Revisiting the Energy-Saving Behavior of Hotel Guests: An Integrated Model of TPB and NAM in Vietnam

Abstract

This paper explores the energy-saving behavior of hotel guests in the Vietnamese context. We adapted the theory of planned behavior (TPB) and the norm activation model (NAM) to develop a research model with six determinants of energy-saving intention and behavior. A self-administered online survey was implemented to collect data from hotel guests in Hanoi and Quang Ninh provinces. After 4 months, we received 253 valid responses for further analysis. SmartPLS 4.0 software was employed for structured equation model testing. Our findings showed that TPB variables and NAM variables jointly explain the energy-saving intention and energy-saving behavior of Vietnamese hotel guests. Among the three factors of TPB, subjective norms have the most substantial impact on energy-saving intention and a significant direct effect on energy-saving behavior. Meanwhile, awareness of consequences does not significantly affect personal norms, and in turn, personal norms do not directly affect energy-saving behavior. Thus, we proposed several solutions to hotel managers to promote energy-saving initiatives and attract the engagement of their guests in these initiatives.

1. Introduction

The substantial rise in global energy consumption, primarily driven by human activities, is a significant contributor to the ongoing climate crisis (J. Wang et al., 2022). The tourism and hospitality industry contributes 10% of global GDP, creating 320 million jobs, but also discharges 8% of global carbon emissions (D. Liu et al., 2023). Recent research indicates that the industry’s energy consumption is responsible for the most significant portion of 60% of carbon emissions, with a notable increase of 25–30% observed over the past few decades (Miao & Wei, 2013; Upadhyay, 2015; Q.-C. Wang et al., 2021). As a significant energy consumer, this escalation has resulted in a considerable financial burden for hotel operators, inflating operating costs by an additional 3–6% (Upadhyay, 2015). In response to sustainability and Sustainable Development Goal 7, destinations, academia, and the industry have developed various sustainable hotel operation and management strategies. As a result, alternative strategies have been implemented to promote hotels with sustainable operations and eco-friendly energy systems and design. All hotels, regardless of their sizes, are moving forward to the industry trend of green movement by promoting energy and water efficiency, waste management, and eco-friendly operation (Salehi et al., 2021). All energy-saving practices enhance guest comfort, aesthetic appeal, and, most importantly, system operation reliability, thus promoting a high-quality service environment in hotels and sustainable environmental protection by reducing harmful emissions (Cingoski & Petrevska, 2018). However, the high initial investment and maintenance costs can still pose a significant challenge for hotel innovations (Cingoski & Petrevska, 2018).

In response to the escalating environmental challenges, researchers have focused on understanding pro-environmental behaviors such as green consumption (Duong et al., 2022), energy conservation (Tang et al., 2016), and waste separation (Goh et al., 2022). Extant studies also confirmed the effectiveness of behavior-driven energy conservation strategies in hotel operations (Q.-C. Wang et al., 2021, 2023). Understanding guests’ energy-saving behavior is essential for developing and implementing effective strategies. Thus, numerous empirical studies have focused on the energy conservation behaviors of hotel guests, providing evidence for the impacts of behavioral interventions on energy savings (Han et al., 2020; Q.-C. Wang et al., 2023). However, studies on this topic are still limited in terms of the number of publications (Miao & Wei, 2013; Q.-C. Wang et al., 2021). Individuals tend to use more energy and water during their stay in hotels, compared to their homes, for their comfort (Untaru et al., 2016).

Factors affecting their changing behavior toward energy savings are examined in the existing research with an attempt to understand, e.g., psychological drivers and mechanisms driving energy-saving behaviors in hotels (Q.-C. Wang et al., 2021, 2023), pro-environmental behaviors and motivations of hotel guests (Miao & Wei, 2013), or factors affecting intentional behaviors for energy-saving by hotel guests (Untaru et al., 2016). This academic attention has contributed to a foundation framework of behavior-driven energy conservation. However, more empirical research is needed to understand this behavior in the hospitality industry, as previous studies have primarily focused on isolated factors separately in various contexts. An in-depth exploration of these behavioral processes could significantly inform the development of effective interventions to promote sustainable practices within the hospitality industry.

