1. Introduction and background
Sustainable product design has gained growing attention as a critical instrument to address environmental challenges and promote responsible production and consumption patterns (Reference Ghazali, Abdul-Rashid, Dawal, Irianto, Herawan, Ho, Abdullah, Rasib and PadzilGhazali et al., 2023). However, the transition toward sustainable product design continues to face significant perceptual barriers. Although users increasingly express pro-environmental intentions, sustainable products are often judged as less effective than conventional ones (Reference Gong, Wang, Peverelli and SuoGong et al., 2022; Reference Skard, Jørgensen and PedersenSkard et al., 2021). This perceived inferiority has led to a growing body of literature on the adoption of sustainable products, particularly on the perceived trade-off between sustainability and other design attributes.
Previous studies have explored green decision-making through questionnaires, surveys, and scenario-based experiments (e.g., Reference Luchs, Naylor, Irwin and RaghunathanLuchs et al., 2010; Reference Luchs and KumarLuchs & Kumar, 2017; Reference Suh and YooSuh & Yoo, 2024). While these studies often use general indices of product sustainability, most have focused on identifying product- and user-related factors that explain (non-)preference for sustainable products (Reference Maccioni, Borgianni and BassoMaccioni et al., 2019). However, users’ evaluations depend not only on general factors (such as aesthetics) but also on how users interpret the design attributes associated with sustainability (Reference Luchs, Brower and ChitturiLuchs et al., 2012; Reference She and MacDonaldShe & MacDonald, 2018). Consequently, the success of sustainable products depends not only on their actual environmental performance but also on how effectively their design communicates this intent (Reference Diego-Mas, Poveda-Bautista and Alcaide-MarzalDiego-Mas et al., 2016; Reference El Dehaibi and MacDonaldEl Dehaibi & MacDonald, 2022). Research on sustainable product design has revealed a persistent mismatch between design intention and user interpretation (Reference Berni and BorgianniBerni & Borgianni, 2025; Reference Crilly, Good, Matravers and ClarksonCrilly et al., 2008). Users rarely assess a product’s sustainability by analyzing its environmental impact; rather, they rely on perceptual cues embedded in the product’s form, materials, or structure (Reference Du and MacDonaldDu & MacDonald, 2018; Reference El Dehaibi and MacDonaldEl Dehaibi & MacDonald, 2022). For example, Reference She and MacDonaldShe and MacDonald (2018) demonstrated that a flip-cover to retain heat and an energy-saving button on a toaster can trigger sustainability-related thoughts. In this context, examining how people perceive the role of sustainability-related attributes within the product’s overall design becomes particularly relevant. The literature highlights two key factors that may influence how users perceive sustainability and assess the performance of sustainable products (Reference Sierra-Fontalvo, Berni and BorgianniSierra-Fontalvo et al., 2026):
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• The hierarchy of product attributes due to their centrality or peripherality
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• The presence/absence of implicit sustainability cues.
The former concern how users evaluate the centrality of sustainable attributes in relation to the overall performance of a product (Reference Gershoff and FrelsGershoff & Frels, 2015; Reference Skard, Jørgensen and PedersenSkard et al., 2021). Attribute centrality refers to the degree to which an attribute is perceived as essential to the identity of a concept or object, distinguishing between central and peripheral attributes (Reference NolesNoles, 2019; Reference Sloman, Love and AhnSloman et al., 1998). Central attributes are those considered indispensable for defining what a product is, in a way that altering them would change the product’s conceptual identity. In contrast, peripheral attributes can be modified without affecting this identity (Reference Sloman, Love and AhnSloman et al., 1998). For example, Reference Gershoff and FrelsGershoff and Frels (2015) found that a laptop was perceived as more sustainable when its CPU motherboard (a central component) was made from recycled materials, compared to when only its sound card (a peripheral component) was. However, there is a need for further research into how users interpret the centrality of sustainable design attributes, particularly when these attributes serve as implicit sustainability cues (Reference Luchs, Brower and ChitturiLuchs et al., 2012; Reference She and MacDonaldShe & MacDonald, 2018).
