What is Retrofit? A Complete Guide to Retrofitting in the UK

Retrofitting is quickly becoming one of the most important topics in the UK’s housing and construction sectors. With rising energy costs, stricter environmental regulations, and a national push towards reducing carbon emissions, retrofit is no longer just an option—it’s a necessity.

What Does Retrofit Mean?

Retrofit refers to the process of upgrading existing buildings to improve their energy efficiency, comfort, and overall performance. This can include anything from installing better insulation and upgrading windows to implementing modern heating systems and renewable energy solutions.

Unlike new builds, which are designed with the latest energy efficiency standards, many older properties in the UK were built with outdated materials and techniques. Retrofitting allows us to bring these homes up to modern standards without the need for demolition and rebuilding.

Why is Retrofit Important in the UK?

1. The UK’s Ageing Housing Stock

The UK has one of the oldest housing stocks in Europe. According to the UK Government, around 36% of homes were built before 1945, and 80% of the homes that will exist in 2050 have already been built. This means that improving energy efficiency in existing homes is critical to meeting the country’s carbon reduction targets.

2. Reducing Energy Bills

With energy prices increasing dramatically in recent years, many households struggle to keep up with their heating costs. The UK’s poorly insulated homes mean that up to 35% of heat is lost through walls and 25% through roofs. Retrofitting with modern insulation, double or triple glazing, and efficient heating systems can cut energy bills by £1,000 per year or more for many homes.

3. Meeting Net Zero Targets

The UK has committed to reaching net zero carbon emissions by 2050. Since homes account for around 20% of the UK’s carbon emissions, large-scale retrofit projects are essential to achieving this goal.

4. Improving Health and Wellbeing

Cold, damp homes are linked to respiratory illnesses, poor mental health, and increased risks of cardiovascular disease. The NHS spends an estimated £1.4 billion per year treating illnesses related to poor-quality housing. By improving insulation, ventilation, and heating systems, retrofitting can significantly enhance public health while reducing pressure on healthcare services.

What Are the Key Retrofit Measures?

Insulation Upgrades – Installing wall, roof, and floor insulation to reduce heat loss.

Window and Door Improvements – Replacing single glazing with double or triple glazing to improve thermal efficiency.

Heating System Upgrades – Switching to low-carbon heating solutions such as heat pumps or district heating.

Renewable Energy Installation – Adding solar panels or battery storage to reduce reliance on fossil fuels.

Ventilation Enhancements – Ensuring good indoor air quality by installing mechanical ventilation with heat recovery (MVHR) systems.

The Challenges of Retrofit

While retrofit offers many benefits, it also comes with challenges:

Cost – Deep retrofit projects can be expensive, but government grants and incentives (such as the ECO4 scheme) help offset costs.

Disruption – Retrofitting a home can be disruptive, especially for homeowners living on-site during renovations.

Skills Shortage – There is a growing need for skilled professionals in the retrofit industry to meet increasing demand.

UK Government Policies Encouraging Retrofit

The UK Government has introduced several policies to drive retrofit adoption and improve energy efficiency across the country.

1. Great British Insulation Scheme (GBIS)

Launched in July 2023, GBIS aims to enhance energy efficiency in homes across Great Britain. The scheme focuses on providing insulation measures, particularly targeting households in fuel poverty. With a budget of £1 billion over three years, it seeks to treat approximately 315,000 homes, helping residents save an average of £300-£400 annually on energy bills.

2. Building Regulations and the Merton Rule

The UK's Building Regulations have increasingly focused on energy efficiency. The Merton Rule requires new commercial buildings over 1,000 square metres to generate at least 10% of their energy needs through on-site renewable energy. This policy has influenced planning guidance nationwide, promoting the integration of renewable energy in retrofit projects as well.

3. National Retrofit Strategy

Advocated by organisations such as the UK Green Building Council (UKGBC), the National Retrofit Strategy calls for a structured approach to upgrading the UK’s housing stock. It highlights the need to retrofit 29 million homes by 2050, starting with 19 million homes that currently fall below EPC ‘C’ ratings. The strategy aims to cut carbon emissions, reduce fuel poverty, and stimulate job creation in the green sector.

Retrofit Grants and Support in the UK

To encourage more homeowners and landlords to undertake retrofit projects, the UK Government has introduced several schemes:

Energy Company Obligation (ECO4) – A scheme that funds energy efficiency improvements for low-income households.

Home Upgrade Grant (HUG) – Support for homes that are off the gas grid to improve their efficiency.

Social Housing Decarbonisation Fund – Funding for social housing providers to upgrade properties and reduce emissions.

Why Retrofit Matters for the Future

Retrofit isn’t just about reducing emissions—it’s about making homes more comfortable, affordable, and healthier places to live. With rising energy costs, an urgent need to cut carbon emissions, and a growing awareness of sustainability, retrofit will play a central role in the UK’s housing future.

At Target Green, we specialise in delivering high-quality retrofit solutions that improve energy efficiency, cut bills, and future-proof properties. Whether you're a council, housing association, or private landlord, investing in retrofit now will pay dividends in the years to come.

If you’re interested in learning more about retrofit solutions, get in touch with Target Green today.