The 'ins' and 'outs' of retrofit

With climate change a growing concern, retrofitting our existing buildings has become increasingly crucial. 

Home retrofit is the process of upgrading a building to improve its energy efficiency, sustainability, and overall performance. It's a vital step towards achieving net zero emissions, as approximately 18% of our annual national CO2 emissions come from existing homes, according to this Government report.

The UK has one of the oldest and leakiest housing stocks in western Europe, possibly in the world. Yet 80% of homes that are lived in today will still be inhabited in 2050. The UKGBC estimates that half of UK homes have uninsulated walls and 29million homes will need retrofitting before 2050.

While the challenge of retrofitting millions of homes is no small feat, the potential benefits are immense. Retrofitting can significantly reduce fuel bills, help to improve health and well-being, and enhance comfort. 

 

Fabric-first approach

So, where do you start?

Retrofitting can be a complex process, but the first step to consider is a holistic approach that considers the building's fabric, services, renewables, and the people who live there. A fabric-first approach is recommended, focusing on improving the building envelope's energy efficiency before adding renewable technologies.

To achieve this means selecting appropriate insulation, ventilation, and airtightness. This approach can reduce energy costs, improve temperature control and result in lower running costs and a reduced chance of condensation and mould.

Adequate insulation and ventilation are essential for thermal efficiency and comfort. Careful detailing is necessary to prevent thermal bridges, which can lead to heat loss.

When it comes to airtightness, a well-sealed building minimises heat and moisture loss, reducing the risk of condensation and mould growth. Effective moisture management is vital to prevent mould and other issues. This includes addressing sources like penetrating or rising damp and ensuring proper ventilation.

A holistic approach that considers insulation, ventilation, and airtightness can help avoid costly remedial work in the future. 

 

Retrofit measures to consider

  • Install insulation, such as cavity wall or loft insulation.
  • Replace existing windows and doors with double or triple glazing.
  • Improve your walls by installing cavity, internal or external wall insulation.
  • Improve your floors by installing insulation in the floor, or between flooring joists.
  • Improve your roof with loft or roof insulation

 

Design that delivers

When planning a retrofit, it's essential to choose a standard as a starting point and create a model to help you understand the building's energy performance and identify areas for improvement.

Retrofitting is often more challenging than building a new home, as it requires careful consideration of several factors and potential consequences. Sourcing a skilled design and construction team is crucial for ensuring a successful retrofit.

 

Setting the bar

It’s important to be aware of PAS 2035, a set of guidelines from the British Standards Institute (BSI), which provides a blueprint for effective retrofitting. While this is not mandatory for privately funded projects (it’s a requirement for government-funded work), it’s worth checking out to understand how to retrofit to a good standard.

It’s possible to retrofit a building without adhering to a specific standard, but doing so can lead to various problems such as underperformance, overheating, or air quality issues. 

 

Getting in the professionals

While it's possible to retrofit a building without specialist designers, it's highly recommended to work with professionals who have experience in this field. Look for designers who are knowledgeable about retrofitting standards and can provide expert guidance.

 

 

Money talks

You may be worried about funding a retrofit project, but help is out there.

Retrofit The Nation is an initiative that aims to make homes as energy efficient as possible by providing free heating upgrades and insulation solutions through Government Eco funding schemes. To apply for a grant, you must complete a short form provided by Retrofit the Nation and they will use that information to recommend the schemes and grants you are eligible for.

You may not be aware but your contractors can apply for 0% VAT tax break on energy saving materials and heating improvements (England, Scotland, and Wales). This makes it more affordable to implement measures like insulation, draught-proofing, and renewable energy sources.

 

Find out more about retrofitting and Saint-Gobain’s solutions