One of the great banking laws in this country is the mandatory APR for loans. That’s a calculation that allows consumers to easily compare loans that have different fees, terms, and rates, making it all apples to apples.

We need the same type of law for home buying. The formula should show the total cost of the home including energy use, water, and maintenance, under some standard set of assumptions.

That sort of number would be a big help to consumers. But more important, it would give home builders an incentive to exceed minimum energy efficiency standards, and make maintenance cheap. At the moment, energy efficiency is somewhat invisible to the buyer. Buyers aren’t willing to pay more for a vague concept. But they might pay more for a home that costs them less in the long run, if they trusted the calculation.

That's my world-saving idea for today. If that doesn't save the world, I will come up with something else tomorrow.