With implicit sustainability cues we refer to those sustainability cues that are not immediately obvious or explicitly stated; rather, they consist of design attributes that signal environmental benefits in ways that are subtly perceived and interpreted by users (Reference Diego-Mas, Poveda-Bautista and Alcaide-MarzalDiego-Mas et al., 2016; Reference She and MacDonaldShe & MacDonald, 2018). Therefore, understanding how users perceive and evaluate implicit sustainability cues can guide designers to identify those design attributes and eco-design strategies that communicate sustainability intentions more effectively (Reference Luchs, Brower and ChitturiLuchs et al., 2012; Reference She and MacDonaldShe & MacDonald, 2018). In this sense, eco-design strategies are not only design approaches that integrate environmental considerations into product development (Reference Maccioni, Borgianni and PigossoMaccioni et al., 2021), but can also trigger sustainability consideration. However, since users’ recognition of eco-design strategies is influenced by their personal awareness and subjectivity, these strategies may not always be clearly identifiable and can function as implicit sustainability cues themselves.
The uncertainty surrounding implicit sustainability cues, coupled with ambiguity over which design attributes are considered central or peripheral to a product, often makes it difficult for users to recognize and evaluate the trade-offs between sustainable and conventional products. As a result, users may become confused about the designer’s intentions regarding sustainability, which in turn can hinder their willingness to adopt sustainable products. A better understanding of these aspects is essential, especially because few studies have explored how the interplay between attribute centrality and implicit sustainability cues affects perceptions of sustainable design.
To address the above gap, this study investigates how users perceive and interpret both the centrality and sustainability of design attributes associated with three eco-design strategies: modular design, design for disassembly, and energy efficiency. Specifically, the research questions of this study are:
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• RQ1. How do users perceive the centrality of sustainability-related design attributes in everyday products?
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• RQ1.1. Does the perceived centrality of a sustainable attribute differ significantly depending on the eco-design strategy?
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• RQ2. How do users evaluate the environmental sustainability of products with eco-design strategies compared to their conventional counterparts?
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• RQ3. What is the relationship between the perceived centrality of a design attribute and the perceived environmental sustainability of the product?
2. Methodology
2.1. Research design and stimulus selection
This study employed an online survey to examine how users perceive the centrality and sustainability of nine design attributes derived from three eco-design strategies: modular design, design for disassembly, and energy efficiency. These strategies were selected to represent different approaches to implementing sustainability in product design. Modular design and design for disassembly are commonly described as structural strategies that facilitate repair, replacement, and product lifetime extension, whereas energy efficiency represents a widely adopted strategy that generates environmental benefits through improved product operation (Reference Borgianni, Maccioni, Pigosso, Ball, Huaccho Huatuco, Howlett and SetchiBorgianni et al., 2019; Reference VezzoliVezzoli, 2018).
Participants evaluated a set of nine products, each representing one of three investigated eco-design strategies. Products were selected based on the following criteria: (1) they are familiar, everyday products to minimize the influence of novelty or lack of prior knowledge; (2) each product clearly embodied a single eco-design attribute associated with one of the investigated strategies; (3) the attribute could be described and visually represented in a neutral manner, without explicit sustainability framing. Each product was presented with an evocative picture (using unbranded images) and a short-neutral description of the key design attribute (e.g., “This desktop PC tower is designed with replaceable internal components. Key components, such as memory, storage, and the graphics card, can easily be swapped out.”). The images and descriptions were formatted uniformly to reduce visual or linguistic confusion. Product descriptions were also strictly focused on functional characteristics, avoiding explicit environmental framing. Prior to data collection, the survey questionnaire and visual stimuli were pilot-tested involving two experts in sustainability and product development. The pilot test aimed to assess whether:
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• the asked questions were clear and easy to answer
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• the stimuli and the descriptions were not biased toward a sustainability interpretation
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• the duration of the survey was not excessive, namely below 30 minutes.
Based on the feedback received, the formulation of some questions was modified, as well as the visual representations of some products. The second version of the survey was then re-evaluated by the same experts and positively assessed, supporting the content validity of the final instrument. Table 1 presents the products used for each eco-design strategy and their sustainable attribute.
