Quantification of Carbon Emissions of Building Decoration Processes

Abstract

The continuous growth in building decoration activities has led to significant energy and material consumption, increasing carbon emissions in the construction sector. Existing literature frequently overlooks the carbon impact of building decorations. This study employs the life cycle assessment (LCA) method to quantify the carbon emissions associated with building decorations across five typic building types: residential, hospital, educational, sports cultural, and office buildings. Data were gathered using a mix of field investigations, document reviews, and semi-structured interviews, ensuring comprehensive coverage of all life cycle stages. The results reveal that carbon emission intensities of the studied building decorations ranged from 70.01 to 298.79 kg CO₂ eq/m², with the lowest emissions found in educational buildings and the highest in sports and cultural buildings. The decoration material production stage consistently emerges as the major contributor to emissions, accounting for over 50% of the life cycle of carbon emissions across all building types. The transportation stage also represents a significant share, contributing 18.6% to 24.5% across the building types. It also indicates that ceiling engineering as well as wall and column engineering are the primary carbon emission sources in terms of decoration activities. This study systematically compares the carbon emission characteristics of building decorations across multiple building types, addressing a gap that has been largely overlooked in the existing literature. It highlights the key sources of carbon emissions and proposes targeted mitigation strategies. The findings also suggest future research directions, including the application of innovative low-carbon materials, advanced construction technologies, and optimization of logistics. These insights lay a solid foundation for future low-carbon design and construction practices within the building sector.

1. Introduction

Global warming continues to be a significant challenge for modern society, with extensive and profound effects on the sustainable development of the global ecosystem. The significant rise in greenhouse gas (GHG) emissions is broadly acknowledged as a key driver of global warming. In response to this growing crisis, the international community took a significant step by collectively ratifying the Paris Agreement in 2015, taking critical actions [1]. Since 2014, China’s carbon emissions have been on the rise and have continued to increase steadily [2]. The widening disparity in carbon emissions between China and several developed nations has intensified international scrutiny and placed unprecedented pressure on China to address its contributions to global climate change.

As of 2020, energy consumption from the construction industry accounted for 12% of total final energy usage and was responsible for 20% of CO₂ emissions related to energy [3]. The ongoing urbanization process, which is particularly pronounced in China, has driven extensive construction activities characterized by high resource and energy consumption. Within this context, decoration is a key factor within the construction phase, in which there is a particular focus on achieving both esthetic and functional design. However, the current state of building decoration in China is often marked by simplicity and a lack of refinement [4].

As China’s urbanization continues at an accelerated pace and the standard of living improves, the building decoration sector has entered a phase of rapid growth. This sector has emerged as one of the three major industries within China’s construction sector, serving as a crucial component of the national economy and social life. Simultaneously, the craftsmanship involved in building decoration is becoming increasingly intricate, with renovation projects occurring more frequently. This trend highlights the pressing need to tackle carbon emissions produced by the sector. The building decoration sector, as an essential part of the construction industry, plays a significant role in overall energy consumption. Thus, comprehending the effects of these activities is crucial for formulating effective mitigation strategies. The increasing focus on carbon emissions within the construction industry serves as the impetus for further research, particularly regarding building decorations, which have been largely overlooked in past research. Given the rapid growth of urbanization and the escalating need for building renovations, it is imperative to develop a comprehensive carbon assessment framework for building decorations. Addressing this issue can provide a solid foundation for achieving sustainability with regard to decoration. This study seeks to address this gap by exclusively focusing on the quantification of carbon emissions from building decorations, thereby offering insights that are crucial for advancing low-carbon design strategies. In recent years, the carbon emissions associated with decoration have increased significantly, encompassing both direct emissions from operational processes and indirect emissions from material production [5].

In addressing the issue of carbon emissions, China has established the “carbon peak and carbon neutrality” policy, underscoring its proactive commitment to combating climate change and reducing emissions. A comprehensive understanding of the carbon emissions resulting from building decorations is crucial for implementing this strategy and achieving a net-zero society [6,7]. In the context of decorations, carbon emissions include not only the direct emissions from operational activities but also the emissions linked to the production and transportation of decorative materials from factories to construction locations, construction processes, and demolition or removal of these decorative elements at the conclusion of their life cycle. These indirect emissions within the building decoration supply chain are referred to as embodied emissions [8,9]. Nwodo and Anumba (2019) argue that, from a holistic life cycle perspective, building decorations encompass four distinct stages: production, construction, operation, and demolition [10]. Of all stages, the operational phase has the highest contribution to emissions [11]. Enhancing energy efficiency offers the potential to reduce carbon emissions during this phase [12,13,14]. Nevertheless, the link between embodied carbon and material production and transportation has also become increasingly evident [15]. Lowering the embodied carbon in building decorations has therefore become a crucial approach to achieving carbon neutrality [16]. Zhang and Wang (2023) proposed that utilizing low-carbon materials and optimized building design are effective strategies for reducing embodied carbon [17]. For example, replacing conventional materials like concrete and steel with biomass alternatives, such as wood products, can lower embodied carbon by roughly 70% [18,19].

Yu et al. (2021) applied an input–output method to determine carbon emissions among different sectors, considering the cascading effects across multiple industries [20]. Zhao et al. (2023) applied the STIRPAT method to evaluate carbon emissions associated with infrastructure construction, incorporating both carbon-intensive elements and carbon-reduction factors. They also projected future carbon emission peaks associated with infrastructure construction in Liaoning Province [21]. Liu et al. (2020) developed a comprehensive carbon emissions model for buildings by combining emissions factor calculations with LCA, significantly enhancing the accuracy and precision of carbon emissions estimates over the entire building lifespan [22]. Wang et al. (2022) examined the carbon emissions associated with decoration waste located in the Greater Bay Area, employing the LCA method [23]. Similarly, Wu et al. (2023) utilized an LCA-based method, offering an in-depth analysis of emissions contributions at each phase [24]. However, despite these advancements, a notable research gap persists when it comes to systematically comparing the carbon emission profiles of various building types and their specific decoration subsections, particularly with regard to emission intensities and main emission sources across their full life cycles.

