When it comes to achieving a high Energy Performance Certificate (EPC) rating, few factors are as critical as your property’s insulation and building fabric. The way your walls, floors, roofs, windows, and doors are constructed — and how well they retain heat — has a major impact on how energy-efficient your home truly is.
At EPCrate.co.uk, our qualified EPC assessors evaluate these structural details carefully to determine how your home performs against modern efficiency standards.
What Is Building Fabric?
The building fabric refers to all the fixed elements of a property that form its thermal envelope — such as:
External walls
Floors and roofs
Windows and glazing systems
External doors and draught barriers
A well-insulated and airtight building fabric reduces heat loss, meaning your property requires less energy to stay warm, directly improving your EPC score.
Why Insulation Matters in EPC Assessments
EPC ratings measure how efficiently your home uses and retains energy. During an assessment, inspectors look at the type, thickness, and condition of insulation in key areas:
🧱 Wall Insulation
Cavity wall insulation can cut heat loss by up to 35%, while solid wall insulation can raise an EPC band by one or more levels — especially in older homes.
🏠 Roof and Loft Insulation
Since up to 25% of heat escapes through the roof, proper loft insulation is one of the quickest ways to improve an EPC rating.
🪟 Windows and Glazing
Double or triple glazing reduces heat transfer and minimises draughts, improving thermal comfort and EPC outcomes.
🚪 Floor Insulation and Draught Proofing
Underfloor insulation and sealed skirting help maintain stable indoor temperatures, reducing heating demands and enhancing efficiency.
To book a professional EPC inspection that evaluates these features, visit our EPC booking page today.
How Building Fabric Is Scored in an EPC Assessment
During an EPC assessment, the assessor records:
The construction type of the building
Whether insulation is present and accessible
The U-values (heat transfer rates) of walls, roofs, and floors
Window and door specifications
Any thermal bridging or air leakage risks
This data feeds into the Standard Assessment Procedure (SAP), which calculates how much energy your property consumes — determining your final EPC grade.
Upgrading Your Insulation: The Benefits
Improving your property’s insulation delivers both environmental and financial advantages:
Lower energy bills
Greater indoor comfort
Reduced carbon emissions
Higher resale or rental value
Easier compliance with upcoming regulations such as the Future Homes Standard
If you’re unsure where to begin, speak with one of our energy assessors for a tailored upgrade plan.
How to Improve Your EPC Score Through Building Fabric
Upgrade wall and roof insulation to meet or exceed 270 mm loft depth.
Replace single glazing with A-rated double glazing.
Seal gaps and improve airtightness around doors and windows.
Consider external or internal solid wall insulation for older homes.
Book a follow-up EPC reassessment after improvements.
Book Your EPC Assessment with EPCrate
At EPCrate.co.uk, we specialise in accurate, compliant, and fast EPC assessments across London and beyond. Whether you’re selling, renting, or improving your property, our experts will guide you on how insulation and building fabric upgrades can boost your EPC rating efficiently.
📞 Get in Touch
We make EPCs simple, transparent, and stress-free.
Reach out to our team to discuss your property, request a quote, or schedule an assessment.
📧 Email: info@epcrate.co.uk
📞 Phone: 020 34884142