Overview of the products and their corresponding sustainable attributes across the three eco-design strategies
2.2. Survey structure
The survey consisted of three main sections: (1) product feature evaluation, (2) overall product impressions, and (3) demographic questions. The structure of each section is described below.
Product feature evaluation: The first part of the survey aimed to explore the perceived centrality of each sustainable attribute. Following prior research on conceptual centrality, the methodology of Reference Sloman, Love and AhnSloman et al. (1998) was adopted. Participants were asked three questions that capture distinct aspects of how the absence of a given attribute affects the mental representation of the product: surprise, ease of imagining, and goodness of example. The formulation of the corresponding questions was slightly changed following the pilot testers’ indications. Figure 1 presents an example of the three questions. The survey foresaw that products had to be evaluated one at a time using a seven-point Likert scale. An additional question about familiarity with the product was asked to contextualize centrality judgments.
Example of a product and the corresponding evaluation template related to the first part of the survey
Overall product impression: This section focused on two aspects: (1) perceived sustainability and (2) identification of the eco-design strategy. First, participants rated how sustainable each product appeared relative to its counterpart without the highlighted attribute (e.g., a desktop PC tower with replaceable vs. fixed internal components). Then, they were asked to select the main design strategy they associated with each product from a list (e.g., designed for adaptation and upgrades, designed for energy efficiency, designed for maintenance and repair, designed for material reduction, and I’m not sure/I don’t know). It is worth noting that the list also included eco-design strategies that were not directly associated with any specific product. Indeed, a pilot tester suggested the inclusion of an additional strategy that could also be associated with one of the evaluated products. This adjustment was made to ensure that the identification task accurately reflected participants’ interpretations of the products and their underlying design strategies.
Demographic section: Finally, participants were asked about their age group, highest level of education, primary field of work or study, and familiarity with concepts such as sustainable design, eco-design, and the circular economy.
2.3. Administration of the survey
The survey was administered online using SurveyMonkey. Participants accessed the survey via a public link distributed by email. Participation was voluntary and the data was anonymized by removing the option of collecting the IP address of respondents. On the survey’s landing page, participants were provided with instructions and a hyperlink to the informed consent document. This document explained the purpose of the study and how their data would be managed before they began the survey.
The survey was conducted in English, and the average completion time was approximately 22 minutes. A copy of the survey can be accessed at (https://eu.surveymonkey.com/r/52RFTTB). This link is provided for reference only; any new responses submitted through this form will not be collected.
3. Results and discussions
A total of 49 responses were collected, out of which 42 were valid and included in the analysis. Participants were predominantly adults between 25 and 54 years old, with the largest proportion in the 25-34 age group (42.9%). The sample had a high level of education, with 81.75% holding postgraduate degrees. In terms of academic and professional background, most participants came from IT, Engineering, or Technology fields (71.3%), followed by Arts, Design, and Architecture (16.7%). Regarding familiarity with sustainability-related concepts, most participants reported moderate to high familiarity, with 40% being “very familiar” and 26% “extremely familiar”. The following sections present the results for each research question.
3.1. RQ1 – centrality of sustainability-related design attributes
To assess the perceived centrality (RQ1), three conceptual centrality measures adapted from Reference Sloman, Love and AhnSloman et al. (1998) namely surprise, ease of imaging, and goodness of example were used as ordered variables (ranging from 1 to 7). In all three measures, lower scores indicated that the attribute was perceived as more peripheral, whereas higher scores indicated that it was perceived as more central to the product’s identity.
An initial Spearman correlation analysis showed strong, positive, and statistically significant associations among the three centrality measures (rho values ranging from 0.618 to 0.718, p < .001). These results indicate that all three questions consistently captured the concept of product centrality. For subsequent analyses regarding product attribute centrality, the variable related to participants’ sense of surprise was conveniently chosen since it demonstrated the highest inter-variable correlation with the other two variables, and was therefore considered the most representative single indicator of the construct in this specific context. Figure 2 presents the results of the centrality according to this variable for all the products examined in the survey. In general, the results showed mixed perceptions of centrality, reflecting uncertainty about whether the attribute is perceived as peripheral or central. In the case of the shelving system (stackable frame modules), washing machine (front-loading, horizontal-axis drum), and torch (hand-powered energy system), the attributes were consistently rated as peripheral. Conversely, the other products showed polarized perceptions. While some participants considered the design attribute central to product identity, a similar proportion perceived it as peripheral. For example, the attribute of “replaceable internal components” in a desktop PC tower received the same number of responses at both low (1 to 3) and high (5 to 7) centrality values, suggesting that there is no consensus on the extent to which this design attribute contributes to product identity. Other products followed this pattern with a slight tendency towards high centrality values.
