Scientists tell us the universe is expanding, but that can’t account for how much bigger Americans’ houses have gotten in the last 40 years. Our houses have more than doubled in size in the past generation, and that doesn’t even calculate the fact that most teenagers now have two houses to call home — one for dad and his new wife and another for mom and her new husband. Why have houses exploded in size? Because lenders forced down the fees charged by appraisers until it was no longer feasible (or even expected) for appraisers to anything more than a drive-by when calculating the value of a home. Instead, they have relied on “comps” that focus almost entirely on square footage — quantity, not quality — of comparable houses in the area and what they have recently sold for. Building quality and attention to detail are no way to get ahead in that sort of economy, until it stops working. Like now.