Get the Best of Everything.
Sometimes taking it the efficiency extreme does not make complete sense for a project. But does that mean to abandon the idea altogether? Far from it. Park Slope Passive Measures took the high performance methodology as far as it made sense and still achieved greater than 50% energy reduction while not breaking the budget. And even better, from all that has been learned since its completion, you can now go all the way to PH within the same budget nut. Well done.
(Add in solar PV and a home energy control system, and you have a net-zero building that can sail into the future.)
Architect: Sarah Jefferys Design http://www.sjdny.com
Engineer: BauKraft Engineering http://www.baukraft.com
Passive House Consulting: sgBUILD