While various theoretical frameworks have been employed in these existing studies, the Theory of Planned Behavior (TPB) and the Norm Activation Model (NAM) have emerged as prominent models (Goh et al., 2022; Si et al., 2021). The TPB is effectively used in predicting energy-saving intentions and behaviors through its core constructs, such as attitude, subjective norms, and perceived behavioral control, whereas the NAM has been employed separately to understand the cognitive processes and social influences that affect energy-saving behavior (Rivis et al., 2009; Shi et al., 2017). The NAM’s emphasis on personal norms shaped by awareness of consequences and ascription of responsibility offers a complementary perspective that could enrich the understanding of energy-saving actions (Naeem Nawaz et al., 2022). Our study is among the few in the literature, e.g., Xuan et al. (2023), exploring the combined framework of TPB and NAM in the research model to address the multifaceted motivations behind energy-saving behaviors. Our study highlights the importance of considering not only individual attitudes and beliefs but also social norms, perceived control, and moral obligations in predicting and promoting energy-saving actions.

Despite the extensive research on environmentally friendly behaviors, there is a significant lack of studies specifically focused on energy-saving behaviors among hotel guests. Our study focuses on hotels in Vietnam as the research context. This industry is undergoing significant transformations driven by the dual pressures of economic growth and environmental sustainability (Le et al., 2023). Energy efficiency becomes increasingly critical to reaching sustainability goals as the industry grows. This study aims to explore the guests’ energy-saving behaviors within Vietnamese hotels through an integrated model that combines the TPB and the NAM. An integrated research model will provide a holistic understanding of the factors influencing energy-saving intentions and behaviors among hotel guests. Thus, this study will contribute to a deeper understanding of the psychological mechanisms that drive these energy-saving actions that promote sustainable practices among hotel guests in Vietnam. The findings of this study have significant implications for the Vietnamese hospitality industry, as they provide a framework and actionable insights for understanding the behavioral factors that influence energy-saving intentions and behaviors among hotel guests, ultimately contributing to reduced energy consumption and enhanced environmental performance in the sector.

The present paper is structured into six sections. Section 1 introduces the topic. Section 2 presents the literature review and foundations for the research hypotheses. Section 3 explains the methods. Section 4 discusses the research results. Section 5 highlights the implications and limitations of the study and suggests future research directions. Finally, Section 6 concludes the paper.

2. Literature Review and Hypothesis Development

2.1. Energy-Saving Intention and Actual Behavior

2.1.1. Energy-Saving Intention

The concept of energy-saving intention has garnered significant attention in recent research, particularly in the context of escalating energy consumption and environmental concerns. While prior research has explored energy-saving behaviors in various settings, including companies and households, the focus on energy-saving intention has been relatively limited, particularly in developing countries (Qalati et al., 2022).

Energy-saving intention is conceptualized as an individual’s readiness to perform energy-saving actions, reflecting their motivational factors and planned efforts to reduce energy consumption (Ajzen, 1991; Fatoki, 2023; Ajzen & Fishben, 1977; Hasan, 2023). The theory of planned behavior (TPB) has emerged as a prominent framework for understanding the antecedents of energy-saving intentions. The TPB posits that intentions are influenced by attitudes towards the behavior, subjective norms (perceived social pressure), and perceived behavioral control (the perceived ease or difficulty of performing the behavior) (Ajzen, 1991).

2.1.2. Actual Energy-Saving Behavior

The growing concern over energy consumption and its environmental impact has spurred extensive research into actual energy-saving behavior. The literature reveals that energy-saving behavior is not a simple or one-dimensional concept. It encompasses a wide range of actions to reduce energy use, from habitual practices such as turning off lights to more substantial investments in energy-efficient appliances. The motivations behind such behavior are multifaceted, encompassing both self-interested economic concerns (egoism) and broader environmental or social responsibility (altruism) (Duong, 2022; Fatoki, 2023).

The factors influencing energy-saving behavior are complex and varied. Psychological factors, such as attitudes, beliefs, norms, and perceived control, play a significant role in shaping intentions and actions (Ajzen, 1991). Demographic factors, including age, gender, education, and income, can also impact energy-saving behaviors. Additionally, contextual factors such as the physical environment, social context, economic incentives, and policies can create barriers or opportunities for energy conservation (J. Hong et al., 2019; Kotsopoulos et al., 2023; B. Wang et al., 2018).

