Multifamily housing continues to improve – at least by some appearances. The National Association of Home Builders recently registered 54 on an index that measures multifamily production.

On a scale of zero to 100, the trade group found the index doing well for the eighth straight quarter, marking a high not seen in seven years.

The Multifamily Production Index (MPI) noted the rise from 51 for an index that tallies up homebuilder and developer sentiment about the state of the apartment and condo market.

For the index, the second quarter this year brought a steady improvement in perspective about the market.

Builder and developers gave a 63 to market-rate rental properties, up from 60, deepening what the NAHB release called the “longest sustained period of strength” since it launched the index in 2003.

For-sale units brought even gladder tidings: the trade group said that it went up to 41, the highest reading since fourth-quarter 2005.

“The apartment and condo housing sector is continuing on a path of steady recovery as new construction has increased to try to keep up with current consumer demand,” W. Dean Henry, CEO of Foster City, California-based Legacy Partners Residential and chairman of the multifamily leadership board.

“However, credit continues to be an issue for many developers around the country, making it difficult to keep pace with this demand,” he added.

“The strength of the MPI suggests that multifamily production is likely to increase somewhat going forward,” added NAHB Chief Economist David Crowe.

He said that multifamily production continues to see perks from a substantial recovery, with 110,000 starts up to more than 200,000 between 2009 and 2010.

“[T]here is room for further improvement before apartment and condo production return to normal, sustainable levels,” he cautioned.