Chichester Air Test

We recently supported JR Baker Construction on a striking contemporary new build just outside Chichester. Following our earlier pre-test inspection, we returned to complete the final air permeability (blower-door) test as part of the Part L pre-completion checks. The home’s generous full-height glazing and open, airy layout were complemented by beautifully crafted Iroko timber solar-shading—a smart architectural touch that also helps with summertime comfort.

The dwelling achieved an air permeability of 5.15 m³/(h·m²) @ 50 Pa, comfortably below the project target of 8.0. That means the build met its air-tightness objective and can proceed to handover—great news for both the client and the contractor.

Our approach

1. Pre-test inspection
   On our first visit we carried out a focused inspection to identify potential leakage paths before finishes were complete. We reviewed common risk areas such as service penetrations, window and door interfaces, loft hatches, and junctions at floors/ceilings and provided the site team with practical, buildable sealing recommendations.

2. Final blower-door test
   With the remedial sealing completed, we installed the blower-door in the principal entrance and depressurised the dwelling to 50 Pa. The building responded well, with stable readings and no significant leakage hotspots during diagnostic checks—exactly what you want to see on test day.

Why the result matters

• Compliance & sign-off: The 5.15 score is below the agreed threshold of 8 desiganted by the Design Stage SAP calculation, supporting Part L compliance and allowing the project to move forward to completion and handover.

• Comfort & efficiency: Good airtightness reduces uncontrolled draughts and helps the heating and ventilation strategy perform as designed, important in a home with extensive glazing.

• Future performance: Combined with the Iroko shading, the airtight envelope sets a solid foundation for year-round comfort, lower bills, and reduced carbon.

Architectural highlights we loved

• Iroko timber shading: Elegant vertical fins soften solar gain across the larger glazed elevations while adding texture and warmth to the exterior.

• Expansive glazing: The full-height doors and windows deliver a light-filled, open feel and strong connection to the landscape.

• Quality of detailing: From the flintwork to the joinery, the craftsmanship on site was excellent and reflected in the clean test result.

What we supplied

• Pre-test advice with specific sealing actions

• Final air permeability test

• Digital certificate and results for Building Control/SAP

• Practical feedback for the project record

Final word

This was a pleasure to work on—great team, beautiful design, and a tidy test result. Congratulations to JR Baker Construction and the wider project team on delivering a high-performing contemporary home.

Thinking about your own or next project?

BEAT Solutions support housebuilders, developers and architects with air permeability testing, SAP, SBEM, overheating assessments (TM59 & simplified), u-values & ψ-values, condensation risk analysis, ventilation testing, and more.
If you’d like a smooth path to Part L complianc and fewer surprises on test day please get in touch and we'd be glad to help. Call us on 01489 565920.