Research has also focused on understanding energy-saving behavior in specific groups and contexts, such as college students, farmers, and workplace settings (Dixon et al., 2015; Du & Pan, 2021a; Kurokawa et al., 2023; Li et al., 2023; Tverskoi et al., 2021; Xie et al., 2021). These studies reveal different individuals’ diverse motivations and constraints and the need for tailored interventions to promote energy conservation effectively. Despite growing interest, prior studies often examine isolated predictors of energy-saving behaviors, lacking an integrated perspective. This study addresses this gap by combining TPB and NAM to offer a comprehensive framework for understanding the psychological mechanisms behind guests’ energy-saving intentions and behaviors in the hotel context.

2.2. Theory of Planned Behavior (TPB) and Energy-Saving Behavior

The Theory of Planned Behavior (TPB), formulated by Ajzen (1991), is a widely used theoretical framework for understanding pro-environmental behaviors, particularly in energy-saving actions within hotels. The TPB posits that behavioral intention is the primary predictor of actual behavior and is influenced by three key constructs: attitude, subjective norms, and perceived behavioral control (PBC). These factors collectively shape an individual’s readiness to engage in specific behaviors, such as conserving energy (Ajzen, 1991). Subjective norms capture perceived social expectations or pressures from others that may influence the individual’s choices (Ajzen, 1980). Perceived behavioral control refers to a person’s perceived ease or difficulty in performing the behavior, reflecting their confidence and control over the action (Ajzen, 1991). In addition to influencing intention, PBC can directly impact actual behavior (Budovska et al., 2020; Du & Pan, 2021b; Fatoki, 2021).

The TPB has been extensively utilized to predict various pro-environmental behaviors, such as recycling, using public transportation, consuming green products, and conserving energy (Chen, 2016; Han & Yoon, 2015; Shin et al., 2018). In pro-environmental behaviors, individuals with a positive attitude toward energy-saving practices are more likely to adopt such behaviors (Schwartz, 1977). Numerous studies have employed TPB in the hotel sector to assess guests’ and employees’ pro-environmental intentions and actions. For example, C.-P. Wang et al. (2023) reported that attitude, subjective norms, and PBC significantly influence guests’ intentions to visit green hotels. Meanwhile, Chia and Xiong (2023) and Limbu et al. (2023) found similar effects on guests’ decisions to order organic food during their stays.

However, the influence of these TPB constructs is not always consistent across studies. For instance, Yeh et al. (2021) observed no significant correlation between subjective norms and green hotel consumption intentions, suggesting that social pressures may not always drive behavior in the same way across different contexts. Other studies have also noted non-significant relationships between TPB variables and PEBs, such as those by Hameed et al. (2019), who found that attitude toward green products did not significantly predict eco-friendly behavior. Similarly, Ateş (2020) and X. Liu et al. (2020) reported weak links between subjective norms and various pro-sustainability actions, including household energy-saving behaviors.

Energy-saving intention reflects an individual’s motivation and commitment to act, serving as a direct antecedent of behavior. According to TPB, intention is the most immediate predictor of actual behavior. Therefore, stronger energy-saving intentions are expected to translate into concrete actions, bridging the gap between awareness and behavioral execution. Drawing upon the TPB framework and prior empirical findings, this study explores the psychological factors influencing hotel guests’ energy-saving intentions and behaviors. The research proposes the following hypotheses:

H1. 

Attitude (AT) has a positive influence on energy-saving intention (ESI).

H2. 

Subjective norms (SNs) have a positive influence on energy-saving intention (ESI).

H3. 

Perceived behavioral control (PBC) has a positive influence on energy-saving intention (ESI).

H4. 

Perceived behavioral control (PBC) has a positive influence on energy-saving behavior (ESB).

H5. 

Behavior intention (ESI) has a positive influence on energy-saving behavior (ESB).

These hypotheses aim to reinforce the applicability of TPB in the lodging industry context, providing valuable insights into the psychological drivers behind guests’ energy-saving actions.

