Kingspan Tek® makes barn enerphit for purpose

Sjölander da Cruz Architects have used the Kingspan Unidek Aero® Roofing System and Kingspan TEK® Cladding Panel to help breathe new life into a run-down, asbestos clad barn, creating a stunning architectural studio which meets the exacting requirements of the Passivhaus EnerPHit standard.

The repurposed barn, dubbed ‘The River Studio’ after the River Avon which borders the site, is now almost unrecognisable from its former use as an engineering workshop. The original asbestos cladding was stripped back and Kingspan TEK® Delivery Partners, Lowfield Timber Frames, designed and installed the Kingspan Unidek Aero® Roofing System and Kingspan TEK® Cladding Panel externally on to the existing steel frame.

With a specific energy demand of just 18 kWh/m²yr, the completed studio far surpasses the level of performance required by the EnerPHit standard (25 kWh/m²yr).

Marco da Cruz, Director from Sjölander da Cruz discussed the project:

“We have pushed energy efficiency in all our previous work and The River Studio offered us a unique opportunity to design and monitor an EnerPHit building. Constructing around the existing frame presented us with several design challenges and we needed a building envelope solution which would allow us to preserve internal space whilst also meeting the EnerPHit performance requirements. Having worked extensively with structural insulated panels (SIPs) in the past, the Kingspan Unidek Aero® Roofing System and Kingspan TEK® Cladding Panel were the natural choice.”

“Headroom inside the barn was restricted and this meant we had to limit the thickness of the floor build-up. The Kingspan TEK® Cladding Panel and Unidek Aero System allowed us to compensate for this with enhanced wall and roof U-values from a minimal overall construction depth. The panels contributed to the continuous airtight layer and spanned between the existing structure, reducing the need for a costly secondary frame.”

The Kingspan TEK® Cladding Panel and Unidek Aero® System, comprising high performance structural insulated panel’s (SIPs), were factory pre-cut to the project’s requirements by Lowfield Timber Frames. This offsite approach minimised site waste and allowed the erection to be completed in less than 2 weeks.

In order to meet the target roof U-value of 0.12 W/m².K Sjölander da Cruz Architects specified the roofing panels in a 254mm thickness. The panels are able to span lengths of over 7 metres and feature a unique timber rib construction which eliminates repeated thermal bridging.

To complete the wall build-up 100 mm thick Kingspan Thermawall TW55 was fitted on the outer face of the Kingspan TEK® Cladding Panels, achieving a final wall U-value of just 0.10 W/m².k and Kingspan’s premium performance Kooltherm K3 Floorboard was also installed beneath the barn’s screed floor.

The Kingspan Systems can also help achieve very low air leakage rates and to further enhance this airtight tape was applied to all panel junctions inside the studio, combined with a membrane beneath the roof and floor delivering a final air leakage rate of 0.40 air changes at 50 Pa. A mechanical ventilation heat recovery (MVHR) unit was installed to provide a constant flow of fresh air throughout the building. The unit uses stale exhaust to heat incoming air, further reducing energy bills and Sjölander da Cruz Architects turned the steel ductwork into a feature within the Studio.

Triple-glazed windows were also installed on the studio in the pre-cut openings and a western red timber façade was fitted externally, allowing the studio to subtly blend in with its green belt surroundings.