The New York Times explains passive houses and also describes several obstacles to building more of them:

Proponents of passive building argue that the additional cost (which is estimated at 5 to 20 percent) will come down once construction reaches critical mass and more American manufacturers are on board. And there are a few signs that day may be coming. More than 1,000 architects, builders and consultants have received passive-house training in this country; at least 60 houses or multifamily projects are in the works; and Marvin Windows, a mainstream manufacturer based in Minnesota, recently began making windows that meet passive certification standards…

“What I’m worried about,” he said, “is that the current halo around the passive-house standard will result in its being incorporated into the building code. That would be unfortunate because they are unnecessarily expensive houses, from $300,000 to $500,000 on average, that cost more than will ever be justified by lifetime energy savings or carbon reductions.”

Mr. Holladay favors a more flexible formula called the Pretty Good House, which promotes modest improvements in insulation coupled with renewable energy from solar panels — an approach, he said, that achieves similar energy savings without the additional expense.

To make things more complicated, no two passive houses are likely to be built to exactly the same specifications. Thousands of variables, including the architectural design, the size of the house, how many people will live there, and longitude and latitude, are taken into consideration by the sophisticated software created by Dr. Feist and his Passivhaus Institute in Darmstadt, Germany…

Figuring out how to make the model work in the hot, humid Southeast is a bigger challenge, something the Europeans have not had to deal with. With this in mind, Ms. Klingenberg’s organization is working to develop American standards, taking into account variations in energy use and leakage rates from one climate zone to another; they are expected to be released this fall.

In other words, these are complicated homes and this gets added to the cost. Like other technological innovations, manufacturing and building at a larger scale could soon help make them more accessible and understandable. Additionally, the context matters as well. If standards like building codes and environmental expectations about new houses change plus consumers display more interest in unique, green homes, there may be more and more passive homes in the coming years.