2.3. Norm Activation Model (NAM) and Energy-Saving Behavior

While the TPB emphasizes the role of rational cognition, suggesting that personal motives drive behavioral intention, the norm activation model (NAM) highlights moral motives as the primary determinant of an individual’s willingness to engage in specific behaviors (B. Wang et al., 2018). The NAM posits that an individual’s behavior is driven by a sense of responsibility, awareness of consequences, and personal norms (Y. Hong & Furnell, 2021). Specifically, personal norms, shaped by one’s level of awareness of consequences and ascription of responsibility, are the key determinants of behavior. Researchers who recognize the TPB’s limitations in overlooking non-rational, non-cognitive, emotional, and altruistic motivations (B. Wang et al., 2018) have integrated the TPB and NAM to enhance the understanding of pro-environmental behaviors (Goh et al., 2022). The literature demonstrates the effectiveness of this integrated approach in exploring predictors of energy-saving behaviors and other pro-environmental and pro-social behaviors (Schwartz, 1977; Si et al., 2021).

The two core components of the NAM, awareness of consequences and ascription of responsibility, can be viewed as internal stimuli, as the model is grounded in activating an individual’s moral and ethical dimensions (Schwartz, 1977). Awareness of consequences refers to an individual recognizing the negative impacts of not engaging in pro-social behaviors on others or the environment. Ascription of responsibility signifies a feeling of personal accountability for these negative consequences (Rezaei et al., 2019; Ru et al., 2018).

Rezaei et al. (2019) contend that when individuals are aware of the negative consequences of their inaction and feel personally responsible, they experience a moral obligation to act, referred to as personal norms. In energy conservation, individuals with a heightened awareness of the negative consequences of not saving energy and a greater sense of personal responsibility are more likely to feel a moral obligation to engage in energy-saving behaviors.

The norm activation model (NAM) further supports this, suggesting that personal norms, reflecting an individual’s moral obligation, are critical drivers of pro-environmental actions (Müller-Pérez et al., 2022). Empirical studies in the lodging industry have corroborated this link, demonstrating the positive impact of personal norms on intentions related to water conservation, waste reduction, and towel reuse (Han et al., 2020; Han & Hyun, 2018). The convergence of theoretical models and empirical evidence suggests that the hypothesis is well-founded and likely to be confirmed in the context of hotel energy-saving behavior.

While intention and behavior might not always perfectly align, it is widely accepted that intention serves as a key predictor of behavior in general (Yu et al., 2021) and pro-environmental behaviors specifically (Ajzen, 2020; Chakraborty et al., 2022). Nevertheless, within the specific realm of energy conservation, the link between energy-saving intention and actual behavior remains somewhat unclear. Some studies have revealed a positive influence of intention on energy-saving actions (Sultan et al., 2021), while others have reported a negligible relationship (Hamouri, 2023). This discrepancy underscores the necessity for additional research to illuminate this connection. Consequently, the present study posits that energy-saving intention positively affects energy-saving behavior.

Based on these theoretical underpinnings, the following hypotheses were proposed:

H6. 

Ascription of responsibility (AR) positively influences personal norms (PNs).

H7. 

Awareness of consequences (AC) has a positive influence on personal norms (PNs).

H8. 

Personal norms (PNs) have a positive influence on energy-saving behavior intention (ESI).

H9. 

Personal norms (PNs) have a positive influence on energy-saving behavior (ESB).

3. Methodology

3.1. Research Model and Measurements

We adapted TPB variables and NAM variables to develop the research model and proposed nine hypotheses to test the influence of six independent factors on energy-saving intention and energy-saving behavior. Figure 1 illustrates our hypotheses.

In this study, the measurement scale of energy-saving behavior (ESB) and energy-saving intention (ESI) were adapted from the studies of X. Liu et al. (2021). The scales of attitude (3 items), subjective norms (4 items), and perceived behavioral control (3 items) were modified from the studies of Du and Pan (2021b) and Yeh et al. (2021). Three constructs adapted from the NAM are ascription of responsibility (4 items), awareness of consequences (4 items), and personal norms (4 items) were adopted and adapted from B. Wang et al. (2018) and Xuan et al. (2023).