This study seeks to systematically calculate the carbon emissions across various life cycle stages for various building types. This study concentrates upon analyzing the carbon emission intensity and primary sources for each building type over the whole life cycle. Additionally, the study will explore the carbon emissions associated with different decorative subsections within various building types to identify key high-emission processes. Unlike previous research, which has primarily focused on operational phases or isolated aspects of building emissions, this research incorporates all life cycle stages of building decoration, employing an LCA approach to identify primary emission sources and propose targeted carbon reduction measures.

2. Literature Review

2.1. Impact of Building Decorations on the Environment

The rise in GHG emissions has contributed to global warming, resulting in abnormal climate changes and ozone layer depletion, which have profoundly affected human life [25]. Consequently, the rise in GHG emissions is considered one of the most critical environmental impacts associated with building decorations. Despite often being neglected, building decoration is vital to environmental sustainability, significantly impacting the carbon footprint of buildings [5]. Material choices and design strategies not only define the esthetic quality of a building but also have a substantial effect on carbon emissions [5]. The adoption of sustainable materials, including recycled or renewable resources, in building decoration can substantially reduce the environmental impact, offering a stark contrast to the high carbon footprint associated with traditional materials [26]. These sustainable alternatives not only lower direct carbon emissions during production and disposal but also enhance buildings’ overall energy efficiency [26]. Previous research has clearly established that building decorations, as integral components of buildings, inevitably exert substantial influence on the surrounding ecosystems and human well-being [27]. CO₂ emissions, broadly acknowledged as the main factor driving the increase in GHG, are a major contributor to climate change. Moreover, global CO₂ emissions are anticipated to keep increasing in the near future, highlighting the urgent need to address and mitigate these emissions to combat climate change [28]. Prior studies have employed various strategies to reduce CO₂ emissions related to building decoration, utilizing sustainable materials, and implementing optimized structural design strategies. These strategies aim to minimize CO₂ emissions while balancing environmental performance, safety, and economic feasibility, often utilizing methods that convert material quantities into CO₂ emission equivalents [25,29].

To achieve a thorough understanding of the environmental effects linked to building decorations, Zhao et al. (2023) proposed an Em-CEF model that integrates carbon emission factor (CEF) with energy analysis methods, effectively addressing the lack of a comprehensive carbon emission factor database. Their findings highlight the potential of prefabricated structures to mitigate environmental impact and reduce carbon emissions, surpassing both traditional and green building decoration methods [26].

Wang et al. (2021) identified a notable increase in decoration and renovation waste (DRW) generation in recent years, with the majority of this waste ultimately ending up in landfills. To address the growing DRW challenge and mitigate its environmental impact, their study proposed enhancing recycling rates and promoting the adoption of prefabricated decoration as effective strategies [5]. Sun et al. (2020) emphasized the necessity of establishing comprehensive sorting facilities to minimize environmental impact and risk [30]. Zhang et al. (2020) investigated the influence of various factors, including economic development, on CO₂ emissions in China’s transportation sector [31]. The authors recommend that China implement policies aimed at fostering innovation within the transportation sector to effectively reduce CO₂ emissions [31].

However, current research on the environmental impact of building decoration primarily concentrates on specific elements such as choosing materials and optimizing design strategies, lacking a systematic comparison of carbon emission intensity and primary sources across decorations in different types.

2.2. Life Cycle Assessment

LCA is a scientific methodology that is applied to quantify the environmental impacts throughout the entire lifespan of products, processes, or activities [32,33]. The CEF method, endorsed by the United Nations Intergovernmental Panel on Climate Change (IPCC), calculates carbon emissions by analyzing energy use per unit, and is extensively used to evaluate the sustainability of buildings [34]. To obtain CO₂ emission data for building materials, the process-based LCA method is employed to assess and quantify emissions from each material during the manufacturing process, thereby creating a comprehensive database [35]. LCA serves as a robust approach for the comprehensive evaluation of buildings’ long-term carbon emissions [33]. Earlier studies have indicated that the operational stage of buildings decoration is the leading source of CO₂ emissions, primarily due to the substantial emissions associated with energy production for equipment operation. Additionally, it is crucial to recognize that the operational phase spans the longest duration within the building’s entire life cycle, emphasizing its critical role in efforts to reduce CO₂ emissions [26,36,37].

Yu et al. (2014) quantified carbon emissions and the energy usage of nine common decorative materials during the decoration process [38]. Similarly, Wu et al. (2023) employed the LCA method to assess carbon emissions at all stages of building decoration in a single office building. Their findings revealed that the operational phase was responsible for the largest proportion of carbon emissions [24].

Although previous studies have employed LCA methods to calculate the carbon emissions of buildings, research specifically focused on carbon emissions from building decorations remains relatively scarce. Additionally, few studies have systematically compared the carbon emissions of various decorative subsections across different building types. These subsections may exhibit significant differences in carbon emissions depending on the building type, highlighting the importance of optimizing strategies for specific subsections to effectively reduce carbon emissions. This study has established an assessment framework for carbon emissions related to building decoration processes. The LCA methodology was applied to quantify emissions throughout each stage of the life cycle for various building types. Subsequently, our research investigated the carbon emission characteristics of various decorative subsections within different building types.

