Night storage heaters, once promoted as an economical heating solution during off-peak electricity hours, are now considered outdated in the context of modern energy efficiency standards. Similarly, homes with other obsolete heating technologies—such as electric panel heaters, warm air systems, or gravity-fed hot water systems—often struggle to achieve favourable Energy Performance Certificate (EPC) ratings.
In this article, we explore how EPC assessments treat these legacy heating systems and why they can be a significant obstacle in improving a property’s energy efficiency score.
What Are Night Storage Heaters?
Night storage heaters are electric heaters designed to store thermal energy during off-peak electricity tariff periods (typically overnight) and release the heat during the day. While they were once cost-effective, advancements in heating technology have exposed their inefficiencies:
Lack of precise temperature control.
Significant heat loss if not well-insulated.
Difficulty managing comfort during variable weather conditions.
How EPC Assessments Penalize Night Storage Heaters & Obsolete Heating Systems
1. Low Assumed System Efficiency
EPC software assigns standard efficiency figures to storage heaters that are significantly lower than modern alternatives like heat pumps or high-efficiency gas boilers. Even more advanced storage heaters (with fan assistance or thermostatic control) often receive modest improvements in assessment models.
2. Primary Heating System Assumptions
If storage heaters or panel heaters are the main heating system, EPC models apply default efficiencies and may assume higher-than-actual energy consumption, especially in poorly insulated properties.
3. Lack of Zoned Heating Recognition
Obsolete systems are often incapable of zoned heating (heating specific rooms only when needed), which leads EPC software to assume the entire home is being heated inefficiently.
4. Inflexibility in EPC Software for Modern Usage Patterns
While some homeowners supplement storage heaters with secondary heating (like infrared panels or portable devices), EPC assessments may still calculate energy demands based solely on the outdated primary system.
5. Secondary Heating Penalties
If portable electric heaters or open fireplaces are present, the EPC software assumes a significant level of usage, which further impacts the overall efficiency score.
The EPC Reality Gap for Legacy Heating Systems
In practice, many homeowners with storage heaters adapt their usage to minimize waste. However, EPC assessments are model-driven and apply rigid assumptions that fail to account for such behavior, resulting in downgraded ratings.
How to Improve EPC Ratings for Properties with Obsolete Heating Systems
Upgrade to Modern Heating Solutions: Replacing storage heaters with energy-efficient heat pumps, modern electric radiators, or gas central heating can dramatically improve EPC outcomes.
Install Smart Controls: Where replacement isn’t feasible, installing smart thermostats and controls can help mitigate penalties, though documentation is essential.
Document Secondary Heating Minimization: Clarify the role of secondary heating sources to ensure they aren’t incorrectly weighted in the energy calculation.
Improve Insulation & Airtightness: Enhancing fabric efficiency can compensate for outdated heating inefficiencies.
Choose Assessors Experienced with Older Systems: Knowledgeable EPC assessors can better navigate input options to reflect the property’s real-world usage.
EPCrate: Helping Legacy Heating Homes Navigate EPC Challenges
At EPCrate, we specialize in EPC assessments for homes with legacy heating systems, ensuring that inefficiencies are fairly documented and upgrade pathways are clearly outlined. Our EPC services are tailored to address properties using night storage heaters and similar technologies.
Explore our pricing and schedule a professional assessment via our online booking system.
Book an EPC Assessment for Homes with Legacy Heating Systems
Ensure your property’s energy efficiency potential is assessed accurately. Contact EPCrate to arrange an expert EPC assessment tailored for homes with storage heaters and obsolete heating technologies.
