RS2: Reimagining Retrofit for Scale and Trust

When it comes to decarbonising homes, two themes keep coming up: trust and simplicity. 
Residents need to understand what’s happening in their homes, landlords need confidence in delivery, and funders need to see a model that stacks up commercially. 

That’s the gap Tom Woolley and the team at SMS (soon to be rebranded under a new group structure following their merger with Horizon and SMA) are determined to close. With 600 engineers nationwide, years of experience in smart metering, and serious backing,  including KKR’s capital,  they’ve built something that sits between investment and innovation: a solution-based business designed to make the energy transition scalable, profitable, and trusted. 

A Model That Lives for the Lifetime of the Technology 

The group’s journey began with a set of fundamental questions: 

• Why aren’t more people engaging with low-carbon technology? 

• What stops retrofit from becoming mainstream? 

Their research pointed to five recurring barriers: interest, trust, understanding, simplicity, and support. 

Out of that, they created MIS, not just a brand, but a toolkit for local authorities, housing associations, and social landlords. It’s white-label ready, meaning it can sit under a landlord’s own brand to build trust with residents while SMS provides the engine underneath. 

This isn’t just about funding and installation. It’s about supporting the technology through its entire 25-year lifecycle;  managing batteries, inverters, replacements, and ongoing optimisation. The model is designed to stick around, not disappear after installation. 

Five Steps to Simplicity 

SMS has streamlined retrofit into a clear five-step process: 

1. Make sense of energy data.  Use smart meter data to understand real household energy use. 

2. Design the right solution. Size PV and battery systems to suit consumption patterns. 

3. Simplify the experience. Make retrofit as easy as taking out a mobile phone contract. 

4. Deploy with confidence. Manage subcontractors and tenant engagement for seamless installation. 

5. Stay for the long term. Provide monitoring, maintenance, and replacements across 25 years. 

The aim: deliver retrofit that feels simple but performs complexly behind the scenes. 

The “Home Comfort” Model 

At the heart of the proposition sits a subscription model designed to deliver real savings and create a win–win between landlords and residents. 

On an average home with 8 PV panels and a 5.2kWh battery: 

• Energy bill reduced by: ~85% 

• Tenant pays a “Home Comfort” charge: £53/month 

• Landlord position: Net profit of around £295/year 

• Overall net saving to tenant: ~25% reduction in total energy costs 

Residents stay in the energy market (retaining price cap protection, dual-fuel discounts, and 5% VAT on imported electricity), while landlords benefit from export and flexibility revenue. 

The model is off balance sheet, fully or part-funded (with grants integrated where possible), and includes O&M and asset replacement within the subscription. 

Real-World Proof: Oxfordshire Pilot 

A trial with Oxfordshire County Council tested both engagement and performance  and the results were impressive. 

• A free Energy Saver App, white-labelled to look like an Oxfordshire Council product, helped residents connect to their smart meter data. 

• Even without new tech, app users cut energy use by 9% through personalised insights and behavioural nudges. 

• When offered the subscription model, 65% of residents opted in,  with an 85% conversion to installation after virtual surveys. 

• 302 installations completed in nine months. 

• Average tenant saving: £225/year after paying the subscription. 

Trust the brand, show the benefit clearly, keep the process simple and people choose retrofit. SMS has the capital and supply chain to scale this across hundreds of thousands of homes. 

Flexibility Revenue: Upside, Not Assumption 

The core business case stands without flexibility revenue. Given the domestic flexibility market is still maturing, SMS treats any flexibility income as upside,  often used to build a landlord “buffer” for potential arrears or to further discount subscription costs. 

Data, Security and Supplier Choice 

Cyber risk is real. With experience forged in the smart metering ecosystem, SMS applies stringent security expectations to batteries, inverters and data flows. They’re technology-agnostic, but only work with vetted suppliers that meet robust standards,  a key assurance for landlords. 

Selecting the Right Homes 

Using real smart meter data (from ~890,000 homes), SMS identifies where PV+battery delivers tangible benefit. Not every home will qualify, and that’s fine.  On estate-level programmes, outcomes can be smoothed across the portfolio, enabling a fair place-based approach and consistent messaging. 

Grid Constraints and Place-Making 

Deploying home energy management and storage at scale can materially lower After Diversity Maximum Demand (ADMD), unlocking faster and cheaper grid connections for new and existing sites. In one Oxfordshire development example, smart deployment of 10kWh batteries shifted a projected £90m grid bill to closer to £30m and accelerated connection timelines,  with forward-funded flexibility services providing an additional revenue stream to support the model. 

Heat Today, Heat Tomorrow 

The commercial engine today is PV + battery. But the platform is built for whole-home scenarios: simulate future heat pumps or EVs, toggle technologies on/off, and plan the right sequence (e.g., PV+battery first to cushion future heat-related bill changes). The subscription can wrap multiple technologies; the trick is timing and messaging so residents understand why costs might move later and where the benefits land. 

Resident Engagement: Four Routes to “Yes” 

To build trust and conversion at scale, SMS uses four engagement routes, always optionally white-labelled to the landlord: 

1. Free Energy Insights App (App Store) 

2. QR-code journeys via letters/leaflets 

3. Email invitations with a guided sizing/benefit flow 

4. In-person iPad walkthroughs by tenant liaison officers or community teams 

The key is choice and familiar faces, delivering a landlord-branded experience with SMS tooling under the bonnet. 

Why This Matters 

• It’s simple for residents, bankable for landlords, and built to last. 

• It uses real data, not averages, to design and measure impact. 

• It’s modular and brand-agnostic, so housing providers stay in control. 

• It’s ready to scale, with capital, engineering, and long-term stewardship in place. 

As Tom puts it: “Our mission was to make retrofit as simple as getting a mobile phone subscription...and then stick around for 25 years to make sure it keeps working.” 

Practical Steps for Housing Providers 

1. Use smart meter data to assess your stock. Far more reliable than EPC averages. 

2. White-label the journey to leverage your resident trust and boost uptake. 

3. Explore off-balance-sheet subscriptions with built-in O&M and asset replacement. 

4. Vet suppliers for cybersecurity and data governance as standard. 

5. Plan estate-level rollouts that smooth outcomes and messaging across homes.