3. Method

LCA offers comprehensive environmental data pertinent to product design [39,40]. Different features of inventory analysis allow for the classification of LCA methods into three types: (1) process-based LCA, which collects data item by item from the ground up, offering higher precision and reliability; (2) hybrid LCA, and (3) input–output LCA. The process-based approach is noted for its meticulous data collection, maintaining an elevated standard of accuracy and trustworthiness in environmental assessments. LCA research encompasses four distinct phases: (1) goal and scope definition, in which research goals are specified and system boundaries established; (2) life cycle inventory analysis, which details the flows of materials and energy within defined boundaries; (3) life cycle impact assessment, which evaluates the ecological effects linked to material use and energy exchanges; and (4) interpretation of life cycle results, providing detailed analyses to inform decisions and formulate enhancement measures. This method is considered to be effective for pinpointing environmental hotspots and offering direction for research in related domains [41,42]. This LCA investigation is in accordance with the ISO 14040 standards, consisting of four key phases: setting study objectives and scope, developing a life cycle inventory, conducting an impact evaluation, and analyzing the results [33,43]. In our study, we thoroughly examined the inputs and outputs of building decoration. We used kg CO₂ eq as a measure of adverse output, employing it as an index to assess environmental impacts. The analysis spanned five distinct building types, offering insights into the varied emission profiles across various life cycle stages.

Applying the LCA method, combined with statistical approaches such as CEF calculations, allows for an in-depth and thorough insight into the carbon emissions linked to building decoration. These statistical techniques help with the accurate quantification of emissions throughout various stages of the life cycle, thereby ensuring that the results are based on a sound and systematic evaluation process. Additionally, the process-based LCA method enables precise data collection and analysis, which is crucial for understanding the specific impacts of various materials and processes on carbon emissions. By using these statistical tools, the study provides a clear and reliable basis for the proposed carbon reduction strategies.

3.1. System Boundary

In line with the principles established in the GB/T 24040-2008 [44], our research establishes the scope for building decoration systems, comprising five distinct stages. Figure 1 illustrates the system boundary for building decoration: (1) the production stage—encompassing carbon emissions from resource extraction, transportation, and processing, as well as energy consumption during the utilization of raw materials; (2) the transportation stage—reflecting carbon emissions generated by vehicles while transporting decoration materials originating at manufacturing locations or suppliers to construction locations; (3) the decoration stage—taking into account emissions produced during the decoration phase, which are mainly ascribed to labor-intensive tasks and the energy consumed by construction equipment; (4) the operation stage—representing the carbon emissions produced by energy consumption for lighting, automated systems, and other electrical infrastructures; and (5) the end-of-life stage—including carbon emissions from labor and dismantling machinery operations during the demolition phase, accounting for electricity use, but excluding emissions related to waste transport, landfill disposal, and recycling activities.

3.2. Inventory Analysis of the Life Cycle

Drawing upon the comprehensive life cycle coverage of building decoration, this study gathered data from each of the stages and the overall carbon emissions from decoration results from the cumulative emissions across all stages, which are presented in Equation (1). The carbon emissions per unit area are calculated using Equation (2) (C_et)

$$C_{et}=C_{ep}+C_{es}+C_{ec}+C_{eo}+C_{ee}$$

(1)

$$C_I=C_{et}/S_a$$

(2)

In which $C_{et}$ denotes the cumulative carbon emissions attributed to building decoration. C_ep, C_es, C_ec, C_eo and C_eo correspond to carbon emissions linked to production stage, transportation stage, decoration stage, operation stage, and end-of-life stage, respectively (kg CO₂ eq); $C_I$ (kg CO₂ eq/m²) stands for the per unit area carbon emissions linked to decoration. S_a (m²) denotes the decoration area. The main list of materials is presented in

Table 1. The carbon emission of the primary material.

Type	Item	Consumption	Carbon Emissions (kg)
Residential building	Mortar	1072 t	203,790
	Concrete	97.2 t	71,920
	Tile	77.9 m3	65,930
	Steel	1.6 t	5990
	Gypsum	59.8 m3	48,000
	Brick	143.7 m3	42,000
	Stone	39.0 m3	12,000
	Glass	2.0 m3	6000
	Paint	1.5 m3	6000
	Putty powder	28.6 t	6000
	Iron	3.9 m3	6000
	Timber	103.9 m3	78,000
	Aluminum	1.2 t	1300
Hospital	Mortar	2796 t	531,300
	Concrete	49.5 t	36,600
	Tile	259.9 m3	219,900
	Steel	48.5 t	183,200
	Gypsum	159.9 m3	128,200
	Brick	188.4 m3	55,000
	Stone	774.6 m3	238,200
	Glass	10.2 m3	36,600
	Paint	8.3 m3	34,300
	Putty powder	261.7 t	55,000
	Iron	35.9 m3	55,000
	Timber	3366.3 m3	274,800
	Aluminum	16.3 t	18,300
Educational institution	Mortar	352.1	66,900
	Concrete	6.2 t	4600
	Tile	32.7 m3	27,700
	Steel	6.1 t	23,100
	Gypsum	20.1 m3	16,100
	Brick	23.7 m3	6900
	Stone	97.5 m3	30,000
	Glass	1.3 m3	4600
	Paint	1.2 m3	4800
	Putty powder	33.0 t	6900
	Iron	4.5 t	6800
	Timber	46.1 m3	34,600
	Aluminum	2.1 t	2300
Sports and culture building	Mortar	3159 t	600,200
	Concrete	363.6 t	269,100
	Tile	244.7 m3	207,000
	Steel	21.9 t	82,800
	Gypsum	206.4 m3	165,600
	Brick	496.2 m3	144,900
	Stone	605.8 m3	186,300
	Glass	17.3 m3	62,100
	Paint	15.1 m3	60,100
	Putty powder	295.7 t	61,300
	Iron	27.1 m3	41,400
	Timber	193.1 m3	144,900
	Aluminum	55.3 t	65,100
Office building	Mortar	1831 t	348,000
	Concrete	210.8 t	156,000
	Tile	141.8 m3	120,000
	Steel	12.7 t	48,000
	Gypsum	119.7 m3	96,000
	Brick	287.7 m3	84,000
	Stone	351.2 m3	108,000
	Glass	15.0 m3	36,000
	Paint	8.7 m3	37,000
	Putty powder	190 t	42,000
	Iron	15.7 m3	24,000
	Timber	112 m3	84,000
	Aluminum	35.3 t	39,600

.

