Homebuilding is up. Why is that good for construction?

Per the Calculated Risk blog (a good one is you're a finance junkie), there's good news coming from homebuilders.  For the complete story, click here.  This excerpt is the best part:

"As at September 30, D.R. Horton sales order backlog of homes under contract jumped 49 percent 20 7,240 and the value of the backlog increased 61 percent to $1.7 billion."

Most of my readers are likely not going to work in the single-family housing construction market, so why is this important?  Well, the key word is backlog.  There has been good news coming out of the homebuilding market recently, but my hunch was that homebuilders were selling the houses that they overbuilt during the housing bubble and were trying to reduce a glut of inventory.  But this data suggests otherwise and that much of the sales are coming from new houses.  So again, why is this important?  New houses = new infrastructure and all that comes with it (new schools, new retail centers, etc.), which means more construction in the areas that will likely interest my readers.  Hopefully this trend continues.