Distribution of responses for the perceived centrality of sustainable design attributes across products
Then, to analyze whether perceived centrality differs according to the eco-design strategy (RQ1.1), responses were filtered to include only participants who correctly identified the design strategy of each product in line with Table 1. Table 2 presents the results of the surprise measure (hence interpreted as centrality) for all products. The overall pattern of perceived centrality remained consistent with the results presented in Figure 2. While the trend toward lower values in the shelving system suggests that modularity is perceived as a peripheral rather than a central attribute, the results for the desktop PC tower and power tool were more polarized. Similarly, for the energy-efficient products, the electric kettle showed centrality scores distributed across the scale (28% were not surprised and 21% were extremely surprised). However, the washing machine and the torch were predominantly rated as peripheral (46% and 90% were not surprised, respectively). Regarding design for disassembly, the blender and the bicycle also showed mixed perceptions with a tendency toward higher values (bicycle: 31% extremely surprised; blender: 27% extremely surprised). The camping tent showed a marked polarization of responses, but this is affected by the lower number of correct identifications of the implemented eco-design strategy. These results indicate that the correct identification of an eco-design strategy neither increases the perceived centrality of the attribute nor differentiates which strategy is perceived as more central.
Distribution of responses for the surprise measure across all products after filtering the dataset
Moreover, the varied responses also suggest that the extent to which participants perceived the design attribute as central or peripheral depends on their expectations and familiarity with “conventional” versions of the product (by the term “conventional” we mean equivalent versions of the product without the sustainable attribute). For example, in the case of the shelving system, the washing machine, and the torch, the conventional versions are highly familiar and standardized, making the sustainable attribute appear less essential to the product’s identity, thus peripheral. In contrast, for the other products, the sustainable attribute seemed to match participants’ expectations regarding what the product usually includes, but it is not necessarily perceived as central. This led to mixed perceptions: while some participants interpreted the attribute as integral to the product’s identity (thus central), others considered it a desirable attribute but not a defining attribute (thus peripheral). For example, since a desktop PC tower without replaceable internal components can still perform its core functions, some participants may have perceived the attribute as peripheral rather than central to the product’s identity.
It is important to note that the identification of eco-design strategies of the products was presented after the centrality-related questions. Additionally, participants were not asked to review their previous responses. Therefore, the stability observed in the results of RQ1 and RQ1.1 suggests that participants’ centrality judgments were based on their immediate mental representations of the product, rather than on reasoning about the sustainability intention underlying the attribute. In this sense, the results reinforce the idea that participants evaluate whether an attribute is central or peripheral based on the structural and functional expectations of the product.
3.2. RQ2 – environmental sustainability of products with eco-design strategies
After evaluating centrality, participants were asked to assess the sustainability of each product relative to a conventional alternative without the highlighted attribute. A qualitative analysis examined whether the attribute increased, decreased, or had no effect on perceived sustainability. Figure 3 summarizes participants’ evaluations of environmental sustainability across the products.
Overall, the presented products were seen as more environmentally sustainable than their counterparts. However, the intensity of this perception varied across products. For example, attributes such as replaceable internal components (desktop PC tower), hand-powered energy systems (torch), and removable components (bicycle) were associated with higher rates of perceived sustainability, with more than 80% of participants rating these products as more sustainable than their counterparts. In contrast, the attributes highlighted in the washing machine and the camping tent elicited weaker responses, with most participants remaining neutral, rating their sustainability as equal to that of the alternative version (74% and 62% respectively). It is worth noting that many participants (47.63% for the washing machine and 42.86% for the camping tent) were unable to identify the eco-design strategy for these two products. This suggests that when users cannot clearly associate an attribute with a sustainability purpose, the attribute fails to act as a sustainability cue.
