For purpose-built rental developers, CMHC’s MLI Select program has become one of the most important factors in project financing. Energy efficiency is one of the three ways to earn points, alongside affordability and accessibility. More points can mean lower insurance premiums and longer amortizations.
CMHC has set September 30, 2026 as the last day it accepts energy attestations based on the 2017 NECB or 2015 NBC for new construction. After that, projects are measured against the 2020 editions of those codes.
Why the baseline change matters
MLI Select energy points for new construction are awarded as a percentage improvement over a reference building. At the time of writing, CMHC’s published tiers are:
- 20 points: at least 25% better than NECB, or 20% better than NBC
- 35 points: at least 50% better than NECB, or 40% better than NBC
- 50 points: at least 60% better than NECB, or 70% better than NBC
The 2020 codes already require more efficient buildings than the 2015/2017 editions. The reference building is tougher to beat, so the same design will usually score a smaller improvement percentage than it would have under the old baseline. Projects that were comfortably in a tier on paper may now fall short.
Where mechanical and electrical design moves the needle
Envelope improvements matter, but in multi-unit residential buildings the biggest percentage gains usually come from building services:
- Heating and cooling source. Moving from gas-fired make-up air and boilers to air-source or water-source heat pumps is often the single largest lever.
- Ventilation heat recovery. High-efficiency ERVs/HRVs serving suites, instead of unrecovered corridor pressurization, cut heating energy substantially.
- Domestic hot water. Heat pump water heating, drain water heat recovery and low-flow fixtures reduce a load that is often underestimated.
- Lighting and controls. LED lighting with occupancy and daylight controls in common areas and parking, plus demand-controlled garage ventilation.
Keep the energy model and the drawings aligned
An energy model is only as good as its match with what gets built. The most common problem we see is the model assuming equipment efficiencies, ventilation rates or controls that never make it into the mechanical drawings, or that get value-engineered out during construction. Bring your MEP engineer and energy modeller together at schematic design, agree on the systems that deliver the target, and track them through tender and shop drawings.
What to do now
- If your project is still in design, confirm which code edition your attestation will be based on.
- Re-check your target tier against the 2020 baseline before finalizing systems.
- Price two or three mechanical strategies side by side, looking at capital cost, operating cost and points, before the architect locks in shafts and mechanical rooms.
Miriton’s team includes a Certified Energy Manager and a LEED AP. We do the energy modelling and MLI Select energy attestation in-house, and design the mechanical and electrical systems around the target your financing needs, so the model and the drawings match. Request a fee proposal and tell us your target tier.
Program details change. Always confirm current MLI Select criteria directly with CMHC or your mortgage broker. This article is general information, not financial advice.