The Council was interested in piloting the Wondrwall system as it provides a low-carbon alternative to traditional convection heating and help it transition its housing stock from gas to low-carbon heating. Additionally, the Wondrwall system combines a number of technologies aimed at reducing energy consumption and bills and can be fitted quicker than other low-carbon heating systems, meaning that properties can be retrofitted and made available to new tenants more quickly.

With this in mind, the pilot aimed to:

• explore the user experience of tenants using the Wondrwall system
• understand the suitability of Wondrwall technology for decarbonising council properties
• understand the effect the Wondrwall system has on energy consumption.

Nesta collaborated with Newcastle City Council, Equans and Wondrwall to provide independent qualitative research to evaluate the two households’ experiences of the new Wondrwall system throughout the autumn and winter of 2022/23.

This report aims to summarise Nesta’s findings of the users’ experiences and provide guidance for other social housing providers considering installing these systems in social housing or council properties.

The properties included in the research were two-bedroom terraced houses on the same street in Newcastle. The two houses had almost identical layouts. Neither property had any fabric improvements done prior to being fitted with the Wondrwall system. The decision to not include any additional fabric improvements was made in order to better understand the performance of the Wondrwall system as a ‘like for like’ swap of the existing gas boiler system and to pilot the technology in houses that were representative of the council’s housing stock.

Property A was a mid-terrace house with an EPC rating of C and property B was an end-of-terrace house with an EPC rating of D (as of November 2021).

Both houses were fitted with Wondrwall technology before the tenants moved in, which included: ceiling-mounted intelligent infrared heating panels, intelligent light switches, a thermal battery for hot water, a solar PV array, a hybrid inverter and a residential battery.

Infrared panels use electricity to create 100% radiant heat, which heats surfaces, objects and people directly. This means that, unlike traditional radiator based systems, they don’t rely on heating the surrounding air and have higher efficiencies than condensing gas boilers. However, given that electricity costs significantly more than gas, used by themselves, infrared panels could be more costly to run than a gas boiler.

The Wondrwall system combined a number of technologies aimed at reducing energy consumption and costs. The heating was controlled by an intelligent programming system that allowed users to schedule and heat zones individually. The system used motion sensors to detect room occupancy and automatically heated the rooms that were in use. The solar panels and battery storage aimed to help lower energy consumption further by generating energy and storing the energy created from the solar panels, as well as cheaper off-peak energy drawn from the grid. With this in mind, users could benefit from being on a special tariff such as Octopus Go or another similar Electrical Vehicle (EV) tariff that allowed them to access cheaper off-peak rates overnight to charge their battery.

By combining these technologies, Wondrwall claims to be able to bring down energy bills to about a third of those using a combi gas boiler (1).

There is relatively limited understanding of the user experience of whole-house infrared heating systems, particularly in a social housing setting. Existing studies looking into the experience of social tenants with low-carbon heating technologies point to risks such as comfort-taking behaviours (where consumers increase their energy use because the heat is perceived as being cheaper), issues with not being able to heat rooms to the required temperature quickly enough and tenants being wary of using the controls without the assistance of their landlord. A 2018 report by National Energy Action recommended that infrared technology should not be installed in homes of those at risk of fuel poverty, particularly if their homes need to be continually heated.

To address this gap in knowledge Nesta conducted qualitative research and evaluated two households’ experiences of the new Wondrwall system throughout the autumn and winter of 2022/23.

The research aimed to investigate the tenants’ experiences of using the system during a heating season and explore their experience of:

• being introduced to the system
• adapting to and controlling the system
• managing the winter peak and thermal comfort.

This research did not focus on determining whether the system saved energy , as the small sample size would have compromised the methodological soundness of the results.

Nesta conducted at total of six qualitative interviews and two property visits with two tenants between August 2022 and March 2023 and one interview with the Wondrwall technical support staff member that had the most contact with the tenants during this time.

Throughout the six months of the trial, the participants’ engagement with the research as well as the onboarding process was low, as the tenants were often unavailable for interviews and appointments. While this did not majorly impact the research process (interviews were rescheduled), the low level of engagement impacted the running of the pilot, as both Wondrwall and the Council had difficulties onboarding and supporting the tenants, which, in turn, impacted their ability to use the system most efficiently.

