Drew Industries Inc., parent of supplier firms Kinro and Lippert, reports its RV industry-related sales revenue increased 31% during the first three months of this year to $24.1 million.

However, the company’s earnings declined 30% and its total revenues were down 13% during the first quarter because of the sluggish manufactured housing market.

Drew earned $2.8 million on total sales of $74.7 million during the three months ended March 31.

Drew is so upbeat about its RV industry-related business that it plans to build five new factories this year to satisfy the demand.

Kinro produces windows and doors for RVs and Lippert assembles chassis for towables.

Drew shares were down 5/16 in American Stock Exchange trading today to close at 6 7/8.