Improving your Energy Performance Certificate (EPC) is no longer just a box-ticking exercise. With energy bills rising and Minimum Energy Efficiency Standards (MEES) tightening for landlords, securing a higher rating is essential for protecting the value of your property and ensuring compliance.

Whether you manage rental flats or houses and are stuck at an 'E' rating when you need a 'C' to rent your property, or you simply want a warmer home that is cheaper to run, this guide breaks down the actionable steps you need to take.

We will cover everything from cost-free "quick wins" to major structural investments. We address the specific challenges of both flats and houses to ensure you find the right strategy for your budget and property type.

Key insights

  • Prioritise insulation: Focus heavily on loft, wall, and floor insulation as your primary method for retaining heat and boosting your score.
  • Heating upgrades: Modernising your heating with efficient boilers or heat pumps is often the single most impactful change you can make.
  • Start small: Simple changes like LED lighting and heating controls are the best "low hanging fruit" for quick, cheap points.
  • Renewables: For top-tier 'A' or 'B' ratings, consider installing solar panels or battery storage.
  • Get a fresh assessment: If your EPC is old (they last 10 years) or predates your ownership, consider getting a new report before spending money. Assessors can sometimes make inaccurate assumptions.
  • Check the report: Your specific EPC certificate contains a tailored list of recommendations. Use it as your roadmap.

Understanding your EPC rating

What is an EPC and why does it matter?

An Energy Performance Certificate (EPC) rates the energy efficiency of your property on a scale from A (most efficient) to G (least efficient). It is a legal requirement whenever a property is built, sold, or rented. For landlords, it is particularly critical because under current Minimum Energy Efficiency Standards (MEES), you generally cannot grant a new tenancy for a property with a rating below 'E'. It is also widely anticipated that the minimum requirement will change to D or C soon, but the exact timing is unknown.

How to find your EPC rating

You can check your current rating online using the government's EPC register. By entering your postcode, you can view and download your certificate. This document highlights your current band and score. It also provides a tailored list of improvements which can serve as a roadmap for your renovations.

When to get a new EPC assessment

EPCs are valid for 10 years. If yours is a few years old , or if it was conducted before you bought the property, it is often worth commissioning a new assessment before investing in improvements. Assessors sometimes have to make assumptions about hidden elements like insulation or heating systems if they cannot access them. A fresh report ensures you are working with accurate data about the current performance of your property.

What causes a bad EPC rating?

Many older UK properties suffer from common issues that drag down their score. Uninsulated solid brick walls, single glazing, and old G-rated boilers are frequently flagged as "Very Poor" on certificates. Flats can face specific challenges if they rely on inefficient electric room heaters or lack control over communal heating systems, whereas houses often lose significant heat through uninsulated roofs and walls.

Quick wins to improve EPC cheaply

Switch to LED lighting

Replacing all halogen or incandescent bulbs with LEDs is one of the most cost-effective ways to gain points on your certificate instantly. LED bulbs use significantly less energy to produce the same amount of light, improving the efficiency of your fixed lighting. This is particularly beneficial for flats where leasehold restrictions might prevent you from undertaking more substantial structural upgrades.

Install heating controls

Fitting a room thermostat, a programmer, and Thermostatic Radiator Valves (TRVs) gives you far greater control over your energy usage. These controls will also save the resident money by ensuring only used rooms are heated, rather than wasting energy on empty spaces. For more advice on which upgrades offer the best returns, read our guide on smart renovation investment decisions.

Insulate your hot water cylinder

If your hot water tank is uninsulated, it loses heat rapidly, forcing your boiler to work harder. Adding a standard insulating jacket to your cylinder is cheap, easy to install, and effectively stops heat escaping. While this is often a lower priority than wall or roof insulation, it is a simple step that contributes to the overall efficiency of the system.

Property-specific strategies

Improving EPC ratings in flats

Owners of flats often face a unique set of challenges when trying to improve their energy efficiency. Leasehold agreements and building management rules can restrict external changes, such as upgrading windows, installing external wall insulation, or adding solar panels.

Because of these limitations, it is important to focus on the internal improvements within your control.

  • LED lighting: Replace all bulbs throughout the property.
  • Draft proofing: Seal gaps around windows and doors to retain heat.
  • Modern heating: Where there are old electric room heaters to modern storage heaters with integrated controls.
  • Heating controls: Install smart thermostats and TRVs where possible.
  • Internal insulation: Consider internal wall insulation if external changes are prohibited, provided it does not encroach significantly on living space.

It is worth noting that communal heating systems and the external fabric of the building including windows are typically outside an individual flat owner's control. In these cases, engaging with the freeholder or management company is often the only route to major upgrades.

Improving EPC ratings in houses

As a house owner, you generally have far greater flexibility to undertake comprehensive upgrades. You are not usually bound by the same leasehold restrictions as flat owners, allowing you to address the building's fabric and roof.