3.2. Sampling and Data Collection

A self-administered survey was conducted in Hanoi and Quang Ninh, where there is a great concentration of firms in the Vietnamese hospitality industry. These are two of the three leading provinces/cities in tourism in Vietnam (in terms of the number of tourists in 2024). A mixture of convenience and snowball sampling methods was employed in this study. Potential respondents of our study were customers of hotels located in Hanoi and Quang Ninh province. Firstly, we selected the hotels from the list registered with the Vietnam National Authority of Tourism. We sent an introductory email to all hotels in Hanoi and Quang Ninh, followed by phone calls and personal meetings. We asked for their consent to participate in our study and to approach their customers. Furthermore, we also distributed our questionnaire through several tourism forums and networks to attract more potential respondents. Participants were asked whether they had stayed in a hotel in the past 3 months. If they answered “no,” the survey ended. Those who answered “yes” continued to answer questions with a focus on the questions related to constructs in the research model.

After four months, we received 271 responses, of which 253 valid ones were included for further analysis. Concerning the sample characteristics, 159 female respondents account for 62.8%; the rest are men. The number of people below the age of 30 is 65, comprising 25.7%; the number of people from 30 to 45 years old is 147, comprising 58.1%; and the rest are aged 46 and over. Most visitors hold university degrees, namely 158 people (62.5%), 59 people (23.3%) hold postgraduate degrees, and the rest hold other degrees. Ninety-six people (37.9%) earned below 10,000,000 VND in a month; ninety-five people (37.5%) reported from 10,000,000 VND to 20,000,000 VND monthly income, and sixty-two people (24.5%) earned over 20,000,000 VND per month. Of the 253 respondents, 23 stayed in 5-star hotels (9.1%), 90 respondents stayed in 4-star hotels (35.6%), 70 respondents stayed in 3-star hotels (27.7%), and the remaining 70 respondents stayed in 1–2-star hotels and unrated hotels (27.7%). The sociodemographic information profile of respondents is representative.

3.3. Data Analysis Strategy

The reliability and validity of the measurements were examined using SmartPLS 4.0 software. Cronbach’s alpha was the criterion for the reliability test. The validity of the measures was evaluated based on the variance composite reliability (CR) and average variance extracted (AVE). The least squares structural model analysis (PLS-SEM) was employed to test the hypotheses. Tests were evaluated at the 5% significance level. The bootstrap analysis, with a sample of 5000, helped evaluate relationships in the research model.

4. Findings and Discussions

4.1. Preliminary Results

The reliability test was conducted, and all items met the cut-off value of the outer loading value. Thus, 28 items of the measurement instruments were used for further analysis. Regarding the reliability of the measurements, all factors have a Cronbach’s alpha value higher than 0.8. This result confirmed the convergence of all factors in the research model.

Table 1. Measurement reliability and validity testing results.

Construct	Code	Outer Loading	Cronbach’s Alpha	Composite Reliability (rho_a)	Average Variance Extracted (AVE)
Awareness of consequences (AC)	AC1	0.952	0.962	0.963	0.898
	AC2	0.960
	AC3	0.932
	AC4	0.946
Ascription of Responsibility (AR)	AR1	0.932	0.936	0.940	0.840
	AR2	0.957
	AR3	0.931
	AR4	0.840
Attitude (AT)	AT1	0.919	0.891	0.893	0.821
	AT2	0.916
	AT3	0.883
Energy-saving Behavior (ESB)	ESB1	0.929	0.930	0.930	0.827
	ESB2	0.901
	ESB3	0.919
	ESB4	0.887
Energy-saving Intention (ESI)	ESI1	0.873	0.839	0.841	0.757
	ESI2	0.848
	ESI3	0.888
Perceived Behavior Control (PBC)	PBC1	0.766	0.829	0.865	0.744
	PBC2	0.913
	PBC3	0.901
Personal Norm (PNs)	PN1	0.875	0.915	0.918	0.796
	PN2	0.868
	PN3	0.904
	PN4	0.922
Subjective Norms (SNs)	SN1	0.885	0.925	0.926	0.817
	SN2	0.924
	SN3	0.899
	SN4	0.908

presents the details.

The discriminant validity was checked using the Fornell–Larcker test and HTMT criterion results. For each construct, we assessed the discriminant validity by comparing the square root of each AVE in the diagonal with the correlation coefficients (off-diagonal) in the relevant rows and columns. As shown in

Table 2. Discriminant validity using the Fornell–Larcker criterion.

