WASHINGTON, DC — The number of housing units in multifamily construction has hovered in the six-digit region for most of the past two decades.

The most recent count (1998) shows there were 32,000 buildings completed, which represent 314,000 housing units involved in the multifamily sector, the highest during the decade and a sign of a brisk turnaround after years of relatively poor activity.

This sector has traditionally absorbed a high percentage of air conditioning equipment and most recently (1998) the figures show an 87% saturation rate, according to the U.S. Census Department.

This is partially due to the fact that nearly half of these units are built in the South, where cooling demand is high. Only 7% of those units built last year were in the Northeast.

What's going in

This building activity represents a lot of rooftop units, outdoor condensing units, air-handling equipment, and central chilling systems.

The growth of heat pumps in this sector shows a sharp rise since 1994, from 26% to 33% — with no sign of a reversal of this trend.

Related to this heat pump use is the increase in the use of electricity as a home heating fuel, from 46% in 1994 to 55% last year.

A mirror image of this trend is seen in the decline in the use of gas, from 52% in 1994 to 44% last year.

The existing base of approximately 40 million multifamily units also represents a dynamic replacement market.

One government report estimates that about 30% of the units in this sector have central cooling, while another 30% have window air conditioners. Another 6% are heated and cooled by heat pumps.