3.2.1. Production Stage

During this phase, the main sources include the use of decoration materials and the energy consumed during their production, notably encompassing the implicit carbon emissions linked to various material types. Equation (3) is used to measure carbon emissions.

$$C_{ep}={\sum }_{i=1}^n{M}_i{F}_i$$

(3)

In which M_i (t) signifies the consumption of a specific material i; F_i (kg CO₂ eq/m³, kg CO₂ eq/t) denotes the CEF for the material i; n is the material quantity.

3.2.2. Transportation Stage

At this stage, major sources of emissions include fuel used by vehicles transporting materials to construction locations. Equation (4) is used to measure carbon emissions.

$$C_{es}=E_i{D}_i{T}_i$$

(4)

In which E_i (unit: t) represents the consumption resulting from material i being transported; D_i represents the transportation distance for material i; T_i represents the CEF of moving 1 kg of material over one kilometer, based on the transportation method related to material i.

3.2.3. Decoration Stage

Carbon emissions at this stage primarily include those resulting from labor activities and power usage of decoration machinery. Carbon emissions are calculated using the formula presented in Equation (5).

$$C_{ee}={\sum }_{i=1}^n{L}_i{F}_{li}+{\sum }_{i=1}^n{P}_i{F}_{pi}$$

(5)

where L_i (unit: man-day) represents the overall man-days required for comprehensive labor activities, F_li (kg CO₂ eq/(man-day)) represents the CEF associated with each extensive laboring man-day, P_i (kWh, kg) denotes the overall power usage of machine i and F_pi (kg CO₂ eq/kWh, kg CO₂ eq/kg) represents the CEF associated with the power usage of machine i.

$$P_i={\sum }_{i=1}^n{Q}_{pi}{R}_{pi}$$

(6)

where Q_pi (shift) denotes the shift-specific power usage of machine i and R_pi (kg/shift, kWh/shift) represents the power usage per shift in equipment.

3.2.4. Operation Stage

With the rapid development of the building decoration sector and the increasing demand for convenience in people’s daily lives, there has been significant progress in the technology used to manufacture decorative components. Various types of electric tools, such as electric doors and electric windows, have become widely used within the sector. Additionally, the incorporation of photovoltaic technology in building decoration is now also a viable option, which can enhance energy efficiency and lower emissions throughout the operational phase. Given that carbon emissions of maintenance have minimal contributions to the overall life cycle carbon footprint of decorative components, their impact is considered to be negligible and was excluded from our analysis. The overall carbon emissions per unit building area should be measured according to Equation (7). The lifespan of decorative elements varies according to the material type and exposure conditions. For instance, under identical exposure conditions, the lifespan of paint may differ from that of ceramic tiles. Such variations are critical for accurately simulating the energy consumption throughout the operational life of these elements. In this study, the lifespan of interior decorations is set at 10 years, while exterior decorations are calculated at 25 years to better assess their overall environmental impact, based on construction documents and T/CBDA X-2022 [42].

$$C_{eo}={\sum }_{i=1}^n{A}_i{O}_{i}Y-G{K}_e\left(1-K_s\right)O_{e}Y$$

(7)

where A_i (unit: kWh) represents the annual energy consumption of the decoration components of type i with operational functions. O_i (unit: kg CO₂ eq/kWh) represents the CEF for material i, G (unit: kWh/m²) refers to annual solar radiation intensity on photovoltaic cell surfaces, $K_e$ denotes the efficiency of energy conversion in photovoltaic cells, $K_s$ refers to the loss efficiency of photovoltaic cells, $O_e$ indicates the average CEF of regional power grids, and $Y$ represents the lifespan of the building decoration.

3.2.5. End-of-Life Stage

The concluding stage in the entire life cycle is represented by the end-of-life phase. Owing to insufficient data on decoration waste management, this study omitted the disposal process in the calculations. During this stage, carbon emissions are mainly attributed to comprehensive labor activities and the power usage is associated with dismantling mechanical equipment. The method used to determine carbon emissions is provided in Equation (8):

$$C_{ee}={\sum }_{i=1}^n{L}_{mi}{F}_{li}+{\sum }_{i=1}^n{P}_{mi}{F}_{pi}$$

(8)

where L_mi (unit: man-day) represents the overall man-days required for comprehensive labor activities. F_li (kg CO₂ eq/man-day) represents the CEF associated with each complete Labor Day. P_mi (kWh) and F_pi (kg CO₂ eq/kWh) denote the total power usage of equipment i and the associated CEF for energy usage by mechanical equipment i, respectively.

3.3. Case Description

The building decoration sector primarily comprises five categories of projects, including the residential building, the hospital, the educational institution, the sports and cultural building and the office building. Figure 2 illustrates the decorative designs for five building types. In this research, the annual per-unit area carbon emissions are calculated for these five project types. Considering data availability, this study selects government-funded decoration projects as the subject for carbon emissions calculation.

3.3.1. The Residential Building

A residential building in Shenzhen was selected as the case study project for this type of building (Figure 2a). The project includes an underground garage, civil defense facilities, guest rooms, ancillary rooms, sunken courtyards, equipment rooms, and more. The project encompasses a total construction area of 6500 m², with a construction period from April 2020 to March 2021, spanning a total of 12 months.

3.3.2. The Hospital

This study selected a hospital decoration project in Shenzhen City as a case study for calculating the hospital’s carbon emissions (Figure 2b). This hospital has more than 30 departments, including obstetrics, gynecology, neonatology, pediatrics (including pediatric surgery), a reproductive medicine center, a reproductive immunology comprehensive department, and others. It serves as an integrated institution for medical care, healthcare, teaching, research, and prevention, and is affiliated with multiple higher education institutions. The project commenced in January 2019 and was completed in February 2020, with a total construction period of 14 months with an overall construction area of 38,500 m².

