So you would have to model each home independently. I can tell you that on an Energy Star home, which costs about $4,000 or $5,000 more than the average house, the savings are about 30% compared with a conventional home built under the building code. So it's in the area of probably $600 or $700 or $800 a year on an average home. That's in the new home market.
We do have rules of thumb for windows, furnaces, and those kinds of things. I think part of the job of the auditors is to ensure that the dollars are being placed where the greatest level of energy efficiency is being realized for the dollars spent. I think that's an important component.