CHAPTER 2
 REVIEW OF LITERATURE

 Amount of Construction Each Year

 Over the last three decades lumber consumption has increased by nearly one-third,

and structural panel use has more than doubled. The Resources Planning Act (RPA)

Timber Assessment projects that the consumption of solid wood products will continue to

grow in the future through the expansion of both construction and nonconstruction uses

due to America's growing population and increasing wealth (Adams 2002).

 It is projected that, every year for the next 50 years, 1.43 million new households

will be constructed, thus creating approximately 71 million additional separate living

units. Approximately, 1.93 million houses will also be improved each year for the next

50 years. The primary driver of the new construction and improvements is an aging,

healthy, retired population acquiring second homes (Adams 2002).

 Reflecting the trend of an aging population and the declining number of people per

household, the average size of new housing units is projected to stabilize over the next 40

years and then rise in the final decade of the projection. By 2050, the average size of a

single-family unit will increase from the current average of 2,160 square feet to 2,600

square feet. Multiple-family housing will expand from 1,000 to 1,200 square feet, and

mobile homes will grow from 1,350 to 1,950 square feet (Adams 2002). In 2004, single-

family houses had already increased to an average size of 2,225 square feet (CORRIM

2004). Since 1991, the consumption of lumber has been growing steadily. A historical

high of 68.2 billion board feet (bbf) consumed was reached in 1999 (Adams 2002).