Domestic Energy Performance Certificates (EPC)

How is the EPC Rating Calculated?

The core rating on a domestic EPC is primarily driven by the calculated cost to run the building per square metre. The underlying methodology uses standardised, regulated fuel price structures that map out the relationships between different energy sources (such as mains gas, heating oil, and grid electricity). This gives prospective buyers or tenants an standardised, objective preview of their projected utility bills.

Key Architectural and Structural Features

Beyond the overall headline score, an EPC evaluates individual structural and mechanical elements of a home, rating each from Very Poor to Very Good:

• Thermal Envelope: Walls, floors, and roofs. High-performance, insulated building elements drastically reduce heat loss. While thick, traditional South West construction materials like cob offer fair native thermal properties, uninsulated solid stone walls transmit heat rapidly and require careful assessment.

• Glazing Performance: Modern double or triple glazing significantly elevates a property's rating compared to legacy single-glazed windows.

• Space & Water Heating: Systems with lower calculated operational costs yield much higher scores. While high-efficiency gas boilers perform reliably, and modern high heat-retention storage heaters offer a practical off-peak electric alternative, simple direct-acting electric panel heaters carry high operational costs and will suppress a domestic EPC rating.

Whether you are a homeowner preparing to sell, a landlord keeping up with changing rental compliance standards, or a developer completing a new residential project, Up Energy provides swift, accredited domestic assessments across the South West.