The participants (2) were recruited with support from the Council. The properties were fitted with the heating system when empty, then advertised to prospective tenants through the Council’s social housing system. The house listings mentioned that the houses had been fitted with the Wondrwall technology and that by moving into the properties, they were agreeing to being part of the research. The participants were given the option to withdraw from the study at any point, without having to give a reason for this.

Interviews were conducted over the phone and in person and interview notes were taken during each one.

Chris was in their early 20s at the time of the research and lived in the house with their one-year-old child. Their partner lived in the property on a part-time basis. They didn’t have a set schedule and rarely left the property. Before moving to their new address, they lived in a flat with their parent, which was heated via radiators (the type of their previous heating system is unknown). This meant that they had limited previous experience of managing their heating and bills.

Ali was in their mid-30s and lived in the house with their partner and two children (both under four years old). They were mostly at work during the day, while their partner was mostly at home with the two children. Prior to moving into the property, the family lived in a two-bed flat with a gas boiler, traditional radiators and thermostat. They previously managed their energy use by using the thermostat to turn the heating on and off or setting a timer, for example, at night or when they were out.

Wondrwall replicated their regular onboarding process with the tenants, which involved contacting the tenants via phone prior to moving in, followed by a home visit upon moving into the property. During the home visit, the tenants were introduced to the system and controls and Wondrwall staff set up a schedule for heating, based on what the tenants told them about their preferences and daily routines.

Reflecting later, the Wondrwall staff member thought that, at the point of moving into their new home, tenants found it challenging to focus on the onboarding process. Upon moving into the property, the tenants were provided with a significant amount of other information related to their tenancy, which could mean that their heating system was not a priority, particularly given that the heating season had not yet started.

Chris expressed that they were initially worried that they might find using the Wondrwall system difficult and might need to access out-of-hours support if they were struggling. They reported finding the induction process, as well as the system, confusing. As a result, they contacted the Council via email on a number of occasions with various questions. The Council and Wondrwall arranged a number of support visits, which were cancelled or unattended by the tenant, making it difficult to receive tailored support during this stage.

In contrast, Ali found the Wondrwall system “very surprising” and appreciated the space-saving and safety aspect of the infrared panels, particularly given their young children (as there are no hot radiators within children’s reach). They reported that they were pleased with having the system installed in their home and that friends and family also found it intriguing. They reported no problems with the induction process itself, but did flag some minor initial issues with the system not being connected to their smartphone straight away and some light switches not working. These issues were resolved quickly by Wondrwall.

The tenants had mixed experiences of using and controlling the Wondrwall system.

Chris expressed low overall satisfaction levels with the system and difficulty adapting to it, particularly when it came to changing settings and understanding how the heating worked.

Chris and their partner avoided touching the central system controls out of fear of breaking the system and shared that they “found the system quite confusing”. Their confusion with using the system led to them requiring almost weekly over-the-phone and in-person support from Wondrwall. Some of the issues that required support included the “the heating not being hot enough”, a damaged button and an electrical fault. While they were able to contact Wondrwall for support whenever they needed, sometimes a few times a week, they noted that the Council was less knowledgeable about the system and was not able to troubleshoot issues for them.

Chris expressed dissatisfaction with their ability to control the system. They disliked the fact that the system turned on and off by itself (due to the schedule that was set during the initial set up) without the option of easily turning the whole system off. They were unsure of how to change the temperature, and said that their house was often too warm. They preferred the level of control they had with their previous radiator based system, but were unsure whether they would prefer to go back to having a traditional heating system, as they still appreciated “how techy it is”. While running the system was confusing, they appreciated the availability of smart features such as the ability to control the heating on their smart phone.

Ali expressed higher levels of satisfaction with the use of the system, but low satisfaction levels with the resulting energy use (discussed below). Unlike Chris, they found the Wondrwall system convenient and easy to use, particularly when it came to controlling the heating and lighting remotely with their smartphones. They said that they would probably not go back to a traditional heating system if the issue with the high energy consumption was resolved, although their partner said they still preferred gas and traditional heating with radiators. They also contacted Wondrwall for support on a regular basis and felt that the Council was less knowledgeable and able to support them. Both the Council and Wondrwall supported the tenants over the phone or in person on a regular basis, but reported this was often made difficult due to the tenants cancelling or not showing up to appointments.