3.3.3. The Educational Institution

A university decoration project located in Shenzhen was selected as a case study for measuring the carbon emissions of an educational institution (Figure 2d) The university covers an approximate area of 3143 m³ and encompasses 16 different colleges and departments. For the purpose of this study, we focused on the Student Services Center within the selected case project, covering a total built area of 5042 m². The construction duration spanned from March 2021 to November 2021, totaling 9 months.

3.3.4. The Sports and Cultural Building

A performing arts center in Shenzhen was selected as the case study for calculating carbon emissions (Figure 2c). This center includes a 1500-seat grand theater and a 452-seat concert hall. The stage machinery, lighting, and sound systems are all configured to international first-class standards, capable of accommodating a wide range of professional performances and business activities, including domestic and international theater, dance, symphony concerts, pop concerts, and large conferences. The case study examines the interior decoration project of the performance center, covering the ground floor, basement, and second floor. The construction area for this case study is 10,715 square meters, and the construction period spanned from March 2017 to December 2020, totaling 46 months.

3.3.5. The Office Building

To maintain the accuracy and representativeness of the calculations in this office building case study (Figure 2e), taking into layout and configuration of the office spaces, the current case study focuses on an office building comprising 4 podiums, 4 basements and 4 tower blocks. The built area is 9741 m², and the construction period extends from April 2020 to October 2021, spanning a duration of 19 months.

3.4. Data Collection

The inventory assessment employed a mix of field investigations, desk research, and semi-structured interviews to gather comprehensive data. Specifically, desk research provided detailed insights into the categories and the use of building decoration materials was derived from resources specific to each project, such as decoration material manuals, bills of quantities, and construction organization plans. The criteria for material selection are outlined as follows: considering the safety, visual appeal, and cost-effectiveness of the materials in a comprehensive manner. Meanwhile, the CEF data were acquired using the building decoration carbon emissions calculation standard in Shenzhen [45].

Emissions generated while transporting decoration materials should be calculated during the transport stage, including direct emissions from moving materials between production locations and construction locations. In this case study, a default transportation distance of 500 km and a default transportation mode using a lightweight petrol-powered truck (2 t) were considered. The corresponding CEF for the transportation stage is sourced from the building carbon emissions calculation standard [46]. Labor man-days and decoration quantities were obtained from design blueprints, construction plans, operational schemes, and actual records. Time rating data were sourced from construction labor productivity metrics [47]. Data concerning shift usage, energy usage per shift, and carbon emission factors were determined through the building carbon emissions calculation standard [46]. The guidelines for calculating equipment shift expenses were derived from projects carried out in Guangdong [48]. The decoration machinery includes various types of equipment such as cutting machines, concrete vibrators, electric hammers, grinders, and more. Data from surveys were collected to evaluate the carbon emissions linked to decoration activities across different building types (presented in

Table 2. Sources of data on carbon emissions produced by decoration.

Item	Data Sources
Decoration area	Field investigation, construction organization plans and bill of quantities
Consumption of materials	Field investigation, construction organization plans and bill of quantities
Carbon emissions factor	T/CBDA X-2022
Transportation distance	Semi-structured interviews and field investigation
CEF of energy	GB/T51366-2019
Comprehensive laboring	Semi-structured interviews and field investigation
CEF of mechanical equipment	Building carbon emissions calculation standard

).

3.5. Decoration Subsection for Each Building Type

In this study, to clearly identify the critical phases affecting carbon emissions in various types of building decorations and provide key insights for subsequent carbon reduction strategies, an extensive evaluation of carbon emissions was undertaken from different subsections of decoration across various building types. The specific subsections are listed in

Table 3. Various subsections of building decorations across different building types.

Type	Subsection
Residential building	Bathroom ancillary engineering (BAE)
	Door and window engineering (DWE)
	Furniture engineering (FE)
	Floor engineering (FEE)
	Wall and column engineering (WCE)
	Ceiling engineering (CE)
	Others
Hospital	Baseboard installation (BI)
	Door and window engineering (DWE)
	Floor engineering (FEE)
	Wall and column engineering (WCE)
	Ceiling engineering (CE)
	Others
Education institution	Furniture engineering (FE)
	Door and window engineering (DWE)
	Bathroom ancillary engineering (BAE)
	Wall and column engineering (WCE)
	Ceiling engineering (CE)
	Floor engineering (FEE)
	Others
Sports and culture building	Bathroom ancillary engineering (BAE)
	Door and window engineering (DWE)
	Furniture engineering (FE)
	Ceiling engineering (CE)
	Wall and column engineering (WCE)
	Floor engineering (FEE)
	Others
Office building	Bathroom ancillary engineering (BAE)
	Door and window engineering (DWE)
	Floor engineering (FEE)
	Podium and elevated floor ceiling engineering (PEFCE)
	Ceiling engineering (CE)
	Wall and column engineering (WCE)
	Others

. Through this analysis, we were able to pinpoint the primary sources of carbon emissions within each type of building decoration, thereby offering a scientific basis for formulating targeted carbon reduction measures. This method guarantees that our strategies are supported by empirical data, thereby improving their efficiency in minimizing the carbon emissions linked to building decorations.

3.6. Data Limitation

In investigating the LCA of building decoration, this study encountered challenges related to project variability, data complexity, and data diversity. The calculation process involved a broad spectrum of data, which created challenges associated with data acquisition feasibility and the absence of a comprehensive statistical foundation.

For the characterization of cases, standardized building decorations from five different types of buildings were primarily utilized as representative models for calculations in this research. Due to resource constraints, comprehensive investigations and detailed calculations for every individual decoration project were not feasible.