The results also suggest that attributes that visibly communicate functional or user-involved sustainability, such as replaceable components or self-generated power, are evaluated as more sustainable than those perceived as technical or less evident (e.g., energy efficiency in washing machines). These reflections support the idea that users may fail to recognize technical sustainable attributes unless the environmental benefits are made salient. For example, although the automatic shut-off sensor on an electric kettle is a less visible sustainable attribute, most participants considered it highly sustainable, likely because of its straightforward link with energy saving, a concept that is both intuitive and widely understood by users.
These results may also reflect differences in how eco-design strategies manifest in product form. Strategies such as modularity or design for disassembly are directly observable and often require user interaction, making them easier to interpret as environmentally meaningful, probably because they align with well-known sustainable behaviors, such as repairability. In contrast, strategies such as energy efficiency, while valuable from an environmental perspective, remain largely “hidden” to users. These findings highlight the need for designers to make technical sustainable attributes more perceptually explicit, so that users can more easily associate them with environmental value.
Effect of eco-design attributes on perceived product sustainability
3.3. RQ3 – relationship between the perceived centrality and the perceived environmental sustainability of a product
To explore the relationship between the perceived centrality of the design attribute and the perceived environmental sustainability of the product, a Spearman correlation was performed. This analysis aimed to determine whether participants who perceived an attribute as more central to a product’s identity were also more likely to consider the product more environmentally sustainable. Drawing on previous studies (e.g., Reference Gershoff and FrelsGershoff & Frels, 2015; Reference Skard, Jørgensen and PedersenSkard et al., 2021), it was expected that central design attributes would enhance sustainability perceptions, whereas peripheral attributes would have a limited influence.
When considering all products together, the correlation was weak but statistically significant (rho=0.121, p=.018). This result indicates that participants who viewed an attribute as more central were only slightly more likely to perceive the product as more environmentally sustainable. Although significant, the low magnitude of the relationship suggests that perceived centrality alone has limited explanatory power in predicting sustainability judgments.
To better understand this phenomenon, a qualitative analysis of individual product results offers illustrative contrasts. For example, the torch with a hand-powered energy system was rated as more environmentally sustainable than its conventional counterpart (83% of participants rated this product as more sustainable); however, its “sustainable attribute” was perceived as peripheral to the product’s identity. Similarly, in the case of the desktop PC tower, participants’ evaluations of centrality were polarized, with 36% of participants rating the “replaceable internal components” as a peripheral attribute and another 36% as a central attribute. However, 90% of participants rated the product as more environmentally sustainable than its conventional counterpart with fixed internal components. These results indicate that participants can recognize the environmental value of an attribute even when they do not consider it an integral part of the main product design. In such cases, the perception of sustainability seems to derive from the functional meaning of the attribute (i.e., enabling repair and component replacement) rather than from its centrality.
Contrary to what Reference Gershoff and FrelsGershoff and Frels (2015) suggested, these results imply that the perception of environmental sustainability is not necessarily driven by attribute centrality, but rather by the salience and interpretability of the environmental benefit. Participants may evaluate sustainability based on their prior knowledge or assumptions about what makes a product sustainable. Therefore, the relationship between attribute centrality and perceived sustainability may vary depending on the degree to which the environmental benefit is self-evident. For example, functional or user-involved attributes can trigger strong sustainability perceptions even when perceived as peripheral, while technical attributes may elicit similar responses when their benefits align with familiar sustainability concepts, such as energy saving.
4. Conclusions
This study has explored how users perceive and interpret the centrality and sustainability of design attributes associated with three eco-design strategies: modular design, design for disassembly, and energy efficiency. By addressing the research questions listed at the end of Section 1, this study aimed to understand not only whether users recognize eco-design strategies as integral to a product’s identity but also whether such recognition translates into higher sustainability evaluations.