	AC	AR	AT	ESB	ESI	PBC	PN	SN
AC	0.948
AR	0.816	0.916
AT	0.701	0.616	0.906
ESB	0.555	0.568	0.646	0.909
ESI	0.656	0.669	0.709	0.782	0.870
PBC	0.660	0.675	0.564	0.631	0.627	0.863
PN	0.572	0.653	0.576	0.629	0.659	0.492	0.892
SN	0.675	0.600	0.748	0.647	0.721	0.523	0.610	0.904

, the square root of the AVE for all eight constructs (the values in bold) ranges from 0.870 to 0.948, and it is higher than any of the correlation coefficients in the vertical and horizontal related cells. Overall, the discriminant validity between the eight constructs in this study was supported. In addition, as shown in

Table 3. Discriminant validity using the HTMT ratio.

	AC	AR	AT	ESB	ESI	PBC	PN	SN
AC
AR	0.850
AT	0.759	0.674
ESB	0.586	0.610	0.710
ESI	0.723	0.751	0.814	0.805
PBC	0.720	0.759	0.639	0.708	0.733
PN	0.611	0.707	0.635	0.676	0.745	0.560
SN	0.717	0.642	0.823	0.696	0.816	0.572	0.664

, the HTMT values of all constructs were below the threshold value of 0.85, so the discriminant validity of measurement scales is acceptable in this study (Henseler et al., 2015).

Another criterion utilized in this study was R².

Table 4. R-square results.

Construct	R-Square	R-Square Adjusted
ESI	0.670	0.665
PN	0.431	0.427
ESB	0.660	0.656

shows that the R² value of ESI was 0.665, which means that AT, SN, and PBC explained 66.5% of the variance of ESI. Meanwhile, the R² value of PN was 0.427, showing that AR and AC explained 42.7% of the variance of PN. Finally, all factors in the structural model explained 65.6% of the variance of ESB, as the R² value of ESB was 0.656. This result means that the coefficient determination was confirmed as all R² values of endogenous variables were above 0.3 (Hair & Alamer, 2022). The structural model achieved moderate fitness for further analysis (see Table 4).

4.2. Hypothesis Testing Results

We conducted the PLS-SEM analysis to test the hypotheses in this study. The results are presented in

Table 5. Results of testing direct effects.

Hypothesis	Relationship	Original Sample (O)	Standard Deviation (STDEV)	T Statistics (|O/STDEV|)	p-Value	Result
H1	AT ⟶ ESI	0.227	0.077	2.959	0.003	Supported
H2	SN ⟶ ESI	0.281	0.094	2.979	0.003	Supported
H3	PBC ⟶ ESI	0.233	0.064	3.666	0.000	Supported
H4	PBC ⟶ ESB	0.210	0.078	2.696	0.007	Supported
H5	ESI ⟶ ESB	0.536	0.093	5.766	0.000	Supported
H6	AR ⟶ PN	0.559	0.113	4.965	0.000	Supported
H7	AC ⟶ PN	0.116	0.109	1.061	0.289	Rejected
H8	PN ⟶ ESI	0.242	0.095	2.539	0.011	Supported
H9	PN ⟶ ESB	0.172	0.088	1.956	0.051	Rejected

below.

Table 5 illustrates that seven out of nine proposed hypotheses were supported with p-values lower than 0.05. Two hypotheses, H7 and H9, were rejected.

4.3. Discussions

The present study supports the integrated model of TPB and NAM to explain the energy-saving behavior of hotel guests, as most of the proposed hypotheses were accepted. It is recognized that the majority of the proposed relationships are significant, whereas two hypotheses (H7 and H9) were not supported.

Hypothesis H1 was supported, indicating a positive relationship between AT and ESI (β1 = 0.227) with a significant t-statistic (2.959) and a p-value of 0.003. Meanwhile, H2 and H3 are similarly supported by comparable statistical strength, underscoring the impact of SN and PBC on ESI. Furthermore, hypothesis H4 indicates that perceived behavioral control has a significant effect on energy-saving behavior (ESB), evidenced by β4 = 0.210 and a p-value of 0.007. Our findings are similar to the studies of Chen (2016) in Taiwan and X. Liu et al. (2021) in China when examining individual and household energy-saving behaviors, respectively. It is also noted that among the three factors of TPB, SN has the strongest impact on ESI and also a significant direct impact on ESB. This finding is attributed to the nation’s robust collectivist culture. In Vietnamese society, individuals often adhere to social norms and the conduct of their peers, particularly family, friends, and authority institutions. Guests are more inclined to adopt energy-saving behaviors, such as turning off lights and air conditioning upon exiting a room, when they feel that others endorse or anticipate such actions. Moreover, hotels are progressively advocating sustainability efforts, strengthening the belief that energy conservation constitutes a social norm. Observable indicators, including staff motivation and posters urging patrons to conserve energy, enhance this effect. Peer influence, such as witnessing fellow visitors participating in environmentally sustainable practices, also contributes significantly. Consequently, subjective norms generate social pressure and a sense of obligation, prompting guests to conform their conduct to environmental standards, thereby enhancing energy-saving behavior.

