The building indices (BT) and public works (TP) are indices of costs of different activities in the construction sector, apprehended from 6 positions in a cost accounting process :
"cost of labor" formerly called "salaries and expenses",
"materials",
"equipment",
"energy",
"transportation",
"miscellaneous expenses",

similar to the approach "KLEMST" of the productivity economists (K = capital , L = labour, E = energy, M = materials, S = services for "miscellaneous expenses", T = transport).
Although the structure and the weighting of the indices BT and TP were periodically reviewed, the BT indices are still expressed in reference 1974 and the indices TP in reference 1975.