Living Energy Passport
And how we're building a better standard together — in the open, driven by data, owned by the community.
Vision
Energy Performance Certificates are the UK's primary tool for rating home energy efficiency. They're also fundamentally broken.Learn how EPC ratings work.
Valid for 10 Years — But Homes Change
A certificate from 2016 may describe a home that has since added solar panels, replaced the boiler, or installed cavity wall insulation. The EPC rating? Still the same. Frozen in time.
Massively Overestimates Energy Use
UCL/SERL research found EPCs overpredict energy consumption by up to 48% for F/G rated homes. The ratings aren't just stale — they're wrong.
Based on Monthly Averages, Not Reality
The SAP methodology uses monthly climate averages and standardized occupancy patterns. It doesn't account for how you actually live, heat, or use your home.
Static Snapshot, Not a Living Document
An EPC is a point-in-time assessment. It doesn't track improvements, doesn't incorporate smart meter data, and doesn't evolve as the grid decarbonizes.
73% of Homeowners Don't Know Their Rating
According to Citizens Advice, the vast majority of UK homeowners don't even know their EPC rating. If the standard doesn't engage people, it can't drive change.
Mission
The UK government is rolling out the Home Energy Model (HEM) in H2 2026 to replace SAP/RdSAP. It's an improvement — but still not enough.
The Good: 30-Minute Intervals
HEM calculates energy use at 30-minute intervals instead of monthly averages — a significant improvement in granularity and accuracy.
The Problem: Still a Government-Controlled Standard
HEM is still top-down, still assessor-driven, and still a point-in-time snapshot. It doesn't incorporate:
- Real-world smart meter readings
- Occupant behavior and usage patterns
- Post-retrofit performance validation
- Continuous learning from building sensor data
HEM is better than SAP — but it's still a static, closed standard that won't evolve as fast as technology does.
Why Continuous Score
Every major country has an energy rating system. None of them solve the core problem.
| Country | Standard | Validity | Key Limitations |
|---|---|---|---|
| 🇬🇧 UK | EPC (SAP/RdSAP) | 10 years | Monthly averages, static snapshot, 48% overprediction for F/G homes |
| 🇬🇧 UK | HEM (2026) | TBD | 30-min intervals, still point-in-time, no real usage data |
| 🇫🇷 France | DPE | 10 years | Similar staleness issues, different methodology |
| 🇳🇱 Netherlands | EP-Online | 10 years | Decent data quality, still static |
| 🇦🇺 Australia | NatHERS | Permanent | Star rating, expanding to existing homes, limited adoption |
| 🇺🇸 US | HERS / Home Energy Score | Varies | Fragmented across states, no national standard |
Different methodologies, same fundamental flaw: they're all static snapshots, not living documents.
Digital Twin Destination
Let's be clear: Passivhaus is the best energy performance standard that exists. It's incredibly rigorous and delivers extraordinary results.
What Passivhaus Gets Right
- ✓ Airtightness testing (0.6 ACH @ 50 Pa)
- ✓ Thermal bridging minimization
- ✓ MVHR (Mechanical Ventilation with Heat Recovery)
- ✓ Triple glazing and super-insulated envelopes
- ✓ Verified performance, not theoretical estimates
But It's Not Practical for Most Homes
- Binary certification: You either meet the standard or you don't. There's no pathway for incremental improvement.
- Designed for new builds: The UK has 29 million existing homes. Passivhaus wasn't built for them.
- Expensive to retrofit: Achieving Passivhaus standard on an existing home typically costs £50,000+. That's out of reach for most homeowners.
- No partial credit: If you insulate your walls but can't afford triple glazing, you get zero recognition. That discourages action.
Passivhaus proves that physics-based, rigorous standards work — but we need one that's accessible to everyone, not just new build budgets.
What We're Building: A Living, Open Standard
We don't have all the answers yet. But we believe the best standard is one that's built in the open, driven by data, owned by the community — not locked behind a government agency or a certification body.
Open Source
Our methodology is transparent, inspectable, and community-contributed. No black box.
Community-Driven
Energy professionals, data scientists, homeowners all contribute to evolving the standard. Not dictated by one government body.
Data-Adaptive
As new data sources emerge (smart meters, thermal cameras, building sensors, HEM outputs), the standard incorporates them. It's a moving target BY DESIGN.
Incremental
Not binary pass/fail like Passivhaus. A 0-100 score that rewards every improvement, no matter how small.
Living Document
Your home's rating updates as you make changes, as energy prices shift, as the grid decarbonizes. Not frozen for 10 years.
