If you’re really itching to hear someone say “duh,” just tell them with a straight face that houses are too expensive in Los Angeles.

Lots of companies put housing affordability near the top of their concerns about doing business here. Sure, middle-class workers can find acceptable family homes that are kind of affordable, but those houses may be so far inland they face commute times that could be measured by a calendar.

Everybody knows it’s a problem. The big question: What to do?

Mayor Antonio Villaraigosa last week announced a huge plan – as in $5 billion – to create more affordable housing in the city.

Now, I’m not going to quibble about the particulars of how the plan will work. Let’s leave that for another time. And I’m certainly not going to question his desire or motive. The impulse to do something to help this dire situation is understandable, commendable even.

The part I don’t understand is this: Isn’t this the same city government that’s actively tried to make homes more expensive?

After all, it is notoriously difficult and expensive to build homes in Los Angeles. There’s all kinds of restrictions, fees, height limits on condo buildings and the like. Of course, not all of these rules and expenses are bad or undesirable, but the totality of them makes homebuilding difficult and expensive. The result: Not enough homes get built to keep pace with demand.

As reported in the Los Angeles Business Journal earlier this year, L.A.’s Department of Housing said the city needed 8,600 net new housing units a year just to keep up with demand. But from 1999 through 2003, the city added just 4,800 units a year. That contributed to a supply-and-demand imbalance, and that helped turbocharge home prices here. After all, whenever any commodity in demand is seen as dear, the price goes up.

One of the policies that has contributed to the problem is inclusionary zoning, or the requirement that house or condo builders make a certain percentage of their new units affordable. That’s one of those feel-good policies that makes voters think politicians are doing something good. And while inclusionary zoning helps the lucky few who score one of the affordable units, unfortunately, it makes matters worse for the rest of us.

It only stands to reason that builders may boost the prices of their regular, market-priced units to make up for the haircut they take on the affordable units. A study by a couple of researchers at the Independent Institute concluded something a little different. It found that California cities that adopted inclusionary zoning saw 10 percent fewer housing units built than those cities that didn’t. In either case, whether builders are boosting prices to make up for the loss or just constructing fewer units, it means higher overall housing prices. That’s thanks to a city policy.

Another thing that’s odd about Villaraigosa’s plan is the timing. It was announced last week, right in the midst of the market meltdown. Let’s put aside the question of whether the $5 billion plan can get funding. Instead, consider the fact that house prices here are falling by the hour. Affordability may be less of a concern soon.

If the city reviewed some of its policies with an eye toward cutting the ones that boost house prices – and just waited awhile for the market to settle back – we just may find that lots more folks can buy a house here for a reasonable price. And it wouldn’t take a $5 billion program.