Whether you’re a homeowner, landlord, or buyer, your property’s EPC (Energy Performance Certificate) score matters more than you think. It affects property value, rental eligibility, mortgage access, and energy costs. But thanks to outdated advice and online hearsay, many property owners unknowingly fall for EPC myths—making costly decisions as a result.

Let’s debunk the 5 most common EPC myths that could be draining your wallet.

Myth 1: “A New Boiler Guarantees a High EPC Score”

Reality:
While a new boiler is more efficient than an old one, it won’t necessarily push your EPC rating up significantly on its own.

  • The EPC algorithm considers heating controls, insulation, and fuel type alongside the boiler itself.

  • A top-tier boiler with poor loft insulation can still result in a mediocre rating.

✅ Smart Move: Upgrade heating controls (e.g., thermostatic radiator valves, smart thermostats) and ensure your home is well-insulated before investing in a boiler alone.

Myth 2: “Double Glazing Has the Biggest Impact on EPC Scores”

Reality:
Double glazing is helpful—but its impact is often overestimated.

  • Windows account for a smaller proportion of heat loss compared to walls and roofs.

  • If your loft or cavity walls are uninsulated, those will weigh more heavily on your EPC rating than single-glazed windows.

✅ Smart Move: Prioritise loft and wall insulation first. EPC assessors assign higher value to those upgrades.

Myth 3: “EPC Scores Are Based on Your Energy Bills”

Reality:
The EPC doesn’t measure how much energy you actually use—it models how much you would use based on standard assumptions.

  • EPCs don’t factor in occupant behaviour.

  • You could use very little energy and still have a poor EPC rating.

✅ Smart Move: Improve your property’s fabric efficiency (walls, roof, windows, doors) and heating systems, not just your personal energy habits.

Myth 4: “Solar Panels Automatically Give You an ‘A’ Rating”

Reality:
Solar PV systems help—but they don’t guarantee top marks.

  • If the rest of the home is poorly insulated or uses outdated heating systems, solar won’t be enough.

  • EPC ratings are weighted more heavily toward heating efficiency and insulation than electricity generation.

✅ Smart Move: Combine solar with insulation upgrades and a high-efficiency heating system for the best EPC results.

Myth 5: “All Homes of the Same Type Get Similar EPC Scores”

Reality:
Two identical properties on the same street can have wildly different scores depending on:

  • Renovations

  • Heating systems

  • Insulation quality

  • Ventilation setup

  • The documentation provided to the assessor

✅ Smart Move: Ensure you document every upgrade and provide all certificates. EPC scores are partly based on evidence—not just observation.

Final Word: Don’t Let EPC Myths Cost You

Understanding how EPCs really work can help you prioritise upgrades that matter, avoid unnecessary expenses, and improve both comfort and compliance.

📌 Whether you’re preparing to rent, sell, or improve your home’s efficiency, start by separating fact from fiction—and make sure your EPC strategy is driven by data, not myths.

Need an EPC in London or urgent advice?
Book your EPC assessment now with a qualified local assessor.

📍 Final Takeaway

The EPC graph is just the beginning. When you know how to read between the lines, your report becomes more than a score—it becomes a blueprint for saving energy, reducing emissions, and increasing property value.

Ready to unlock the full story of your EPC?
📅 Book your expert EPC assessment today at EPCrate.co.uk.