Your friendly guide to sustainability


The current gateways for smart lighting systems, such as the Hue Bridge, provide no extra value for the users besides of their connective properties. As a result, they are often placed at an inconspicuous place somewhere in the living room. Hana uses this is an opportunity and turns the smart lighting gateway in a decorative artifact that helps users in saving energy, by providing feedback on the sustainability of their light settings.

The aim of the product is to tackle a sustainability problem called the rebound effect of lighting: which states that as lighting becomes more efficient, our demand for it grows. In the domestic setting, this is shown in the form of ambient lighting. Obviously, we should still allow lighting to be used as “decoration”, as it greatly enhances the user experience, however if we aim for a more sustainable world it needs to be used in moderation. 

Design process

The design process followed a double diamond model. The project started with a thorough user and context study. User peronas and problems were defined based on the research. multiple ideas were developed that were, after evaluation sessions, narrowed down to one. A quick video prototype of the final idea was made to validate with users with the “co-constructing stories” method. 

Inspired by the results from the sessions, refinements were made to the concept. Additional literature was also used as inspiration. A high-fidelity, functional prototype was made using Arduino. This final prototype was used for a final evaluation session with potential users.


The process started with a thorough research phase consisting of literature research and a cultural probe study.  The goal of the cultural probe study was to identify people’s attitude and desires when it comes to domestic lighting and sustainability. The probes were exercise booklets that were distributed among several households. As the majority of the exercises were about lighting, the participating households were asked to do them in the evening as a family exercise. Discussion between family members was encouraged.

Key Finding

Sustainability is something that is valued among all the participating households. However, they all mentioned that they had difficulties in maintaining a sustainable lifestyle for a longer period of time. This due to, forgetfulness, laziness, but also a lack of awareness.

“When we read or see something in the news about sustainability we often try to live more sustainable. But, it’s difficult to maintain it and as time passes we simply revert to our old lifestyles”  


The findings of the cultural probes were summarized into a couple of problem scenarios. These scenarios acted as a tool for idea generation.

“When we read or see something in the news about sustainability we often try to live more sustainable. But, it’s difficult to maintain it and as time passes we simply revert to our old lifestyles”  


User interviews, sketching and prototyping played an important role through the whole process. A participatory approach was adopted, and scenarios and concepts were reviewed together with users.

Key Finding

During the co-constructing stories sessions with users, I discovered that people attach a lot of emotional value to lighting – and by focusing too much on sustainability we would undermine that aspect. The new challenge was to find a balance between people’s emotional satisfaction and sustainability.

“Sometimes it is nice have some extra lights during a movie for example. Having ambient lights with certain movies just makes it much more exciting.”

Final solution

The final solution was a replacement of the smart lighting gateways (e.g. Hue Bridge). Based on gathered data on the outside weather and current light usage, the system judges whether the light setting is sustainable or not.

During the interviews, the participants mentioned that they found it important that they were still bosses of their own home. Although they liked to have system that would help them in saving energy, it was important that the users still had the last word. Hence, the product only gives information, and does not choose a light setting on their own.   

“People are social beings that are capable of taking each other’s needs into consideration if sufficient information of the social context is provided” (as cited in Niemantsverdriet, Broekhuijsen, van Essen and Eggen, 2016)

Companion app

A companion app was designed to give the users more insights about their energy usage, as well as adding a more refined interaction of controlling the lights. 

The interface visualizes the preferences of the system. The user can choose a sustainable light setting by staying within the colored bars. This interface is inspired by the principles of social translucency (Erickson T, Kellogg WA, 2000) which states that “systems should respect the principles of visibility (making significant social information available to users), awareness (bringing our social rules to guide our actions based on external social cues) and accountability (being able to identify who did what and when) in order to allow people to effectively facilitate users communication and collaboration in virtual environments.”

Final evaluation

For the final evaluation, a high-fidelity interactive prototype was build. The prototype was then reviewed together with potential users.

As a similar product does not exists on the market yet, participants were unfamiliar with some of its interactions. However, they all mentioned that it was very easy to learn. They also believed that it would help them in creating more awareness of their light setting and suggested that such a system can be expanded into other energy areas such as heat control and electricity.

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