Energy Performance Certificates (EPCs) are an essential part of property management, buying, and renting in the UK. Yet many homeowners make common mistakes that not only reduce their EPC rating but also lead to higher energy bills and costly future upgrades.

Understanding these pitfalls can save you money and stress, while ensuring your property is energy-efficient and compliant. If you need a professional EPC assessment, you can book with EPCrate here:
👉 Book Your EPC Assessment

1. Ignoring Insulation Issues

One of the biggest EPC killers is poor or missing insulation. Many homeowners:

  • Assume older insulation is adequate

  • Forget loft, wall, or floor insulation

  • Don’t document insulation upgrades

Why it costs money:
Homes with insufficient insulation lose heat quickly, forcing heating systems to work harder. This drives up energy bills and lowers EPC ratings.

How to fix it:

  • Top up loft insulation to 270mm

  • Add cavity or solid wall insulation

  • Keep receipts for all improvements

Learn more about EPC insulation guidance here: EPC Services

2. Outdated Heating Systems

Old boilers or inefficient heating setups are a major contributor to poor EPC scores. Common mistakes include:

  • Keeping non-condensing boilers

  • No thermostatic radiator valves (TRVs)

  • Missing smart controls or timers

Financial impact:
Inefficient heating increases energy bills dramatically, costing hundreds of pounds a year.

Solution:
Upgrade to a modern condensing boiler and add programmable controls. If unsure, get an assessment from EPCrate.

3. Neglecting Windows and Doors

Single-glazed windows, drafty doors, and poorly sealed frames are often overlooked. Even if visually fine, assessors flag:

  • Air leaks around doors and frames

  • Non-double-glazed windows

  • Draughty loft hatches

Cost consequence:
Heat escapes, increasing energy usage and reducing EPC score.

Quick fix:

  • Install double glazing where possible

  • Seal gaps and add draught excluders

4. Forgetting Hot Water Efficiency

Many homeowners ignore their hot water systems. EPC assessors check:

  • Cylinder insulation

  • Pipe insulation

  • Efficiency of immersion heaters

Financial impact:
Uninsulated tanks and pipes waste energy, increasing bills by hundreds annually.

Solution:
Add pipe lagging and cylinder jackets. For professional guidance, check EPCrate Pricing.

5. Overlooking Small Energy-Efficiency Upgrades

Even minor upgrades are often skipped:

  • Switching to LED lighting

  • Installing radiator reflector panels

  • Using smart thermostats

These small changes might not seem significant but EPC software rewards them, and they reduce energy usage immediately.

6. Doing Upgrades in the Wrong Order

Many homeowners invest in expensive upgrades first, like solar panels or premium windows, while neglecting basics like insulation or heating.

Why it fails:
EPC ratings prioritize high-impact improvements first. A new boiler or wall insulation can often raise your score more than solar panels alone.

Tip:
Start with insulation and heating improvements before moving to renewable energy.

7. Lack of Documentation

Even if you’ve made all the right improvements, missing evidence can lower your EPC. Assessors may assume the upgrades aren’t installed if there’s no proof.

What to keep:

  • Receipts for insulation, windows, and heating upgrades

  • Certificates for renewable energy installations

  • Manufacturer documentation

8. Ignoring EPC Recommendations

Every EPC comes with a list of recommended improvements. Many homeowners ignore this roadmap, thinking small changes are unnecessary.

Financial impact:
Ignoring recommendations often leads to higher energy bills, costly retrofits later, and lower resale value.

Solution:
Follow the EPC’s suggested improvements in order of impact. For professional advice, see About EPCrate.

9. Misunderstanding Seasonal Efficiency

Some homeowners fail to account for seasonal energy use. Cold winters can expose insulation gaps, heating inefficiencies, and drafts that were invisible during warmer months.

Impact:
Lower EPC scores and higher energy bills during peak seasons.

Tip:
Check your property during colder months or have an assessor evaluate for seasonal heat loss.

10. DIY Fixes Without Professional Oversight

While DIY upgrades can help, incorrect installation can backfire, reducing efficiency or even damaging systems. Examples:

  • Poorly fitted insulation

  • Incorrect boiler installation

  • Sealing windows incorrectly

Cost:
Mistakes can require professional correction, adding hundreds to upgrade costs.

Solution:
Use accredited installers or consult EPC professionals like EPCrate:
👉 Contact EPC Experts

Final Thoughts

Avoiding these common EPC mistakes can save homeowners hundreds in energy bills, upgrade costs, and compliance issues. Focus on:

  • Insulation

  • Heating efficiency

  • Hot water improvements

  • Draft-proofing and small energy-efficiency measures

A strategic approach ensures your home achieves a higher EPC score and lowers long-term energy costs.

Email :info@epcrate.co.uk

Phone:020 34884142