1) this could only be implemented for new construction buildings as alterations sometimes do not touch the envelope and/or HVAC systems. As time goes on, more projects are renovations rather than new construction meaning only a fraction of buildings would apply.
2) especially on the residential side of things at the moment, the industry is somewhat constrained by the limited number of small capacity heating and cooling systems. I.e. in a well designed apartment, are they going to have to resort to through only wall A/Cs or variable capacity systems?
3) significant support to non-energy savvy designers and builders would have to be implemented. What does a building look like that meets these standards? What has to be done to achieve this? And in so doing, you basically end up with the energy code.
4) through this method, a failure of energy efficiency results in a failure of human comfort after the Certificate of Occupancy has already been granted. The primary fix to a now existing building is to add greater capacity system so people are comfortable.

I am afraid that in both
I am afraid that in both counts we are against the grain. HVAC people have no clue what efficiency, and sizing is about, and they earn more with larger, so no incentive.
As to home sizes, builders and their subs go for the BIG, clients like BIg as it is about their status..
Until we have energy tax (allocated by how far from passive one goes) on houses and cars (anything less than 100 miles per gallon or eq) , nothing will change.

1) this could only be implemented for new construction buildings as alterations sometimes do not touch the envelope and/or HVAC systems. As time goes on, more projects are renovations rather than new construction meaning only a fraction of buildings would apply.
2) especially on the residential side of things at the moment, the industry is somewhat constrained by the limited number of small capacity heating and cooling systems. I.e. in a well designed apartment, are they going to have to resort to through only wall A/Cs or variable capacity systems?
3) significant support to non-energy savvy designers and builders would have to be implemented. What does a building look like that meets these standards? What has to be done to achieve this? And in so doing, you basically end up with the energy code.
4) through this method, a failure of energy efficiency results in a failure of human comfort after the Certificate of Occupancy has already been granted. The primary fix to a now existing building is to add greater capacity system so people are comfortable.

On the other hand, GC's might find it easier to pad themselves by going beyond the minimum specs indicated by the model (a good thing), but they would have no incentive to further downsize the equipment. In other words, there would be a perverse incentive ratchet up the envelope specs a bit and then install the largest hvac allowed by code.

Hmm…

On the other hand, GC's might find it easier to pad themselves by going beyond the minimum specs indicated by the model (a good thing), but they would have no incentive to further downsize the equipment. In other words, there would be a perverse incentive ratchet up the envelope specs a bit and then install the largest hvac allowed by code.

Hmm…