Within the LCA of building decoration, the variability in conditions unique to each project, the diversity and intricacy of data types, and the extensive range of necessary data add significant complexity to the analysis. Furthermore, the difficulties in data acquisition, combined with the lack of a robust statistical foundation, add complexity to the evaluation process. The main sources of uncertainty in the data quality relevant to this research are outlined as follows: (1) The majority of data for this study were obtained through field research, while some input–output and CEFs were derived from existing research. The main sources of error stemmed from inconsistencies in system boundaries and temporal boundaries used in the study. Given the relatively recent establishment of LCA databases, the dynamic changes in emission factors were not reflected in a timely manner, assuming a normal distribution for these data. To evaluate uncertainties, this study employed the Monte Carlo simulation method, conducting 10,000 iterations with a confidence level set at 95%. This approach provides statistical support for the reliability of the findings, facilitating a more accurate understanding of carbon emissions within the building decoration. (2) For the characterization of case studies, this research selected five typical standardized building decoration cases for predictive analysis. However, not all decoration projects underwent detailed surveys and calculations. Owing to insufficient transportation data, this study presumed that materials were delivered to the construction site using a fully loaded light gasoline truck (2 tons). To account for uncertainties, a Monte Carlo simulation method was employed, assuming uniform distribution of transport distances, with 10,000 computations performed at a 95% confidence level. This approach aims to enhance the reliability of results and provide a more scientific basis for related decision-making.

In this study, validation relied mainly on on-site investigation and examination of project records. Specifically, detailed data from construction organization manuals, bills of quantities, and design drawings were used, along with information gathered from site visits, to verify the carbon emission intensity and carbon emissions in decoration projects across various building types. Due to the variations in the areas of different building decoration projects, comparing the carbon emission levels across different building types presents a challenge. To minimize the impact of these area differences, this study employs carbon emission intensity as the primary metric for comparing the carbon emission levels of building decorations.

4. Results and Discussion

4.1. Carbon Emissions from Building Decorations Across the Life Cycle for Five Building Types

Utilizing the developed LCA model and the life cycle datasets across all stages, the overall carbon emissions, carbon emission intensity, and stage-wise emissions were determined for the decoration of five different building types.

This study quantifies the carbon emission intensities across various building types, describing the emissions generated at every phase of the building decoration process, shown by Figure 3a,c and Table S1. The evaluation reveals that the production phase constitutes the primary contributor to carbon output for all building types examined, consistently accounting for over 50% of total life cycle emissions. Remarkably, in educational institutions, the production stage alone constitutes 65.3% of the emissions, featuring a carbon emission intensity of 45.75 kg CO₂ eq/m². Statistical data indicate that the transportation stage also represents a significant portion of the total emissions, with percentages ranging from 18.6% to 24.5% across different types. Emissions from both the production and transportation stages contribute to more than 70% of the total carbon output in all analyzed building types, with the findings for educational institutions and sports and cultural buildings being particularly notable, as for these building types, these stages collectively comprise over 80% of overall emissions. This finding highlights the pivotal role of these stages in carbon emissions of building decorations, and the significant finding that highlights the significance of selecting appropriate materials with regard to the overall environmental impact of building decorations. Similarly, the transportation stage has a marked contribution to emissions, highlighting the carbon-intensive nature of material logistics in construction. Following this, the decoration stage displays a substantial emission contribution during the end-of-life stage, with the operation stage trailing behind, respectively. Notably, the operation stage has the smallest contribution to carbon emissions, a finding that contradicts previous assumptions positing it as a major emitter [26]. This inconsistency can be elucidated through the “Unified Standard for Constructional Quality Acceptance of Building Engineering (GB 50300-2013)”, which explicitly specifies that building decoration does not include systems such as plumbing, ventilation and air conditioning, or elevators. Since these systems are not categorized under decoration, their energy consumption and associated emissions are not accounted for in the operational phase, resulting in significantly lower reported emissions data.

As shown in Figure 3b, the carbon emission intensities of decorations across five different building types are presented. The results indicate that sports and cultural buildings exhibit the highest carbon emission intensity from decoration activities, at 298.79 kg CO₂ eq/m². Office buildings follow, with an emission intensity of 215.38 kg CO₂ eq/m², which deviates from the previously assumed value of 254.5 kg CO₂ eq/m² [26]. The discrepancy may be imputed to factors mentioned earlier, such as the exclusion of air conditioning and elevator systems from the decoration calculations, leading to significantly reduced emission figures. Residential buildings show an emission intensity of 160.29 kg CO₂ eq/m². In contrast, hospitals and educational institutions demonstrate lower intensities, at 94.15 kg CO₂ eq/m² and 70.01 kg CO₂ eq/m². These variations reflect the diversity in functional requirements across different building types, resulting in significant disparities in their decoration-related carbon emissions.

4.2. Carbon Emissions of Decoration Subsection for Each Building Type

In this study, to effectively pinpoint the key phases influencing carbon emissions in various building decoration types and offer crucial insights for strategies for reducing carbon emissions in future, a comprehensive analysis was employed to assess carbon emissions from different decoration components across various building types. The specific subsections are listed in Table 3. Through this analysis, we were able to pinpoint the primary factors behind carbon emissions within each type of building decoration, thereby providing a scientific basis for formulating targeted carbon reduction measures.

4.2.1. Residential Building

Figure 4a meticulously illustrates the carbon emissions and intensity of various sub-projects within a residential building decoration project. Among these, ceiling engineering displays the most significant carbon output, reaching 312,650 kg CO₂ eq with an emission intensity of 48.1 kg CO₂ eq/m². The wall and column engineering follows closely behind, emitting 290,070 kg CO₂ eq and exhibiting an intensity of 44.63 kg CO₂ eq/m². In contrast, bathroom accessory engineering shows the lowest emission figures, with 28,980 kg CO₂ eq and an intensity of 4.46 kg CO₂ eq/m². These data emphasize the critical role of particular construction stages in the overall environmental footprint of residential buildings. The high emissions from ceiling and wall engineering are primarily attributed to the extensive application of materials with high demands for energy consumption, like gypsum board, cement, and mortar. The significant discrepancy in emission levels across different subprojects underscores the need for targeted material optimization and construction practices to mitigate environmental impacts.

