
Thats a good question.
I mean if you can still make a better profit on conventional construction, why bother? At the same time if energy costs get higher, the owner benefits from the energy efficiencies. However, they must be willing to pay extra so developer can price in the cost these benefits. If the future owner is saving money on energy costs, isn't the higher purchase cost helping affordability in the long-run?

Homeowers versus condos is a different return value. It could take many years to recieve the benefit of any savings for a homeowner. Whereas, a condo with higher energy reuqirements could benefit sooner.
The bigger return will be when energy prices go up.
Another issue is mandating LEED. If it makes business sense to do LEED why mandate it?

The provincial government and the City of Vancouver have some policies for LEED Gold with new buildings. If we are going to be wasting money on pet project might as well build LEED Gold buildings

But seriously, requirements for above standard projects is a shift towards best practice instead of minimum requirement. (Would have been nice if they had checked how many LEED APs there were -backlog should be finally cleared by March 2011)
LEED offers long-term savings for owners and does not have a large impact on affordability. Building a city between a mountain range, an international border and the ocean affects affordability.

Using our exisiting residential areas more effectively like the Cambie Corridor through the various implementations of density and housing options, is better way to address affordability. (I totally brought it back to the thread there!)