Housing represents about 29% of the total energy consumption in Europe and contributes with around 20% of emissions (European Commission 2013). Social housing represents about 12% of the total European housing stock and therefore is a significant target for energy efficiency measures by governments of EU member states. This paper is aimed at exploring how an innovative serious game could contribute to energy consumption and carbon emissions reduction in social housing by increasing the social tenants’ understanding and engagement in energy efficiency. The proposed solution is being developed under the auspices of the EnerGAware project (Energy Game for Awareness of energy efficiency in social housing communities), funded by the European Commission under the Horizon 2020 programme. ness, energy knowledge, social media activity, ITliteracy and socio-economic status and health is also described. 2.1 Eliciting requirements A comprehensive identification and analysis of the specific user, building and game requirements that are necessary to design the EnerGAware integrated serious game and metering system solution was carried out. Requirements were defined using a range of different datasets and methods including (1) literature review; (2) a large-scale, city-wide survey, undertaken in Plymouth, UK, during 2015, which was administered to all the 2,772 social houses managed by the social housing provider partaking in the EnerGAware project; (3) three game-play scenarios focus groups undertaken with social housing tenants in Plymouth, UK, during 2015 and (4) asocial housing building stock database gathered and managed by project partner DCH (Building Stock Condition Database). 2.1.1 User requirements Results suggested that the EnerGAware serious game virtual world should be based on a domestic environment (e.g. virtual home), so as to help the players to relate to. Results revealed the existence of a large group of older people, high presence of retired people and a large group with low educational level, suggesting that the EnerGAware game should put special attention when designing the visual aspects of the game to those requirements derived from human aging process and novice users. In relation to the didactic approach of the game, the game should adapt to different learning levels and provide clear and easy to understand goals. Regarding the educational content, the game should allow users to learn how to balance the energy consumption, comfort and financial cost of a house; gain knowledge on how much energy is used by the typical end-uses existing in a domestic environment, poor practices of use that might increase the energy consumption, as well as the most efficient ways to use them to save energy. The game should also help the player to assess the potential energy savings from different behaviour actions and energy-efficient changes to the virtual house. From the game functionalities point of view, the link to social media platforms to enhance communication and information sharing amongst players was found relevant. 2.1.2 Building requirements The most common building characteristics, building envelope, building services and controls and renewable energy generation were analysed and transformed into the ‘typical’ social dwelling which was used to influence the design the virtual home contained in the EnerGAware serious game. Data related to the energy metering and monitoring systems existing in social homes (e.g. smart meters, end-use metering, etc.), internet availability and coverage was used to design the energy metering and data communication infrastructure. 2.1.3 Game requirements Results validated that a significant part of the social tenants have a good IT-literacy, Internet and social networks habits, and experience in playing video games. Therefore, the results suggest that the online serious game approach adopted for the EnerGAware serious game should not be a barrier for the targeted audience. Both the focus group and the Social Housing Survey results suggested that the EnerGAware serious game should be an energy management game (home management, resources management) focused on a virtual house customization game. Regarding the graphical aspect and the setting of the EnerGAware serious game, the results of the Social Housing Survey suggested that this is not a major criterion of game choice for the targeted players. However, the focus groups concluded that a pseudorealistic game setting would be better than a fantasy world (or sci-fi, or cartoon) and better than a fullyrealistic simulation. A tactile tablet was identified as the most suitable IT device (both technically and cost-effectively) for the deployment of the EnerGAware serious game. 2.2 The EnerGAware concept The serious game will allow users to design their own virtual home using a simple drag-and-drop interface. The users will have an initial limited financial budget (in-game currency) available to construct their house and choose domestic appliances, lighting and furniture. Users will be able to earn in-game rewards to upgrade their home and buy more in-game objects by improving the energy efficiency of the house (e.g. increase insulation) or change the game characters energy efficiency behavior. A building energy consumption simulation engine (Figure 1) will calculate the current energy consumption of the virtual house and provide the potential options for improving its energy efficiency. The options provided will demonstrate the potential energy savings from (1) upgrading buildings’ envelopes (i.e. no insulation vs. cavity wall insulation or solid wall insulation, etc.); (2) replacing the existing domestic appliances and lighting (i.e. incandescent bulbs vs. CFL bulbs or LED bulbs, etc.); and (3) user behaviour change (i.e. reducing heating and cooling temperatures or durations; leaving appliances in standby mode, etc.). Users will be able to click on appliances and HVAC devices in the game and receive feedback about the energy consumption in different modes (e.g. active, standby, off; set-point temperatures; heating/cooling periods). Figure 1. EnerGAware serious game schematic. The successful balancing of energy consumption, comfort and financial cost will lead to the user generating extra in-game rewards which can then be reinvested in the home. The user will need to decide whether to invest in low cost options providing low energy savings (i.e. replacing plasma by LED TV, installing draft excluders, etc.), or high cost options providing high energy savings (i.e. solid wall insulation, solar photovoltaic panels, etc.) with the latter taking more time to save up for. In addition, the user will be able to play a series of missions related to energy use integrated into the main EnerGAware serious game. These will contribute to increase energy awareness and will provide the user with an opportunity to earn further in-game rewards. The EnerGAware serious game will also be connected to the actual energy consumption (smart meter data) of the house in which the user lives (Figure 1). This connection will have three purposes; firstly, real world energy savings will translate into in-game rewards; secondly, the user will be able to view their current and historic energy consumption of their homes’ through the serious game interface; and thirdly, to validate the energy savings achieved in the real world from playing the serious game. Finally and as shown in Figure 1, the EnerGAware serious game will be embedded in wider social media and networking tools (e.g. Facebook, Twitter, etc.). In the simplest form, these links with social media and networking tools will be used to disseminate the game and enable users to enter or reenter the serious game from potentially anywhere in the world, thus reducing barriers to participation and encourage large scale uptake beyond the project’s lifetime. The social media features will also provide users a platform to share data of their achievements, compete with each other, give energy advice, as well as, join together to form virtual energy communities. 2.3 The EnerGAware game mechanics As shown in Figure 2, the cat is the main character of the game and the only one that can be controlled by the player. The human characters living in the virtual house are non-player characters controlled by the computer. They have non-energy efficient behaviours, which the cat will try to address. Neighbors may request the player’s help in several kinds of situations (e.g. advices to choose an energy provider or actions such as turning off all the lights). Within the house customisation mode, the player is able to create his/her dream house. An editor function allows the player to buy appliances, furniture, decoration items and energy efficiency upgrades (e.g. wall insulation) in a realistic environment. A mission mode provides knowledge about energy efficiency and educates the player about right energy management behaviours. Missions take place in neighbours’ houses with a fixed geometry that substantially ease energy consumption simulations. The mission mode also shows ideas about how the player’s house could evolve. The main gameplay loop starts with a daily pool of energy points. The player has an operational house with a global energy consumption and she/he will have to save energy points to complete energy efficiency objectives. It will allow him/her to unlock game content, mainly new items and upgrades for already owened items (e.g. appliances, insulation). New items might be more efficient, i.e. consume less energy points (e.g. a more energy efficient fridge), or just be a smarter version (e.g. a bigger TV). Figure 2. Screenshot of the EnerGAware prototype. If the player chooses the more energy efficient item, this will impact favourably the global energy consumption. Upgrades and new items will increase global happiness which will in turn increase daily money income. Money is then used to buy upgrades and new items.