A staggering 95% of landlords admit they do not know the current numerical score underpinning their property’s Energy Performance Certificate (EPC) rating.
Yet, understanding this hidden points system could be the key to unlocking simple and cost-effective energy upgrades, according to new research by energy efficiency platform epIMS.
EPC ratings, which range from A (most efficient) to G (least efficient), rely on a numerical score – known as Standard Assessment Procedure (SAP) points – to determine their grade.
For instance, a property needs 92-100 SAP points to achieve an A rating, 81-91 points for a B, and 69-80 points for a C. Crucially, this means that a property rated D could be just one point away from upgrading to a C with the right improvement.
LACK OF AWARENESS
Despite this potential, only 5% of landlords are aware of their property’s numerical score. This lack of awareness leaves many missing out on easy wins to boost their EPC rating, a growing priority amid tighter energy efficiency regulations.
SMALL CHANGES, BIG GAINS
epIMS’ research reveals how minor improvements can yield meaningful boosts to EPC scores. For example:
- Adding hot water cylinder insulation: +1.7 points
- Installing a hot water cylinder thermostat: +2.4 points
- Switching to low-energy lighting: +1.1 points
These straightforward upgrades can make all the difference for properties on the cusp of a higher rating.
STRATEGIC CHOICES
While sustainable heating systems like biomass boilers are often championed for their eco-credentials, they don’t always provide the best EPC gains. A standard condensing gas boiler, for instance, adds an average of +23 points, compared to just +12 points for a biomass boiler. For landlords focused on EPC ratings, this difference is significant.
Renewable energy installations can also make an impact, with solar panels adding an average of +9.91 points and wind turbines contributing +6.39 points.
INSULATION IMPACT
Improved insulation remains one of the most effective ways to boost an EPC score. However, not all insulation measures are created equal.
- Double glazing: +3.3 points
- Loft insulation: +4.9 points
- Wall insulation: +7.7 points
- Room-in-roof insulation: +9.91 points
Room-in-roof insulation stands out as the most impactful, providing landlords with a cost-effective route to significant energy efficiency gains.
MINIMUM C RATING

Craig Cooper, Chief Operating Officer of epIMS, says: “The push for EPC improvements is on and by 2030, landlords will be expected to hold a minimum C rating.
“Whilst the estimated cost of achieving a C rating comes in at around £8,000, many landlords may find that they pour a far greater amount of money into their property without seeing any real improvement to their EPC score.
“That’s because the vast majority remain unaware that an EPC rating is based on a points system and understanding this is the first step to making home improvements that will actually make a difference when it comes to improving an EPC score.”
ADVANCE ALGORITHMS
“Of course, this knowledge is only useful if you know what score your property currently holds and exactly how many points you’re going to get from each particular efficiency upgrade available.
“That’s why we’ve developed epIMS and our platform utilises advanced algorithms and AI to calculate exactly how a property can best reach the next EPC rating band.”