4.2.2. Hospital

As displayed in Figure 4b, the diagram illustrates an exhaustive account of carbon emissions volume and intensity for various subsections within the hospital building decoration project. Similarly to the residential building project, the ceiling engineering as well as wall and column engineering of the hospital show significant carbon outputs. Specifically, ceiling engineering generates 1,174,380 kg of CO₂ eq, with an emission intensity of 30.50 kg CO₂ eq/m². Wall and column engineering follow closely behind, with carbon emissions totaling 980,100 kg CO₂ eq and an intensity of 25.46 kg CO₂ eq/m². The elevated emissions from these subsections are also primarily due to the extensive use of cement and mortar. In contrast, the baseboard installation engineering displays considerably lower emissions, amounting to 86,900 kg CO₂ eq with an intensity of merely 2.26 kg CO₂ eq/m². Ceiling engineering as well as wall and column engineering are characterized by significant emissions, and this is largely attributable to the extensive use of high-energy-consuming materials such as cement and mortar. This finding is consistent with the observed trends in residential buildings, indicating a broader pattern of high emissions associated with these materials across building types. The pronounced disparity in emissions across the subsections not only reflects varied material usage but also highlights differences in construction techniques, which are significant contributors to the carbon footprint of hospital construction.

4.2.3. Education Institution

Figure 4c also provides an in-depth summary of the carbon emissions and intensity across various subsections within the educational institution decoration project. Among these, floor engineering is particularly notable, with recorded carbon emissions of 175,720 kg CO₂ eq and an emission intensity of 34.85 kg CO₂ eq/m², which is significantly higher than other subsections, making it a major contributor to carbon emissions for this building type. Ceiling engineering also exhibits considerable emissions, amounting to 95,160 kg CO₂ eq with an intensity of 18.87 kg CO₂ eq/m².

In contrast, furniture engineering shows relatively lower carbon emissions, totaling just 1010 kg CO₂ eq with an intensity of only 0.20 kg CO₂ eq/m². These results provide a valuable understanding of the carbon emission patterns of educational facilities, highlighting the necessity for a strategic approach to material selection and construction techniques. By focusing on high-emission areas such as floor engineering and adopting lower-emission alternatives, educational institutions can significantly reduce their overall carbon emissions.

4.2.4. Sports and Culture Building

Figure 4d delineates the carbon emissions for various subsections within the sports and cultural building decorations, illustrating that the floor engineering as well as wall and column engineering subsections dominate in terms of emissions. These subsections recorded carbon emissions volumes of 1,134,850 kg CO₂ eq with intensities of 105.91 kg CO₂ eq/m², and 1,103,810 kg CO₂ eq at intensities of 103.02 kg CO₂ eq/m². The substantial emissions from these subsections reflect the significant environmental impact of using high-carbon-content materials such as steel and mortar, as well as the characteristics of large-span spaces.

In stark contrast, furniture engineering, door and window engineering, and bathroom ancillary engineering are on the lower end of emission metrics. The bathroom ancillary engineering exhibits the smallest environmental impact, with emissions totaling just 48,200 kg CO₂ eq and an intensity of 4.50 kg CO₂ eq/m². This significant variance across the sub-projects underscores the diverse effects in material choices and construction practices on the overall carbon emissions profile, indicating potential areas for targeted carbon mitigation strategies in the design and execution of future sports and cultural building projects.

4.2.5. Office Building

Figure 4e reveals that within the office building decoration project, the wall and column engineering subsection exhibits the highest carbon emissions, recording an output of 616,270 kg CO₂ eq and an intensity of 63.27 kg CO₂ eq/m². The pronounced emissions from wall and column engineering are largely attributable to the application of materials with high energy demands, like mortar and concrete. Following closely behind are the ceiling engineering and podium and elevated floor engineering, with emissions of 456,850 kg CO₂ eq and intensities of 46.90 kg CO₂ eq/m², and 432,590 kg CO₂ eq with 44.41 kg CO₂ eq/m², respectively; these emissions are largely attributable to the use of materials such as gypsum board. In contrast, the category labeled as others shows the least environmental impact, with carbon emissions amounting to only 109,910 kg CO₂ eq and an emission intensity of 11.28 kg CO₂ eq/m².

This study provides an extensive evaluation of carbon emissions across different types of building decoration projects, with an emphasis on the carbon emissions intensity of various subsections. In residential, hospital, educational, sports and cultural buildings, as well as office buildings, it was found that carbon emissions are primarily concentrated in specific subsections such as ceiling engineering and wall and column engineering. These subsections are principal emitters of carbon emissions due to their reliance on materials with high energy demands. Additionally, flooring engineering is notably significant in educational institutions, highlighting its importance in carbon emissions. These findings underscore the necessity for targeted intervention measures and offer important references for future low-carbon design and construction practices.

4.3. Recommendations for Low-Carbon Decoration

Grounded in the insights yielded by this research, carbon emissions from building decorations differ considerably among the various building types and their specific decoration subsections. It is imperative to consider the specific features unique to each building type and the distinct impacts of various decoration subsections to reduce carbon emissions. For instance, in these buildings, ceiling engineering as well as wall and column engineering are major sources of carbon emissions due to their extensive use of energy-demanding materials, such as gypsum board, cement, and mortar. By selecting low-carbon alternatives and optimizing material usage in these areas, significant carbon emission reductions can be achieved. In educational institutions, where floor engineering is the primary contributor to carbon emissions, substituting traditional flooring materials with low-carbon options like bamboo or recycled composites can substantially mitigate environmental impacts [24]. Sports and cultural buildings, characterized by large-span spaces, require tailored strategies to address high emissions from floor engineering and wall and column engineering, which can be realized through innovative design techniques and the selection of sustainable materials specifically suited to such buildings [49].

