The Commerce Department said that new homes and apartments were constructed at a seasonally adjusted annual rate of 1.70 million units in April, down from a March level of 1.75 million units and 12.6% below a year ago. It was the second consecutive monthly decline. The weakness last month was centered in multifamily construction, which fell a sharp 14.1%. Analysts blamed the decline on high vacancy rates around the country and the adverse effects of the new tax law, which revoked many real estate investment benefits. Construction fell 11.4% in the West to an annual rate of 427,000 units.