Tenants reported that the system generally performed well in winter, keeping their homes warm when they used it. Both participants said that on some occasions the system would unexpectedly turn itself off, even when the room temperature was below the set threshold.

Chris reported that their house was warm throughout winter and that they preferred to keep most rooms at a temperature between 20 and 22°C, but that their house was often too warm because the system turned itself on regularly. The temperature measured by the system (discussed in the following section) was significantly higher than their reported ideal temperature.

Ali found the heating to be adequate when the system was on, but reported that it took a long time for the house to heat up, which in turn, led to high energy consumption and electricity bills, which forced them to reduce usage.

Both tenants reported using a secondary heating source (electric radiator) on really cold days.

Both tenants had higher than average energy consumption over winter, which was mostly driven by their heating usage.

Chris had the higher energy use of the two, with an average monthly consumption of 1,449 kWh and a total energy consumption of 10,141 kWh between September and March. Although we were unable to track their energy consumption over a whole year due to the constraints of this study, their total energy use between September and March was already higher than Ofgem’s predictions for the mean annual electricity consumption for low-income households (5,120 kWh), and for all other electrically heated households (7,674 kWh) (3).

Some of this consumption was expected to be offset during summer (after the end of the pilot), when their solar panels should generate more energy compared to the winter months. Wondrwall predicted Chris’ property would generate 3,456 kWh over a full year, which, when accounted for, brings the September to March consumption figures to 6,685 kWh (4). This is still higher than Ofgem’s mean annual electricity consumption for a low-income electrically-heated household, despite only covering seven months of the year.

These energy consumption figures could be explained by the temperature data collected by Wondrwall. Chris had an average home temperature of 24°C in January and regularly heated rooms such as the kitchen and the master bedroom at even higher temperatures of 27°C and 25°C.

Given their total energy consumption and taking into account their solar generation, we estimate that participants’ bills covering September 2022 to March 2023 are likely to have been around £3,200 (5).

Chris said they had not received any information on their energy use or bills from either the council or their energy provider (as of March 2023). This is because their energy provider placed them on a half yearly payment cycle, meaning that they were not issued a bill during the first six months of living in the property. Their attempts at moving onto a monthly payment plan were unsuccessful. The Council said they had advised the tenant to move to a different supplier as soon as they were made aware of the six-month billing plan and offered to support with the switch, but that the tenant did not take them up on the offer.

Chris also did not have an in-home display and smart meter fitted in their property. This meant that they were unaware of their high energy consumption throughout the winter. Towards the end of the six-month period, with support from the Council, they moved from British Gas to Octopus Energy and, while they had still not received a bill for the five months from British Gas, they had received a bill for £400 for their first month of using Octopus Energy as their provider, which was higher than they expected.

Ali’s property had lower energy use compared to Chris’, but still higher than average. Ali’s average monthly consumption was 1,169 kWh and their total energy consumption between September and March was 8,186 kWh.

Wondrwall predicted Ali’s property will generate 2,303 kWh over a full year, which, when accounted for, brings the September to March consumption figures to 5,883 kWh (6). Despite only covering seven months of the year, it is already higher than Ofgem’s predictions for the mean annual electricity consumption for a low-income electrically-heated household (5,120 kWh).

Ali had an average home temperature of 20°C in January and regularly heated rooms such as the living room and kitchen to temperatures of 25°C and 22°C respectively.

Given their total energy consumption and taking into account their solar generation, we estimate their bills covering September to March to be around £2,700 (7). Ali indicated that the high cost of using the system was the greatest drawback of the Wondrwall system. They had been paying for their bills monthly and were very concerned about their high energy usage and resulting high energy bills (they estimated paying around £2,500 since moving into the property), which impacted their ability to use the system consistently. They also noted that, before they received their first bill, they had assumed that their energy bills in the property would be very low. Similarly to Chris, they switched to Octopus Energy from E-On towards the end of the six-month research period.

Participants were told by Wondrwall that they should move onto a special tariff that would allow them to take advantage of the significantly cheaper off-peak rates overnight to charge their battery. Moving to a different tariff was the responsibility of the participant. Neither participant had switched to a recommended tariff by March 2023 and both said that while Wondrwall had mentioned the importance of being on the right tariff to them, this had not been made clear to them by the Council.

