Log Mean Divisia Index Decomposition Analysis of the Demand for Building Materials: Application to Concrete, Dwellings, and the U.K.

Dwellings are material
intensive products. To date, material use
in dwellings has been investigated mainly using economic (exogenous)
or dwelling (endogenous) drivers, with few studies comprehensively
combining both. For the first time, we identify a comprehensive set
of such drivers of demand for building materials and analyze them
using the logarithmic mean divisia index (LMDI) method. We combine
the LMDI method, the concept of dynamic material flow analysis, and
physical and monetary flows to decompose the demand for building materials
into the following six effects: material intensity, floor area shape,
dwelling type, dwelling intensity, economic output, and population.
We analyze these six effects on demand for concrete in new dwellings
in the U.K. from 1951 to 2014, classified into six dwelling types
and four subregions. Of these six effects, the material intensity
effect is the most important, overall contributing to increasing concrete
demand by +79 Mt from 1950 to 2014, while the dwelling intensity effect
plays an opposite role, overall reducing concrete demand from 1950
to 2014 by −56 Mt. The economic output effect is also significant
(+38 Mt from 1950 to 2014). A comparative analysis of the six effects
in the four U.K. nations reveals that most of the effects arise from
England, while the other nations have minor effects due to their smaller
populations. Our results show that changes to the demand for concrete
in the U.K. fluctuate and have mainly remained between ±30 Mt
year–2 from 1950 to 2014, and thus the inflows of
concrete into the in-use stock of dwellings have experienced neither
entirely increasing or decreasing trends during this period. This
study contributes to understanding changes in resource demand due
to social, economic, and technological factors and thus improves the
capability to reliably and quantitatively model the use of materials
in the built environment.

住宅建筑乃物质密集型产品。迄今为止，住宅建筑材料的使用主要依赖于经济（外生）或住宅（内生）驱动力进行研究，而将两者全面结合的研究尚显不足。本研究首次识别出一套全面的需求驱动因素，针对建筑材料的需求进行分析，并采用对数平均Divisia指数（LMDI）方法进行解析。本研究将LMDI方法、动态物质流动分析概念以及物质与货币流动相结合，将建筑材料的需求分解为以下六个效应：物质强度效应、楼面形状效应、住宅类型效应、住宅密度效应、经济产出效应和人口效应。我们对英国1951年至2014年间新住宅中混凝土的需求进行了分析，将其划分为六种住宅类型和四个次级区域。在这六个效应中，物质强度效应最为显著，总体上自1950年至2014年增加了混凝土需求+79Mt，而住宅密度效应则起到相反的作用，总体上自1950年至2014年减少了混凝土需求−56Mt。经济产出效应同样具有重要意义（自1950年至2014年增加了+38Mt）。对四个英国国家的六个效应进行比较分析显示，大部分效应源自英格兰，而其他国家的效应较小，这是由于它们的人口规模较小。我们的研究结果表明，英国混凝土需求的变化波动不定，且主要保持在±30Mt/年的范围内，因此在此期间，混凝土流入住宅使用库存的趋势既没有完全增加也没有完全减少。本研究有助于理解由于社会、经济和技术因素引起的资源需求变化，从而提升了可靠且定量地模拟建成环境中材料使用的能效。