ratios, heat pumps, heat recovery, or an architectural feature the packages treat harshly.
It also wins when the prescriptive package would force an expensive upgrade to one element that a cheaper improvement elsewhere could offset. The modelling fee is frequently less than the construction cost it avoids — but that only works if the modeller is involved while the design can still change.
Bring a modeller in at schematic design and the model informs the design — orientation, envelope, glazing ratio and mechanical selection get chosen partly on performance, at no construction cost premium.
Bring one in at permit and the model documents whatever was already decided. If it falls short, the only remaining options are expensive: better glazing, more insulation into a finished wall assembly, or upgraded equipment.
The fee is similar either way. The construction cost is not.
For existing buildings, a model becomes far more useful once it is calibrated — tuned until it reproduces the building's actual metered consumption within an accepted tolerance.
Calibration work is done in eQUEST or EnergyPlus depending on the systems involved, against twelve to thirty-six months of metered data. A calibrated model is what makes Level 3 audits investment grade. It handles interactive effects properly: an LED retrofit reduces cooling load and increases heating load, envelope work changes the value of a mechanical upgrade, and measures assessed in isolation always add up to more than they deliver. A calibrated model shows the bundle as it will actually behave.
Where a permit submission, a financing attestation or a tender requires a Professional Engineer's seal, we provide it. Our team includes P.Eng and mechanical engineering capability, and CMHC's MLI Select attestation requirement — P.Eng, Architect, Certified Engineering Technologist or CEM — is satisfied in-house.
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A compliance deadline, an incentive application, a financing requirement, or a capital plan. Tell us which, and we will tell you what you need and what it will cost — as a fixed fee, before any work starts.
If you do not need an audit, we will say so.