• Material production stage

Pollutant emissions produced in this stage can be calculated based on the bill of material quantities and the life cycle inventory. A proper material loss rate has been considered in the bill of quantities, which references the Quota of Beijing Construction Project [24].

• Construction stage

The two main sources of pollutant emissions produced in this stage are construction machines and material transportation. Gasoline, diesel and electricity consumed by construction machines are calculated based on National Unified Construction Machinery Quota [25]. In the light of 2013 Statistical Yearbook of China, the average transportation distance is 181 km [2]. It is assumed that building materials are transported by trucks. The average fuel consumption level is about 101.78 L/(kt·km) [13]. The diesel consumption can be calculated as follows:

$$Q = \sum\_{i} m\_{i} \times L\_{i} \times q\_{m\_{i}} \tag{1}$$

where *Q* is the diesel consumption; *mi* is the mass of *i*-th material; *Li* is the transportation distance of *i*-th material, assumed to be 181 km; *qmi* is the average fuel consumption for transporting per unit material, assumed to be 101.78 L/(kt·km).

• Operation stage

Energy consumption during this stage implicates the energy and resources, including electricity, natural gas and water consumption. Since the two case buildings just completed construction, there are no actual maintenance monitoring data. Consequently, the water consumption, electricity consumption and domestic waste production for each person can only be estimated based on the local statistical yearbook [26,27], assuming that each family consists of three people. The number of apartments in the two case study buildings is 78 for Xiamen and 100 for Beijing.

Additionally, the pollutant emissions also include household waste, which can be estimated based on household waste of similar commercial buildings per unit time. For residential buildings, the energy consumption and household waste amount are influenced by per capita consumption and living habits, which can be estimated in the light of the statistical yearbook. For regions in northern China, the environmental costs caused by the consumption of coal for heating cannot be ignored.