The findings related to RQ1 and RQ1.1 indicate that sustainable design attributes are not automatically perceived as central to the product’s identity. Instead, their perceived centrality depends on whether they fit users’ expectations about the product’s structure and function. For example, the stackable frame modules in the shelving system were viewed as a peripheral attribute, likely because participants are familiar with fixed shelving. In this case, stackability was perceived as an optional benefit (thus peripheral) rather than a central-defining attribute. Similarly, for the other products, perceptions of centrality varied substantially, suggesting no consensus among participants on how such attributes contribute to product identity. For example, in the desktop PC tower, 36% of participants perceived the “replaceable internal components” as a peripheral attribute, while another 36% considered it as a central attribute. This variety of results suggests that some participants considered the attribute as central due to its implications for upgradability, repairability, or customization, whereas others viewed it as peripheral because, despite these benefits, a desktop PC tower with “fixed internal components” can still function effectively. This pattern reinforces the idea that the same attribute can be perceived as central or peripheral depending on individual expectations. This highlights the role of functional expectations in centrality judgments.
Regarding RQ2 and RQ3, these centrality assessments did not necessarily predict sustainability perceptions. Although the centrality perceptions varied across products, overall sustainability ratings were consistently high. Only for those products in which the connection between the highlighted attribute and environmental benefits was not immediately apparent, some participants rated the sustainable and “conventional” (same product without the sustainable attribute) versions as equally sustainable. This suggests that sustainability perception depends not only on the presence of a sustainable attribute, but also on how clearly that attribute communicates environmental value. The weak but statistically significant correlation between perceived centrality and perceived sustainability (rho=0.121, p=.018) supports this idea (RQ3). Participants’ sustainability assessment appears to rely more on familiarity, salience, and interpretability of the attribute’s environmental benefit than on its centrality. For example, the automatic shut-off sensor in the electric kettle was clearly linked to energy saving and perceived as sustainable. However, there was no consensus on the centrality of its attribute.
Since perceptions of centrality are highly context- and product-dependent, these findings highlight the importance of shifting the emphasis from attribute centrality to user understanding and perceptual clarity as key factors influencing sustainability perceptions. Future work might validate this deduction, as detailed at the end of this section. From a design perspective, the results suggest that simply integrating a sustainable attribute into a product’s core structure may not improve its perceived environmental benefit unless users can clearly identify its relevance. Therefore, designers should focus on making sustainability-related attributes visible and interpretable, ensuring that users recognize how they contribute to environmental performance. This perspective aligns with prior research on eco-labels, which similarly emphasizes that the effectiveness of sustainability communication depends on the clarity and interpretability of the information provided to users (e.g., Reference Donato and AdıgüzelDonato & Adıgüzel, 2025; Reference Hoffmann, Stork, Madysa and BorgianniHoffmann et al., 2025).
This study contributes to the growing discussion on the link between attribute centrality and sustainability perception by showing that the trade-off between sustainability and performance cannot be fully explained by attribute centrality. Instead, what seems to matter most for sustainability perception is whether users can easily notice, understand, and value the environmental purpose of a design attribute. Therefore, future research could build on these insights by:
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• Exploring how sustainable attributes can be made more understandable and salient to users, particularly those that are technical and do not involve explicit user interaction. This could include exploring which design factors enhance the visibility and recognizability of sustainability benefits, as well as how product type (hedonic vs. utilitarian) or user prior knowledge influences how people judge the relevance and meaning of sustainable design attributes.
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• Investigating whether perceptions of centrality change when the sustainable design intention behind the attribute is explicitly communicated. It is noteworthy that this study explored centrality perceptions without revealing to participants that the products were intentionally selected because of some sustainability-related features. This future work option could be approached in two ways: (1) by asking participants to evaluate sustainability before the centrality questions to observe potential shifts in interpretation, or (2) explicitly stating why the highlighted attribute contributes to environmental performance.
Future research could also extend this study by examining a broader range of product categories and eco-design strategies to further validate and generalize the observed perception patterns. It is worth mentioning that the results presented are affected by several limitations. First, the survey included visual and textual representations of products, but actual interaction with physical products might lead to different perceptions of attribute centrality or sustainability. Moreover, although neutral and unbranded product representations were used, perceptions may still be influenced by the specific product models or visual examples shown. Additionally, completion time could have affected participants’ attention, potentially influencing the reliability of centrality judgments. Despite these limitations, this research provides a first step toward understanding how users perceive the centrality and sustainability of eco-design attributes, offering a basis for future experimental and design-oriented investigations that involve direct interaction with products.
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