Although ENR’s indexes measure the costs of non-residential buildings, the housing market has had a major impact on index movement. The ENR 20-city average yearly price for 2x4 lumber fell 4.9% by the end of 2019, while the overall Material Cost Index experienced an increase of 3.8% Both skilled and common labor saw a modest gain. As a result, the ENR Building Cost Index increased 1.7% for the year, while the Construction Cost Index rose 1.7% as well.
ENR began reporting changes in materials prices and wages systematically in 1909, but it did not establish the CCI until 1921. It was designed as a general-purpose tool to chart basic cost trends and today remains a weighted aggregate index of the prices of a constant quantity of structural steel, portland cement, lumber and common labor. This package of goods was valued at $100, using 1913 prices.