Detailed 3D modelling, more than 15,000 drawings and carefully planned offsite fabrication have seen specialist envelope contractor Prater play a key role in the completion of the new £172m Ysbyty Ystrad Fawr (Caerphilly Local General Hospital).
The project was managed under the ‘Designed for Life’ procurement framework, a Welsh Assembly Government initiative aimed at speeding up hospital building programmes by encouraging greater collaboration between major project partners.
Replacing the 85 year old Caerphilly Miners’ Hospital, Ystrad Mynach Hospital and a number of smaller community hospitals in the area, the 269-bed facility is the first 100% single en-suite room hospital in Wales. As well as improving patient dignity and efficiency, this also minimises the risk of hospital acquired infections. Facilities on-site include a 24-hour local emergency centre and integrated mental health unit.
Designed by Nightingale Architects for Gwent Healthcare NHS Trust, Caerphilly Hospital is the largest project in a public sector investment programme aimed at transforming the principality’s healthcare estate.
Under the procurement framework agreement, main contractor BAM Construction was responsible for establishing a supply chain that would be involved in the project from an early stage, and Prater was appointed to design the building envelope.
‘’The shape and external complexity of the envelope made it a particularly critical part of the construction process,’’ explains BAM Construction project manager Andrew Cavil.
The hospital, a four-storey, 30,000m2 building designed in a distinctive zig-zag shape, has been built on reclaimed brownfield land next to the River Rhymney. While the existing flood bund has been upgraded, the building has also been designed with car parking beneath the building and facilities starting on the upper ground level. This also enables maximum use of natural light for inpatient accommodation, a central requirement in the design of a building in which every room has a window.
“The narrow plan design means the ratio of envelope to floor area is much higher than with wide plan designs,” continues Andrew Cavil. “Our timescales meant that we needed a solution that used materials other than traditional brickwork. We needed an envelope that was quick to erect and economically viable, one that would make the building weather-tight as quickly as possible and enable other work to continue.”
The complex geometry of the building required Prater to undertake 3D modelling and produce as many as 15,000 drawings. In all, 11,000m2 Micro-Rib Architectural Wall Panels in Silver Metallic and Obsidian from Kingspan Insulated Panels provided the high performing, fast track construction the project demanded. The wall panels were fabricated off site, delivered as needed and bolted to the concrete frame building. The panels offer highly efficient thermal performance with low air leakage of 5m3/hr/m2 or better and reliable insulation continuity, as well as assured fire performance, delivering two essential aspects of hospital design.
The full building envelope package included Kingframe architectural façade system, lightweight Metsec walls, Kingspan architectural wall panels, Natura rainscreen board system, Permatec hot melt structural waterproofing and Kalzip standing seam roof system.
"The overall value of the building envelope was just under £10m,” explained Andrew Cavil. “On a project of this magnitude, we needed a partner with a track record of being able to handle projects of this size. Prater’s experience and ability to assist with developing the design proposals were important factors in our decision to appoint them.”
