I live in a hundred year-old house where most everything is original: the windows (drafty), the walls (uninsulated), the furnace (burns oil). I need only look at my heating bill every month to deduce what the Commission for Environmental Cooperation has determined through a two-year study–homes and office buildings in North America account for over one-third of the continent’s greenhouse gas emissions. They are terribly inefficient.

The solution is, of course, upgrading the older structures with insulation and tight-fitting windows and using better building practices with more efficient materials in new construction. Builders in North America have been slow to adopt the more expensive materials for two reasons. The first is the cost of energy-saving mechanicals. The investment for builders doesn’t pay off as well as the eventual savings for the owners.

The second is the market share for green materials. It currently accounts for a tiny percentage of sales. As long as that number stays low, traditional materials will be significantly cheaper. It’s not until that gap is narrowed that the cost differential will come down.

The market in North America has been slow to change, which is why green building accounts for only 2% of all new commercial buildings and 0.3% of new homes; Europe is already substantially ahead in this realm because of government-enforced targets. We’ll need to see more intervention in North America if we’re ever to catch up.