The most robust relationship identified is between ESI and ESB, characterized by a coefficient value of 0.536 and a highly significant p-value of 0.000, underscoring the essential influence of energy-saving intention on energy-saving behavior. This finding is in line with the results of several studies on pro-environmental behaviors in both Western and Eastern countries, such as the studies by Budovska et al. (2020) conducted in Norway, McCarthy(2024) conducted in Australia, B. Wang et al. (2018), Q.-C. Wang et al. (2023) conducted in China, and Xuan et al. (2023) conducted in Vietnam.

It is noteworthy that in this study, the analysis of personal norms (PNs) yields inconclusive findings. The relationship between ascription of responsibility (AR) and personal norms (PN) is robustly supported (β6 = 0.559, p-value = 0.000), indicating a positive influence of AR on PN. On the contrary, hypothesis H7 was rejected based on a high p-value of 0.289, indicating that awareness of consequences (AC) does not significantly affect personal norms. In the context of hotel visitors in Vietnam, AC may not substantially affect personal norms (PNs) for various reasons. Initially, residing in a hotel is perceived as a transient experience in which guests emphasize comfort over accountability. They may perceive that energy expenses and sustainability initiatives fall under the hotel’s purview rather than their own obligations. Secondly, cultural and habitual influences are significant. Numerous Vietnamese consumers may lack robust pre-existing personal values concerning energy conservation in commercial environments. The absence of observable repercussions or prompt feedback regarding energy consumption may diminish the sense of moral responsibility. Although guests may recognize environmental implications, this awareness does not automatically convert into ingrained personal norms, as their brief stay reduces the perceived significance of their activities within the wider sustainability initiative. Our findings are contrary to the study by Xuan et al. (2023), who investigated the ESI and ESB of Vietnamese people at home.

In addition, hypothesis H8 is significant (β8 = 0.242, p-value = 0.011), demonstrating that PN positively influences ESI. However, hypothesis H9 is marginally insignificant (p-value = 0.051), indicating a weak or non-significant effect of PN on ESB. The findings underscore the significance of energy-saving intention in forecasting energy-saving behavior while also elucidating the complex roles of personal norms. This finding was supported by several studies such as X. Liu et al. (2021), B. Wang et al. (2018), Q.-C. Wang et al. (2023), McCarthy (2024), Kotsopoulos et al. (2023).

5. Implications and Limitations

5.1. Theoretical Implications

In terms of theory, this study provides an integrative approach to revisit the energy-saving behavior of hotel guests. We merged the TPB and NAM in our investigation and confirmed that this integrative model is useful in explaining the energy-saving intention and behavior. In TPB, we adopted three main factors, including attitude, subjective norms, and perceived behavioral control. In the NAM, we included both ascription of responsibility and awareness of consequences. This combined research model is confirmed as offering a better explanation of the antecedents of ESB in the Vietnamese context when the simultaneous impact of the TPB and NAM variables was tested. Our empirical data revealed that the predictive ability of this model is quite good, with an R² of over 65%, indicating the contribution of external and internal stimuli in explaining the energy-saving behavior.

Additionally, our study contributes to the existing literature as there are limited studies in Vietnam on the topic of energy-saving behaviors in the lodging industry in particular and the hospitality industry in general. Previous studies in the Vietnamese context mainly addressed the energy-saving behaviors of individuals at home or in their workplace. Thus, our study pioneered exploring the ESB when they use lodging services.