This meant that for the duration of the trial, the tenants were unable to make use of the significantly cheaper nighttime energy tariffs to charge their battery. While it is difficult to assess exactly what their energy bills would have been on a different tariff, Nesta believes their bills would have been significantly lower (in April 2023 Octopus Go’s Night Rate for electricity was three times lower than the day rate).

Reflecting on the process of getting the tenants to move to the right tariff, Wondrwall said that this differed from their usual interactions with new system users, who are usually eager to make the most out of the benefits offered by the Wondrwall system.

This project also highlighted the value of piloting these approaches with a small number of properties before considering wider roll-out. Reflections from this pilot can inform the decision-making process for potential wider roll-out by other local authorities or social housing providers. Below, we list our key recommendations for social housing providers looking to pilot or roll out intelligent infrared heating systems.

Tenants appreciated the convenience and innovative features, but faced challenges in adapting to the new technology. Social housing providers should provide clear and accessible support and information for tenants. It is important to provide a comprehensive induction to new tenants that includes a demonstration of how the system works, and clear written instructions.

This should be followed up with regular check-ins and support (both over the phone and in person) to address any lingering concerns and questions. The housing providers should also provide support to tenants who are not comfortable using smartphones, such as printed instructions or training sessions.

Moreover, the tenants mentioned not being able to ask the Council for assistance related to the use of the system. While it is not the social housing providers' role to provide complex technical support on the technology itself, feedback from tenants underscores the importance of good collaboration and knowledge sharing between the social housing and the heating technology providers.

One of the tenants found it particularly difficult to engage with the onboarding process, which negatively impacted their ability to use the system effectively. Tenants’ capacity to engage and, by extension, their experience of using the system is impacted by a variety of factors that should be taken into account such as feeling overwhelmed about moving into a new property, being at risk of fuel poverty, having small children or having limited experience of managing household bills.

Offering additional, tailored support to these tenants, especially those who are vulnerable, is crucial, particularly early on in the process. For example, this could be done by prioritising key information (such as setting up the heating schedule and basic functionalities) during the onboarding process. Additional information could be provided gradually over time or made available through easily accessible resources.

Moreover, housing providers should consider whether some tenants might be more comfortable with more traditional user interfaces that don’t require as much tweaking or that have simplified controls designed specifically for social housing.

Being on a monthly payment plan and the right electricity tariff is key to ensuring that the potential energy savings are realised. Social housing providers should collaborate closely with utility providers to ensure tenants have access to appropriate tariffs and billing plans that maximise the benefits of solar generation and battery storage. Ideally, an appropriate tariff should be set up before the tenant moves in, rather than relying on the tenant to switch to an appropriate tariff themselves.

Both tenants had above average energy consumption throughout winter, which could, in part, be explained by the tenants increasing their energy use because the ‘clean’ or ‘green’ heat was perceived as being cheaper than gas heating. To mitigate against this, tenants need to understand how much energy they are using and how much it is costing them. The tenants should be provided with clear information about energy consumption and costs, including regular updates on usage and bills. This information should be displayed in different formats to aid accessibility. In Home Displays (displaying information from a smart meter) should be provided to help tenants to monitor their daily energy spend. Recent evidence suggests In Home Displays (displaying information from a smart meter) could help householders to make informed decisions about their energy use and can help them to budget effectively.

Low-carbon heating technologies have the potential to save tenants money on their heating bills. However, the expected savings are not always realised due to issues with installation, tenants being unable to access the best tariffs or to use the system as it was designed. While social housing tenants are generally responsible for paying for their own energy bills, social housing providers piloting new technologies should plan for what will happen if the expected energy savings do not materialise.

This could include, for example:

• reimbursing participants for part of their energy costs incurred during the pilot
• at the end of the pilot, offering the option to have their system altered to better meet their needs, or offering the option to move to a different property.

Social housing providers considering implementing similar intelligent low-carbon heating technologies should focus on providing comprehensive support for tenants and work closely with energy suppliers and the technology providers to ensure a seamless user experience while avoiding unnecessarily high energy costs.