To move the dial on your EPC rating, consider these priority upgrades:

  • Loft insulation: Ensure you have a minimum depth of 270mm.
  • Wall insulation: Install cavity wall insulation or, for older properties, solid wall insulation.
  • Floor insulation: Insulate under suspended timber floors to reduce drafts.
  • Window upgrades: Replace single glazing with double or triple glazing.
  • Heating systems: Replace an old boiler with a condensing model or install a heat pump.
  • Renewables: Install solar PV or solar thermal systems to generate your own energy.

Listed buildings and conservation areas

Properties located in conservation areas or those that are Grade I or II listed may face strict planning controls that limit energy efficiency improvements. If an improvement would unacceptably alter the character or appearance of the building, or if you are refused necessary consent, you may qualify for an exemption from MEES requirements.

These exemptions must be formally registered on the PRS Exemptions Register and are valid for five years, after which they must be renewed.

However, owning a listed building or a flat within a listed building, does not mean you cannot improve its efficiency. Sympathetic improvements are often possible, such as installing internal insulation using breathable materials, fitting secondary glazing instead of replacing original windows, and upgrading to modern heating systems that do not impact the building's external appearance.

Significant upgrades to move from D to C

Loft insulation

Heat rises, and an uninsulated roof allows a significant portion of your home's warmth to escape. Topping up your loft insulation to the recommended depth of at least 270mm is widely considered one of the best value-for-money upgrades you can make. It is a relatively simple task that can have an immediate impact on your EPC score, helping to move a property out of a 'D' band.

Wall insulation

The type of wall insulation you need depends entirely on the construction of your property.

  • Cavity walls: If your home was built after the 1920s, it likely has cavity walls. Injecting insulation into this cavity is usually straightforward and cost-effective.
  • Solid walls: Older properties typically have solid brick walls. Insulating these is more expensive and disruptive, involving either internal dry lining or external cladding. However, it is highly effective for older homes and can transform their thermal efficiency.

Floor insulation (houses)

Many older houses have suspended timber floors which can be a major source of draughts. Lifting the floorboards to install insulation between the joists creates a sealed thermal envelope. This not only improves your EPC rating but also makes the room feel noticeably warmer underfoot.

Upgrade your windows

Replacing windows with modern double or triple glazing significantly improves heat retention and reduces noise pollution. While this is a substantial investment, it is a key factor in improving both the energy efficiency and the overall appeal of a home. For further insight into how such improvements affect property prices, read our guide on what adds value to a house.

Owners of leasehold flats should verify whether they are permitted to replace windows. 

Modernise your boiler or heating system

Your heating system is arguably the most influential factor in your EPC rating. If you have an old, non-condensing boiler (often rated 'G'), replacing it with a modern A-rated condensing model can drastically improve your score.

Alternatively, you might consider transitioning to a low-carbon option such as an air source heat pump. The right choice depends on the size and type of your property, as heat pumps require high levels of insulation to operate efficiently.

High-level upgrades and renewables

Solar photovoltaics (PV)

Generating your own electricity is a major step toward achieving an 'A' or 'B' rating and future-proofing your home against rising energy costs. Solar PV panels convert sunlight into electricity, which you can use to power your appliances or charge an electric vehicle. While this technology is becoming standard for modern houses, installation on flats typically requires the freeholder's permission, as the roof is usually communal property.

Solar thermal

Unlike PV panels which generate electricity, solar thermal systems use energy from the sun to heat your water. This reduces the demand on your boiler and lowers your gas or electricity usage. While effective, it is important to weigh the installation cost against the potential savings. For further context on which renovations offer the best returns, read our guide on home improvements that don't add value.

Specific advice for period properties

Renovating Victorian and period homes

Owners of period properties face a delicate balancing act between preserving heritage and improving efficiency. Victorian homes often have solid brick walls rather than cavity walls, meaning standard insulation methods are not suitable. Applying impermeable insulation to these walls can trap moisture and cause dampness.

Often, the most appropriate solution is internal wall insulation using breathable materials that allow the building fabric to function naturally. It is also vital to check if your property is in a conservation area, as this may limit changes to the external appearance, such as replacing windows. For more on managing older homes, see our article on what to fix and what not to fix when selling a house.

Professional support

Hamptons Design & Refurbishment Service

Improving your EPC rating can be a complex process involving contractors, regulations, and technical decisions. For anyone planning a major renovation, our hDesign service offers expert guidance. We can help you identify the most cost-effective improvements for your specific property type and manage the project from start to finish, ensuring you achieve the rating you need without unnecessary stress. We have multiple third party tried-and-tested suppliers who reliably complete projects in a timely fashion.

Conclusion

Improving your EPC rating requires balancing low-cost "quick wins" with longer-term investment. We recommend prioritising cheaper measures like lighting and insulation first. If your certificate is dated, commission a fresh assessment before spending heavily.

For flat owners, the focus must be on internal upgrades; for house owners, it is about improving the building's fabric. To discuss cost-effective improvements or to book a valuation, contact our estate agents today.