Are you looking for ways to make your home warmer, greener and cheaper to run? Understanding the retrofit process is the first step towards improving energy efficiency and reducing costs, whether you’re a homeowner, tenant or landlord.
This on-demand webinar, delivered by Building Energy Experts as part of Retrofit Action Week South West, walks through what retrofit is, how a professional retrofit assessment works and how different testing methods help identify the changes worth making to a home.
In this webinar you’ll learn:
- What retrofit is and why it matters for energy efficiency
- How professional retrofit assessments work and what they involve
- The stages of the retrofit assessment process
- How air tightness testing, thermographic surveys and borescope cavity wall inspections each help identify inefficiencies
- What types of retrofit measures are available
📺 Watch the webinar:
What is Retrofit and How is it Defined?
At its simplest, retrofit means improvement work on an existing building to improve its energy efficiency – whether that building is 100 years old or 10. It’s become something of a buzzword, but the definition itself is straightforward: any upgrade to an existing home that makes it more energy efficient.
Why Retrofit? The Key Benefits
The most commonly discussed reason to retrofit is energy efficiency: the process highlights inefficient areas of a home – poor insulation, an outdated heating system – and how to fix them, lowering the energy needed to keep the house warm and comfortable. That reduces both bills and carbon footprint.
Just as important, though less discussed, are the wellbeing impacts. A warmer, more comfortable, cheaper-to-heat home reduces financial stress, and retrofit can directly target issues like mould and damp – problems that carry real health risks, particularly for people who are vulnerable, elderly or living with conditions like asthma.
The Stages of the Retrofit Assessment Process
Building Energy Experts handles the first four stages of the retrofit process:
- The brief – understanding what you feel the issues are with your home, whether that’s insulation, doors, windows or something else.
- The assessment – a detailed, comprehensive survey of the home.
- Testing – further diagnostic testing carried out alongside the survey to confirm and quantify the issues found.
- Coordination and design – looking at remedial works that weigh up cost against overall improvement to the home.
What Does a Retrofit Assessment Involve?
A retrofit assessment is a full condition survey of the home, gathering holistic data on its overall state. This typically covers:
- Building fabric – every individual component that makes up the home: doors, windows, walls, heating system, ventilation, insulation and more.
- Overall condition – checking for issues like mould, damp and condensation, which can often be traced back to problems with the building fabric.
- Structural concerns – cracks in walls or ceilings or other damage to the property.
Part F ventilation testing – covering extract fans, trickle vents and fan flow rates – is undertaken in every retrofit assessment as standard.
Retrofit Testing Methods
Alongside the assessment itself, Building Energy Experts typically carries out three further types of testing.
Air Tightess Testing
Air tightness testing measures air permeability – in simple terms, how draughty a property is, and how much warm air is escaping through doors, windows, insulation and other gaps.
Two methods are used: a blower door test, which creates a pressure difference across the whole building and is particularly good for diagnosing and locating exactly where air is escaping (common areas include skirting boards, doors, window, and pipework); and a Pulse test, which uses a pressure shock wave rather than a sustained pressure difference to identify air leakage.
Both produce an air permeability score quantifying how draughty a home is – for diagnostic purposes, a blower door test is generally recommended, since it allows leaks to be physically traced. Pipework and plumbing penetrations are a common, often-overlooked source of leakage alongside the more obvious doors and windows.
Borescope Cavity Wall Inspection
Borescope cavity wall inspection uses a camera attached to a drill, passed through a small hole in the cavity wall, to visualise what’s happening inside. This is particularly useful for checking the continuity of existing insulation — insulation can settle or sink within a cavity over time – and for assessing its general quality and degradation.
Thermographic Surveys
Thermographic surveys use thermal imaging cameras to show where heat is escaping from a property, and to identify thermal bridges: areas with a stark temperature transition, typically caused by gaps in insulation, that lose heat rapidly and are prone to mould, damp and condensation as a result.
How it All Fits Together
Here’s how these pieces typically combine in practice. Say a resident on a retrofit project tells us that their home always feels cold and heat seems to disappear quickly once the heating goes off. Our assessor visits and, during the retrofit assessment, notices condensation and mould around the windows, and walls that feel cold to the touch. Alongside the survey, we carry out a borescope survey and an air tightness test.
The borescope survey shows the insulation has poor continuity – it’s settled within the wall, leaving gaps where heat is escaping (which explains the cold walls). The air tightness test shows significant air leakage around the doors and windows, often down to poorly fitted or ageing seals. Together, this points to a clear diagnosis: a draughty property with high air permeability, compounded by insulation issues – giving a solid basis for deciding which retrofit measures would actually address the root cause.
What Types of Retrofit Measures Are Available?
Retrofit measures generally fall into three categories:
- Fabric measures – changes to the building’s actual construction: insulation, windows, doors and anything else addressing air tightness. These address the root cause of many issues directly.
- Service measures – additions or changes to systems like heating, ventilation, air conditioning and lighting (e.g. switching to LEDs). Air source heat pumps fall into this category.
- Renewable measures – technologies using a renewable source to power or heat the home, such as solar panels or solar water heating.
The right combination depends on your budget, your goals and – critically – what the assessment and testing actually found.
Q&A Highlights
A few points that came up during the live Q&A are worth passing on:
- Cost varies by scope. Pricing depends on which services you need across assessment, testing, coordination and design – get in touch for a quote based on your specific brief.
- Funding is available in the South West. Retrofit West offers subsidised retrofit testing and assessment costs for residents in Bristol, Bath & North East Somerset and South Gloucestershire. Beyond the assessment stage, financing options such as fixed-interest home improvement loans are also available nationwide.
- TrustMark is a good way to find accredited installers for whichever retrofit measure you’re considering – search by measure and location to find accredited businesses near you.
- If you can only afford one test, air tightness testing (alongside Part F ventilation testing) gives the most holistic picture of what’s working in a home and what isn’t.
- Testing before installing measures matters. Without it, there’s a real risk of spending on a measure – solar panels, for example – without addressing the underlying issue actually driving your bills or cold rooms, whether that’s air leakage, poor insulation or something else. Assessment and testing make sure the investment goes where it will actually help.
What’s Next?
We offer a comprehensive range of energy efficiency testing and assessment services to help guide your home retrofit.
If you’d like to talk through what a retrofit assessment would involve for your property, we’re happy to help.
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