'Growing pains' for home builders: Lack of lots, rising cost of materials and labor

The housing market's comeback has hit a speed bump -- an index of home builders' confidence slipped again in March.

The index, which is compiled by the National Association of Home Builders and Wells Fargo, is on a three-month slide after eight months of gains. It's based on home builders' perception of current sales for new single-family homes and their expectations for future sales.

Demand isn't the problem; supply is. There are "frustrating bottlenecks in the supply chain for developed lots,…