Why We Should Air Pressure Test Existing Dwellings
Optional – But Impactful for EPC Ratings
With the rollout of RDSAP 10 from June 2025 in Northern Ireland, airtightness testing is no longer just for new builds. For the first time, measured air pressure test results can be used to improve the EPC rating of existing dwellings. For many properties sitting just below a target EPC band, this change creates a valuable opportunity: a low-cost, non-invasive way to gain crucial SAP points — without committing to major retrofit works.
The Problem with Default Assumptions
Under previous RDSAP versions, airtightness was assumed based on the property’s age and construction type — often overestimating air leakage and penalising homes that were well-sealed or had been maintained to a high standard. For older properties in particular, these default assumptions could unfairly reduce the EPC score.
The RDSAP 10 Opportunity
Now, if an air pressure test is carried out by a qualified professional, the measured air permeability value can be entered directly into the EPC calculation. This offers a more accurate and often more favourable assessment of a dwelling’s energy performance.
Who Benefits Most?
- Landlords needing to meet minimum EPC thresholds (e.g. E to D or D to C)
- Vendors aiming to position their property more attractively on the market
- Owners of solid-wall or historic homes that cannot easily be insulated
- Portfolio managers trying to optimise compliance without major capex
Why Air Testing Makes Sense
✅ Cost-Effective
An air test typically costs less than common retrofit measures — and can deliver an equivalent or better EPC uplift.
✅ Non-Disruptive
No building work, no tenant disturbance. The test takes just a few hours and leaves no trace.
✅ Quantifiable EPC Gain
On borderline cases, air testing can shift a property up by a full rating band (e.g. from D to C) — with measurable, reportable results.
✅ Strategic Retrofit Planning
For those considering phased upgrades, the test provides a reliable baseline to guide insulation, ventilation, and heating improvements.
It’s Optional — But Strategic
Airtightness testing is not mandatory under RDSAP 10. But where properties are close to compliance thresholds, it can offer a decisive advantage. Rather than guessing or over-investing, test, verify, and improve intelligently.
Interested in Boosting Your EPC Rating?
We offer airtightness testing across Northern Ireland, carried out by qualified professionals using calibrated equipment. If your property is within range of a higher EPC band, an air pressure test might be the simplest and smartest move you can make.
Contact us today to book a test or discuss your project.