Through the study of this research, high carbon emissions are a key concern across all building types in the production stage. Material choices not only affect initial carbon emissions but also long-term environmental impacts. Enhancing material performance and production processes is crucial. Using renewable, low-energy alternative materials reduces energy consumption and enhances sustainability. In complex environments like hospitals, the use of sustainable and eco-friendly materials is particularly vital, as these materials can significantly reduce carbon emissions while adhering to stringent health standards [50]. These materials are ideal for eco-friendly decorations. Optimizing logistics efficiency, such as using efficient vehicles and improving transportation infrastructure, significantly reduces carbon emissions. Local sourcing strategies can greatly shorten transportation distances and using electric vehicles for short distances further decreases emissions. During the decoration stage, since decorative machinery mainly consumes electricity, using efficient devices like AC spot welders and electric air compressors significantly lowers energy use [24]. Implementing green construction plans and optimizing site management and technical planning reduces unnecessary labor and resource waste. By scaling and industrializing component production, prefabricated decorations only require transporting these components to the assembly site, thereby reducing excess carbon emissions during construction [51]. During the operation stage, transitioning to clean energy options like wind energy or solar power, as well as enhancing the efficiency of building decor components like smart windows and doors, significantly reduces carbon emissions during daily operations [52]. The intelligent control systems enhance energy utilization efficiency and reduce carbon emissions [53]. Finally, in the end-of-life stage, meticulous deconstruction strategies are vital for achieving optimal carbon emission efficiency. Optimizing deconstruction processes and labor deployment minimizes energy consumption related to nighttime operations, like lighting. Planning building interiors early can reduce the scope and frequency of future renovations or demolitions, thus lowering carbon emissions [54]. Encouraging the recycling and reuse of building materials, particularly in projects where efficient recycling is achievable, further strengthens carbon reduction initiatives. This research indicates that embodied carbon emissions originating from the production and transportation of decoration materials are significant. To effectively reduce these emissions, an integrated approach involving collaboration across disciplines—including designers, researchers, material manufacturers, and policymakers—is recommended. Due to the limited effectiveness of single strategies, a combination of mitigation strategies, especially in the advancement of low-carbon material technologies, is advocated. This collaborative effort can significantly decrease the reliance on high-carbon materials such as concrete and steel, as well as minimize unnecessary transportation, thereby reducing excess carbon emissions. Such a systematic and cooperative reduction path is expected to greatly enhance the carbon reduction efficiency in the building decoration industry [39].

To achieve meaningful reductions in carbon emissions from building decoration, the government should develop subsidy policies to encourage the use of low-carbon building materials, like bamboo or recyclable composite materials. Optimizing the supply chain for building materials can also substantially decrease carbon emissions, especially by using materials from local sources to reduce transportation distances. Additionally, promoting the use of electric vehicles for short-distance transportation can contribute to emissions reduction. Encouraging the industrialized production of building decoration components, such as prefabricated elements, can significantly reduce on-site emissions by minimizing the energy consumption associated with traditional on-site construction. Strengthening regulations that promote sustainable practices within the construction industry is essential for reducing the carbon footprint of building decorations. Future research could explore a broader geographic range to validate these findings across different environmental and regulatory contexts. Additionally, studies could focus on quantifying the economic benefits of low-carbon practices to support policy development, ensuring that sustainability efforts are both environmentally and economically viable. Additionally, further investigation is required to assess the economic feasibility of various low-carbon interventions to provide a balanced view of their applicability and costs in the building decoration sector.

5. Conclusions

With the ongoing growth of building decoration activities, energy and material consumption has markedly increased, resulting in higher carbon emissions within the construction sector. To tackle this problem, this research utilizes the LCA approach to systematically evaluate carbon emissions related to the decoration of five distinct building types: residential buildings, hospitals, educational institutions, sports and cultural buildings, and office buildings. The findings reveal that carbon emission intensities across these building types range from 70.01 to 298.79 kg CO₂ eq/m², with educational institutions exhibiting the lowest emissions and sports and cultural buildings the highest.

The production stage consistently stands out as the primary source of carbon emissions, representing more than 50% of the total life cycle emissions for all building types, with educational institutions reaching as high as 65.3%. Similarly, the transportation stage contributes a substantial portion, ranging between 18.6% and 24.5% of the aggregate emissions contingent on the building category.

Further analysis of specific subsections, such as ceiling and wall engineering, reveals that these elements, due to their reliance on energy-intensive materials, are the primary sources of emissions. Floor engineering stands out as a significant contributor in educational institutions. These findings underscore the necessity for targeted intervention strategies, particularly in material selection and construction process optimization, enhance power efficiency, and reduce the reliance on high-emission materials.

This study offers a thorough assessment of carbon emissions during the decoration process for different building types, providing detailed insights into the carbon emission features across diverse phases of the life cycle and subsections of various decoration projects. This detailed investigation addresses previous research gaps in the field and offers in-depth knowledge on carbon emissions specific to different building types. By revealing the primary sources and distribution of carbon emissions within the decoration processes, this research introduces new perspectives ways to effectively reduce carbon emissions in building decoration projects. This research lays a solid groundwork for future low-carbon design initiatives and construction practices, advancing sustainability in the construction sector. By pinpointing the primary stages and components that make significant contributions to carbon emissions, this research highlights the critical importance of strategic interventions in design and construction practices. These findings offer a comprehensive basis for developing precise and scientifically grounded carbon reduction strategies, which are essential for mitigating the environmental impact of building decorations.