Dear fellow Canadian energy modellers.

We are involved with the energy modeling of a residential glass tower which aims at a LEED Canada-NC certification.

The building envelope is mostly curtain walls with limited amounts of opaque components (spandrel panels among them). When running the model, EE4 gives us an error message saying the building doesn't meet the mandatory requirement 8.2.1.4.(2), which means that the proposed building opaque envelope components (walls and roofs) have an overall U-value higher than 167% of the reference building overall U-value.

Normally, not meeting a mandatory requirement means the building cannot be certified for LEED Canada.

We are trying to find if the CaGBC has generally been lenient about this requirement or not..? I can't find a CIR, or other source / example saying so.

Of course, among the ways around would be to design and model the building against ASHRAE 90.1... but that would means checking against a whole new set of mandatory prescriptions, and completely reworking the energy model. Which we are trying to avoid.

Another way is to remove all offending spandrel panels and replacing them with regular glass component. Not sure how the architect will take this.

Any input / help on this is appreciated.

Fr?d?ric Genest