Guidance for home energy improvements

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Retrofitting your home is a great way to make it greener, more energy efficient, warmer, and cheaper to run.

In this section:

What is retrofitting

Retrofitting is when you replace or upgrade your home with new materials, products or technology.

The aim of retrofit is to make homes:

  • greener
  • more energy efficient
  • warmer
  • cheaper to run

This could involve anything from switching to LED light bulbs, improving insulation to installing solar panels.

Depending on the type and age of your house, your retrofitting needs will vary. The most common improvements include:

  • Standard upgrades: Switching to LED light bulbs, upgrading windows, and improving door seals
  • Intermediate upgrades: Insulating walls, floors, and roofs, and improving ventilation
  • Enhanced upgrades: Adding thicker insulation, installing solar panels, or switching to low-carbon heating

You can retrofit your home step by step or do everything at once. It's best to combine enhanced upgrades with any other extensions or building works.

How to get started

You can start small with things like fixing draughts or adding insulation, and then move on to bigger improvements like solar panels or heat pumps.

There are three key areas of retrofitting:

  1. Energy conservation: Use less energy by making simple changes like draught-proofing and using heating controls efficiently.
  2. Energy efficiency: Improve your home’s insulation, glazing, and other structural elements to keep the heat in.
  3. Renewable energy: Once you’ve reduced energy use and improved efficiency, consider switching to renewable energy like solar power or heat pumps.

You can retrofit your home step by step or do everything at once. It's best to combine enhanced upgrades with any other extensions or building works.

Understand your home

  • Check if you have a valid energy performance certificate (EPC) for your property, which lists energy efficiency improvements
  • Request a smart meter to keep track of your energy use 
  • Use a thermal imaging camera to identify areas of heat loss. If you're an Octopus Energy customer, you can borrow a camera for free

Get tailored advice

Sources of heat loss

Understanding where your home loses heat is key to knowing what to fix. The main sources of heat loss are:

  • Walls: Poor insulation can cause 35-45% of heat loss
  • Roof: Up to 20% of heat can escape through an uninsulated roof
  • Floor: Older homes with uninsulated floors can lose up to 10% of heat
  • Windows and doors: Thrugh draughts from windows and doors are noticeable, they account for less heat loss when compared to walls and roofs

Get the right permissions

Before you start work,  find out if you need planning permission, or building regulations approval, especially if you live in a listed building or conservation area. Check pre-application advice

If you're a landlord, ensure your property meets Minimum Energy Efficiency Standards (EPC Band E or above). This is part of our Housing Strategy 2023-28

Even if work to your home does not need approval you should: 

  • think about the impact of measures on the heritage value of your home
  • consider whether the measure is reversible

Finding the right contractor

Make sure your contractors are: 

  1. Microgeneration Certification Scheme (MCS) accredited. If installing low carbon heating systems like heat pumps.

  2. Publicly Available Specification 2035 (PAS 2035) certified. for energy efficiency measures funded by public schemes

  3. TrustMark registered. This Government backed scheme ensures quality workmanship

Things to watch out for when retrofitting

Some retrofit measures may increase the risk of problems like:

  • damp
  • moisture build up
  • poor ventilation

To avoid these issues, start with lower risk measures like draught-proofing, and see if they improve comfort and reduce energy costs before moving on to bigger projects like solid wall insulation.

Lower-risk measures are usually more affordable and easier to reverse if needed.