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Retrofit

What is Retrofit?

Retrofitting refers to the process of improving the energy efficiency and sustainability of existing buildings, reducing their impact on the environment. In undertaking these works, it means that homes can be more comfortable to live in, and generally more cost-effective to run.

These works typically include additional insulation to the loft and walls, as well as improved ventilation. However, each property may experience a different approach depending on its structure, previous installations, as well as factors such as government grant funding.

Why is Retrofitting Important?

Carbon Emissions from UK Homes
Around 22% of carbon dioxide emissions in the UK comes from our homes, which consequently contributes to global warming. To reach the UK’s net zero emissions target by 2050, it is essential to upgrade our houses, allowing us to reduce the effects of climate change faced in this country, such as flooding, heatwaves, and storms.  

Energy Inefficiency and Living Costs
Houses that are not energy-efficient often have the highest living cost due to the homes not being able to retain heat effectively, and therefore requires more money spent on fuel to get the homes to a comfortable temperature. When households are living in a property that is considered as energy-inefficient and, after paying for energy, they are left with an income below the official poverty line, they are classed as being in “fuel poverty”. Latest estimates suggest that around 11% of households in England are classed as fuel poor, demonstrating the important need to retrofit our houses.

Economic Benefits
Retrofitting can also be important for the economy through the employment of local businesses alongside the increased need for new skilled jobs (such as solar installers and heat engineers).  

Government Funding for Retrofit Works
The retrofit works being carried out on our social housing properties are supported through the Warm Homes: Social Housing Fund. This government-backed funding helps councils and housing providers improve the energy efficiency of homes by installing measures such as insulation, ventilation upgrades, and low-carbon heating systems.
This funding allows us to carry out these upgrades at no cost to tenants, helping improve the overall quality of homes, reduce energy bills, and support national efforts to lower carbon emissions.

What Do Retrofit Works Involve?
Retrofit works involve a combination of improvements designed to help a home use less energy, stay warmer for longer, and maintain healthy air quality. Rather than focusing on one single upgrade, retrofitting looks at the property to identify where heat is being lost and how moisture is being managed. This means each home receives a tailored package of measures that work together to improve comfort, reduce running costs, and support long-term sustainability.

Common Retrofit Improvements

The specific measures required will vary from home to home, based on the building’s structure and existing installations. Here is an overview of the measures most frequently used:

  • Loft insulation: A layer of material installed in the roof space that reduces heat loss in the winter and heat gain in the summer. Current guidance recommends approximately 300mm of loft insulation to achieve effective thermal performance.
  • Cavity Wall Insulation (CWI): Beads or fibres are injected into the gap between the house’s inner and outer walls to stop heat loss. Before CWI installation, holes are typically drilled in a specific pattern on the exterior walls of the property to allow the insulation to be injected.
  • External Wall Insulation (EWI): An external wall system where insulating materials (such as mineral wool or polystyrene) are fixed to the outside of a property’s walls and then covered with a protective render or cladding.
    Internal Wall Insulation (IWI): The installation of an insulating material on the internal face of the external wall.
  • Air Source Heat Pump (ASHP): A low-carbon, electric heating system that extracts heat from the outside air to provide space heating and hot water. ASHP are typically 3-4 times more efficient than traditional boilers, providing heating bill savings from £100 to over £1,500, depending on the system replaced and energy usage.
  • Solar Photovoltaics (PV): PVs are a collection of panels, typically installed on the roof, that converts sunlight directly into electricity.
  • Ventilation: Everyday activities in our homes generates moisture, such as from cooking and showering. If the moisture isn’t properly removed through effective ventilation, it can build up and increase the chances of damp and mould developing. Mechanical ventilation usually involves fitting extractor fans in kitchens and bathrooms, supported using windows that have built-in background vents to help keep air flowing. Good ventilation becomes even more important after installing heat-insulation measures, as improved insulation makes homes more airtight, meaning moisture has fewer places to escape.
  • Door undercuts: A 10mm to 25mm gap between the door bottom and floor is cut to allow air transfer and improved ventilation, important for reducing damp and mould after heat-insulation measures have been implemented.
    Low energy lightbulbs: Light bulbs designed to deliver high brightness while using very little electricity, typically consuming 80-90% less energy and lasting far longer than traditional bulbs.
  • Heating controls: Heating controls, specifically Thermostatic Radiator Valves (TRVs), can allow individuals to regulate the temperature of the radiators individually in each room and therefore can assist in reducing heating bills. 

Understanding the Retrofit Works Stage

Asbestos Survey Requirements
If we find that your property doesn’t have a recent or complete asbestos report, you will be contacted to organise a new survey.

Retrofit Assessment Before Works Begin
Before any improvement works begin, you will also be contacted by one of our contractors to arrange a retrofit assessment at your property. This assessment is a requirement for government-funded retrofit programmes and help us to identify which energy-efficiency improvements are suitable for your home and eligible for funding. 

Access and Property Preparation
Please ensure that your property is accessible so these surveys and works can proceed. A clear perimeter around your property is required for activities such as erecting scaffolding and carrying out any works to the external walls. This includes removing or relocating any foliage, garden items, vehicles, or other obstacles where necessary.

Dust, Noise and Disruption
Some parts of the works may produce dust and noise. While every effort will be made to reduce this, some disruption may be unavoidable. Contractors will help minimise any impact by sealing internal gaps before CWI works and by informing you in advance if loud noise is expected.

Let Us Know About Vulnerable Occupants
If anyone in the property may be particularly affected by dust or noise, please let a liaison officer know in advance – either through the contracted company or directly through Stroud District Council.