5.2. Practical Implications

Our research contributes several practical implications with focused interventions for industry stakeholders. Hotels should prioritize strategies to enhance positive attitudes toward conservation, leverage social influence mechanisms, and increase guests’ perceived control over energy-saving actions. They must also create clear pathways to translate guests’ good intentions into actual energy-saving behaviors during their stay. Importantly, emphasizing personal responsibility rather than merely raising awareness of consequences would be more effective in activating personal norms that influence intentions, though interestingly, personal norms did not directly affect behaviors.

Hotels can translate these findings into practice by installing user-friendly energy management systems that enhance perceived control while making conservation behaviors intuitive. Actionable steps for hotels can be implemented, such as redesigning guest communication materials to highlight the positive impacts of energy conservation, developing in-room displays showing real-time energy usage compared to hotel averages, and installing intuitive smart room controls, smart key systems, and smart lighting that make energy-saving actions effortless. As the study shows, guests’ attitudes toward saving energy can be positively influenced, as the NAM emphasizes the role of personal norms in driving pro-environmental behavior. Thus, hotels should highlight their green practices in ads, social media, and websites. Green practices can become a selling point that attracts environmentally conscious guests and generates positive reviews. The hotel’s marketing and communications team should develop messaging that frames energy conservation as a shared responsibility, highlighting how each guest’s actions contribute to the hotel’s overall sustainability efforts and the well-being of the local community. This messaging should be integrated into in-room signage, welcome materials, and digital communications.

For broader implementation, policymakers and hotel associations should create supportive frameworks that encourage energy-efficient hospitality practices, including tax incentives for hotels that invest in conservation technologies and subsidies for energy-saving renovations. Additionally, government educational campaigns should emphasize personal responsibility in energy conservation while traveling. Establishing a standardized eco-certification program for Vietnamese hotels would give environmentally conscious travelers more explicit choices while creating market incentives for properties to improve their energy performance. Our findings also suggest creating standardized training modules for hotel staff, particularly front desk and housekeeping, on how to effectively communicate the importance of energy conservation to guests, demonstrate easy-to-use energy-saving technologies, and address guest questions or concerns about sustainability.

5.3. Limitations

There are several limitations of our study. First, snowball and convenience sampling can both introduce bias. Our survey polled hotel guests who visited Hanoi and Quang Ninh, two populated areas with tourists. Although the sample size is adequate to explain the ESB of hotel guests in these two chosen areas, the narrow scope of geographic location might limit the generalization of the study results. Thus, future research should increase the sample and employ different sampling approaches to gain more insights into ESB in the hospitality industry. Second, this study did not consider the impact of sociodemographic factors intervening in the impact of TPB variables and NAM variables on ESI and ESB. As a result, more research is needed to discover how sociodemographic factors might explain ESI and ESB. Future studies may also investigate contextual elements, such as cultural effects and organizational policies, to expand the model further. Third, we employed the self-reported survey method. Consequently, the actual behavior of ESB might not be captured in this study. We suggest that future research should have in-depth group interviews to gain more insights into energy-saving behavior.

6. Conclusions

This study investigated the impact of the theory of planned behavior (TPB) and the norm activation model (NAM) on energy-saving intention and behavior within the Vietnamese lodging industry. The results validate that both theories elucidate energy-saving behavior, with the TPB underscoring logical decision-making processes and the NAM accentuating moral requirements. Attitudes, subjective norms, and perceived behavioral control from the TPB greatly influence ESI and ESB, whereas AR and PN from the NAM are pivotal in creating pro-environmental action.

The amalgamation of the TPB and the NAM offers a more thorough comprehension of energy-saving behavior by connecting logical and normative factors. The findings indicate that improving environmental awareness, augmenting perceived control over energy saving, and cultivating moral responsibility might encourage sustainable lodging industry practices. Hotel owners should use initiatives, including training programs, incentive mechanisms, and informative campaigns, to strengthen rational and ethical energy conservation motives. Hotels may employ signage and in-room digital prompts to motivate customers to reuse towels, deactivate lights, and modify thermostats. Intelligent energy systems that adapt to room occupancy can strengthen these behaviors.

In addition, policymakers can facilitate these endeavors via rules and public awareness campaigns. They ought to encourage hotels to adopt green certifications and mandate transparency in energy use disclosures. Educational initiatives that integrate sustainability with visitor happiness enhance compliance motivation. Collectively, these strategies foster a conservation culture that enhances environmental sustainability and diminishes operational expenses while maintaining visitor comfort.