Builds on EPC Data
We don't replace the EPC, we build on top of it. Start with government data, enrich with real-world measurements, improve with community input.
This Is an Open Project
We're not claiming we've solved it. We're inviting you to help us build it. The methodology is transparent. The data is inspectable. The standard evolves with the community.
Backed by Real Research
Our standard is grounded in real building science. We've reviewed hundreds of sources — academic papers, industry reports, and expert discussions — to identify the technologies and approaches that actually move the needle on home energy performance.
Our Component Scoring Methodology
We break down home energy performance into 6 key components, each scored individually and weighted to form your overall 0-100 score.
Envelope
Insulation, airtightness, and thermal bridging. Measures how well your home retains heat.
Heating
Efficiency of your heating system, including heat pumps and boilers.
Ventilation
Air quality and heat recovery systems like MVHR.
Water
Hot water efficiency and water heating systems.
Solar
On-site renewable generation from solar panels.
Storage/Grid
Battery storage, grid integration, and self-consumption optimization.
Real Benchmark Data
How does your home compare? Here are some real-world benchmarks on our 0-100 scale.
UK Average
42/100 - Typical existing homes with basic insulation and gas boilers.
Top 10%
78/100 - Well-insulated homes with efficient heating.
Passive House
88-95/100 - Ultra-efficient designs with MVHR and airtight envelopes.
Net Zero
95-100/100 - Fully renewable-powered homes with storage and optimization.
From Consumer to Prosumer
Every energy rating system in the world — EPC, DPE, NatHERS, HERS — shares the same blind spot: they only measure how efficiently a home consumes energy. EPC band A is the best a UK home can achieve. But EPC A is not the ceiling. It's just where the government stops measuring.
We exist to accelerate the decentralization of energy by turning every home from a passive consumer into an active prosumer node in a resilient grid. Our 0–100 score extends beyond EPC A because homes can be more than efficient, they can be prosumers: generating, storing, shifting load, and contributing to grid stability. That vision aligns with research such as EnergyNet, which frames homes as active nodes in a more decentralized energy system. Our research covers hundreds of technologies to map the full journey from energy consumer to active grid participant.
The EPC Ceiling Problem
EPC A is awarded at roughly 92+ SAP points. It recognises excellent insulation, an efficient heating system, and maybe some solar. What it doesn't capture: battery storage, vehicle-to-grid capability, demand response participation, or a home's role as a virtual power plant node. All of these are real, measurable, economically valuable — and invisible to the EPC.
On our scale, EPC A homes typically score 65–75. The top 25–35 points go to prosumer capabilities: solar generation above consumption, smart storage, V2G, and grid service participation — things the government standard was never designed to reward.
The 90–100 Band: Energy-Positive Homes
Homes scoring 90–100 are net energy exporters. Based on the Buildings as Batteries research (Hedar et al. 2023, Building Simulation), a fully optimised UK 3-bed semi with solar PV, battery storage, a smart heat pump, and V2G-capable EV can achieve:
- 6,000 kWh/year generated from rooftop solar
- 4,000 kWh/year gross consumption (after heat pump efficiency gains)
- −2,000 kWh/year net: the home is a grid asset, not a burden
- Thermal mass pre-charged during cheap/clean periods, reducing peak demand
- EV battery available for V2G services, adding 40–80 kWh of dispatchable storage
No EPC band exists for this home. Our score does — because the physics exists whether or not a government standard measures it.
The 100-Point Scale Through a Prosumer Lens
High-consumption home: poor insulation, fossil fuel heating, no renewables. Pure grid burden.
Average UK stock: partial improvements, possible gas condensing boiler, minimal renewables.
Well-retrofitted home: heat pump, good insulation, some solar. Approaching EPC A. Low consumer.
Net-zero home: energy balanced annually. Solar + battery covers consumption. EPC A ceiling.
Energy-positive prosumer: net exporter, grid-responsive, V2G-capable. A virtual power plant node. This is where EPC ends and the future begins.
Tiered Recommendations
Our recommendations are tiered to guide your journey:
- Essential: Core improvements for basic efficiency (insulation, efficient heating)
- Maximiser: Advanced prosumer tech like piezo flooring, V2G, and experimental innovations
This tiered approach makes the path from consumer to prosumer accessible and progressive.
Join Us
Whether you're a homeowner, energy assessor, data scientist, or policymaker — we want your input.
Start with Your Home
See how your home scores today. Track improvements over time. Be part of the community shaping the standard. Check out our guide to improving your rating.