What a Home Energy Audit Actually Involves
A home energy audit is a systematic assessment of where your home loses heat and energy, what that costs you, and what the priority improvements are. Done well, it goes significantly beyond an Energy Performance Certificate (EPC). EPCs assess the property against a theoretical benchmark using standardised assumptions; an audit looks at your actual energy consumption, your actual heating pattern, and your actual construction type.
A comprehensive audit typically includes: a visual inspection of the loft, walls, floors, and windows; a review of your energy bills over the past 12 months; thermal imaging (in heating season) to visualise heat loss through the building fabric; an air permeability assessment; and a heating system efficiency review. The output is a prioritised improvement plan with estimated costs, savings, and payback periods for each measure.
What Thermal Imaging Reveals
Thermal imaging cameras detect surface temperature differences across walls, ceilings, and floors. Cold spots indicate heat loss — through gaps in insulation, uninsulated sections, thermal bridges (structural elements that conduct heat), and air infiltration. For East Anglia properties, common findings include: missing or patchy loft insulation, cold spots around window frames and lintels, heat loss through chimney breasts, and air infiltration through external wall voids.
Thermal imaging works best when there is a significant temperature difference between inside and outside — ideally at least 10°C. This means the optimal window for thermal imaging audits in East Anglia is October to March. Images taken in summer when the temperature differential is small are much less informative. If you want a thermal imaging audit, book it in autumn or winter.
Typical Findings for East Anglia Homes
We complete free site surveys across Cambridgeshire, Norfolk, and Suffolk. The most common energy efficiency issues we find are: partially filled or compressed loft insulation (common in properties built 1950-1990 that had insulation added later but which has settled), unfilled cavity walls (many properties built pre-1975 with 75mm cavities that were never filled), gaps around pipework penetrations and consumer units, and poorly sealed loft hatches.
These low-cost improvements deliver rapid payback. Topping up loft insulation to 270mm costs £300-£600 and typically saves £100-£200 per year — payback under 4 years. Cavity wall insulation costs £500-£1,500 for most houses and saves £200-£400 annually — payback 2-5 years. Draught-proofing costs £200-£400 DIY and saves £100-£200 per year.
When to Do the Audit vs When to Just Install
If you are planning a major installation — solar panels, battery storage, or an EV charger — you do not need an audit first. These measures work independently of the building fabric and the survey we do for each installation is sufficient. If you are planning a heat pump, an audit (or at minimum, an MCS-compliant heat loss calculation) is strongly recommended before installation. Fitting a heat pump to a very poorly insulated property without addressing the worst losses first will result in higher running costs than necessary.
The most valuable audit is one done before a whole-house retrofit: when you are planning multiple measures and want to prioritise them by ROI. In this context, an audit saves money by ensuring you invest in the highest-return improvements first, rather than following a generic checklist.
Free Survey vs Paid Audit
Green Hat Renewables offers free site surveys for all our installation services. These are technically-focused surveys to determine whether a property is suitable for the system being proposed, what specification is needed, and what the expected generation or savings will be. They are not comprehensive energy audits.
A full energy audit with thermal imaging is typically priced at £200-£500. Some local authorities and energy charities offer subsidised audits for lower-income households. If you are considering a whole-house retrofit and want to understand your full options before committing to specific measures, a paid audit is money well spent. Contact us to discuss whether a free survey or a paid audit is the right starting point for your property.
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