In the world of research and development, we’re all looking for the magic formula: a way to accelerate impact by gathering the robust insights needed for successful scaling. The Start at Home pilot project, an initiative by Nesta, delivered in partnership with the Scottish and Northern Ireland Plumbing Employers' Federation (SNIPEF), exemplifies how social innovation and agile, practical thinking can do just that. This is a behind-the-scenes story of how we learned as we went, even when faced with the unpredictable nature of real-life piloting of an innovative idea.

The success of the UK's net-zero ambitions hinges, in part, on a crucial question: can we get heat pumps installed at scale? To do this, the UK needs far more active heat pump installers. While training for heat pump installation is on the rise, a significant gap exists between theoretical knowledge and practical application. We’ve heard from many newly-trained installers that they often struggle to gain the crucial first-hand experience needed to confidently install heat pumps in customers' homes, leading some to move away from heat pump installations. This "first-install" problem creates a bottleneck, hindering the transition to low-carbon heating. Social innovation demanded a swift, impactful intervention.

The Start at Home project offered a direct, pragmatic solution: provide newly-trained installers with a free air source heat pump to install in their own homes. A randomised controlled trial (RCT) would have been ideal for robust evidence, but our timelines, budget and limited pool of plumbing and heating professionals made a full-scale trial impossible. Nevertheless, we tried a small pilot, recruiting 40 engineers and randomly allocating a free heat pump to 20 of them, with the remaining 20 participants forming a “control group.”

But logistics and personal commitments quickly meant we couldn't stick to the plan, as we couldn't compel anyone to install a heat pump in their home. When some of the initially selected installers declined the offer and asked to be moved to the control group, we could have stopped the project and started the recruitment campaign over.

Instead, we shifted to a self-selection approach, meaning we ended up offering a heat pump to everyone in the project. This approach proved successful because it mirrored real-world conditions where highly-engaged individuals pursue training and development based on their own motivations, needs and availability.

Our research didn't follow a strict RCT model. Instead of a randomly assigned control group, we compared installers who decided to install a heat pump at home to those who declined our heat pump offer. While this isn't a textbook setup, it highlights how adapting your research design can still yield robust, real-world insights. By being upfront about the limitations and framing them as potential effects rather than strict causal claims, this flexibility kept the project moving forward and allowed us to make meaningful observations.

Our methodological agility extended beyond the initial setup. We continuously monitored our approach to data collection, ready to pivot when something wasn't working. For instance, we initially used a new app-based diary method called FieldNotes to collect rich, multimedia entries from installers. However, after three months, only 9 out of 36 participants (four participants had dropped out by that time) were actively engaging with it. We quickly recognised that this method wasn't resonating with our participants. We decided to stop using the app altogether, favouring direct phone calls and texts which installers preferred and felt more comfortable with. This willingness to "ditch" a method that wasn't effective allowed us to maintain strong engagement and gather the valuable qualitative data we needed.

To ensure the project remained deeply grounded in the realities faced by installers, we fostered continuous, direct engagement. We maintained regular contact with installers via email and phone, and through our delivery partner SNIPEF, actively listening to their concerns and adapting to their needs. This meant, for example, moving installation deadlines to accommodate busy winter schedules - a peak time for plumbers. These regular, responsive check-ins were vital for project success and participant satisfaction.

In addition, we established a "scaling group" that met four times over the year. This group, composed of industry stakeholders, UK and devolved governments and combined authorities, who could potentially scale the scheme, provided ongoing feedback and ensured our findings were relevant and actionable for broader implementation by the organisations best placed to scale the scheme.

Through continuous adaptation, the project generated usable and insightful findings, focusing on the real experiences of installers across both groups. We ensured our reporting was transparent, avoiding over-claiming while still leveraging the rich data gathered. Comparing the experiences of the engineers who installed a heat pump after training completion with those who only attended heat pump training, four key findings emerged:

1. Boosted confidence and knowledge

Installers who fitted a heat pump at home reported significantly increased confidence and a deeper technical understanding, especially in areas like system design, heat loss calculation, and commissioning.

2. Enhanced understanding through lived experience

Living with a heat pump provided continuous learning opportunities, allowing installers to monitor performance, optimise efficiency, and gain invaluable insights into user experience - knowledge directly applicable to their customers.

3. Pathways to certification

The home installation served as credible evidence for installers pursuing MCS certification, a vital step for offering government funding schemes to customers.

4. Credibility and promotion

First-hand experience with a heat pump strengthened installers' ability to promote the technology, backed by real-time data and personal insights. They could confidently discuss energy consumption and even invite customers to see their own installations.

To ensure the robustness of our findings, we triangulated data from quantitative surveys with two rounds of in-depth qualitative interviews within each group. This allowed us to contextualise the findings and stay grounded in the lived realities of the installers. We reported on the experiences of the two groups alongside one another, highlighting insights without making strict causal comparisons.

The success of Start at Home underscores the critical role of social innovation organisations like Nesta. These organisations don’t just stop at identifying problems; they design, build, and test practical solutions in the real world. This hands-on, adaptive approach allows them to quickly accelerate impact and create valuable and scalable learnings. This is because they excel at:

• Rapid prototyping and piloting: Instead of extensive theoretical frameworks, they design and implement practical pilots to test solutions directly in the field, gathering real-world data quickly.
• User-centered design: They deeply understand the needs and barriers faced by the target audience (in this case, heating engineers) and design solutions that directly address those pain points.
• Facilitating collaboration: Nesta partnered with SNIPEF, leveraging their recruitment capabilities, technical support, and industry connections to ensure the project's success. This cross-sector collaboration is often a hallmark of effective social innovation.
• Focus on scalable solutions: The project wasn't just about the 36 pilot participants; it was designed to identify a scalable solution for thousands of installers across the UK, emphasising widespread impact over isolated academic findings.

The Start at Home project is a strong example of how agile, practical research can achieve tangible, real-world results. By embracing the realities of implementation - from taking inspiration from experimental designs and adapting on the fly to quickly ditching methods that didn't work - Nesta and SNIPEF have not only empowered individual installers but have also laid a foundation for accelerating the UK's journey towards net-zero.

Following the pilot's positive results, Nesta is leading this innovative scheme to scale. We've spoken with a wide range of organisations, including manufacturers, trade associations, and government bodies, to explore how the Start at Home approach could be offered across Great Britain. These conversations have already led to the independent launch of six new Start at Home schemes for heating engineers in Great Britain. To support this growth, we’re hosting a website to help heating professionals easily compare available options and to assist scheme providers in promoting their offers.

The most effective research isn't just about what and how you study, but how quickly and practically you can implement solutions and adjust your methods to the real world while still deriving valuable insights. The rapid expansion of Start at Home schemes proves that agile innovation is a powerful method for exploring social solutions that are effective and highly scalable.