Lowe's ( LOW) reported a 21% spike in first quarter earnings and topped analyst estimates by a penny thanks in part to the solid housing market. The company earned $421 million, or 53 cents a share, in the quarter ended May 2, compared with $346 million, or 44 cents a share. Analysts were expecting 52 cents a share. "A strong housing market and improving consumer confidence continue to support the American conviction to invest in the home despite the effect of adverse weather and uncertain world events," said Robert L. Tillman, Lowe's chief executive. Lowe's opened 21 new stores during the quarter and the company said it now has 875 stores total. Total sales rose 11% to $7.21 billion, from last year's $6.47 billion. Analysts expected $7.4 billion in revenue, however. The company said comparable store sales grew 0.1%. Shares of the company were falling 4.5% to $42.30 according to Instinet. Mark Mandel, an analyst with Blayclock & Partners, believes the company's stock is being pressured in part because comparable store sales grew less than expected. The company had previously guided a 2% to 4% gain. But, Mandel said, "April was terrible in terms of weather" and that had a lot to do with the essentially flat same-store results. The company would have liked stronger sales, he said, but Mandel doesn't believe it's anything to worry about long term. "The housing industry looks solid," he said. Additionally, investors may be waiting for rival Home Depot ( HD) to report its quarterly earnings on Tuesday, he concluded. Looking to the second quarter, the company expects a 13% increase in revenue and comparable store sales to grow by 2% to 4%. Lowe's expects to earn 68 cents to 70 cents a share, in line with analyst's consensus estimate of 69 cents a share. The company earned 59 cents a share in last year's second quarter.