Schwarzman Centre achieves Passivhaus standards

The University of Oxford’s Stephen A. Schwarzman Centre for the Humanities has been confirmed as the largest Passivhaus certified university building in Europe and the world’s first Passivhaus concert hall.

Laing O’Rourke successfully handed over the Centre in September, making it the 12th project delivered to the University of Oxford in the past 25 years.

Receiving this globally recognised certification requires exceptional levels of performance across multiple criteria, including insulation, airtightness, manufacture, heating and cooling, energy, glazing, ventilation, and more, helping to create a more sustainable building.

Professor William Whyte, Senior Responsible Owner for the project said: “This is a stunning achievement by the designers and builders of the Schwarzman Centre. For a project of this scale and complexity to be awarded Passivhaus certification is also a testament to the commitment of the university to reach its bold environmental sustainability targets. It has been a privilege to work with a team of such remarkable professionals."

Laing O’Rourke’s Project Director, Steve Holland, added: “Delivering one of the world’s most complex Passivhaus buildings demonstrates the strength of our people, fully utilising our approach of digital engineering, manufacturing excellence and direct employment to ensure certainty in project delivery.

“To build The Stephen A Schwarzman Centre for the Humanities, high-architecture with world-class acoustics, in a tight footprint in Oxford was a challenge in itself, but to do it to Passivhaus standards was only possible thanks to our modern methods of construction. We were able to manufacture products offsite, improving the quality, and improve the lives of our people by simplifying delivery on site.”

To accomplish the projects' insulation, airtightness and programme goals the external envelope is fully panelised and prefabricated. This was realised using a digital build strategy to technically verify and resolve all interface details. Modern Methods of Construction were used to manufacture and assemble the façade, off-site to exacting quality and performance standards. This process was made simpler thanks to Laing O’Rourke’s integrated supply chain and its Centre of Excellence for Modern Construction facility in Worksop.

To achieve Passivhaus certification at this scale, a custom quality management process was developed, using in-house Laing O'Rourke quality assurance procedures, to verify and record construction integrity at every stage of installation. This helped the team maintain certainty of information and responsibilities on site, across multiple parties, while maintaining the pace of construction.

The project achieved a final building airtightness test of 0.66 m3/m2/h @50Pa (0.16ach), with an external envelope average weighted U-value of 0.30 W/(m²K) comprising, 'solid' wall elements of 0.16 W/(m²K) and a roof of 0.12 W/(m²K).

A bespoke assessment criteria for Primary Energy was used by the Passivhaus Institute to certify the building. On commissioning, the systems performed better than expected and, coupled with very high performing glazing systems, brought the space heating demand to less than 8kWh/m2/y. The small amount of heating and cooling still required by the building is provided by separate roof mounted air source heat pumps and chillers.

The citation from Passivhaus Certifier Lazlo Lepp of the Passivhaus Institute said: “The design, construction and commissioning of such a large building with complex usage requires an extraordinary team effort. This team spirit and high level of motivation of all those involved was clearly noticeable from the beginning to the end and was an essential part of the quality achieved. I am delighted to confirm that the high-quality standards required for Passivhaus certification have been met in this project."

Early performance monitoring over this winter has already demonstrated that the centre’s heating system requires approximately half the energy of similar non-Passivhaus buildings on a pro rata basis.

The facility which brings together seven of Oxford’s internationally recognised Humanities faculties, as well as two research institutes, a new library, performance spaces welcomed students in September.

Photo credit in header image: Hufton+Crow Photography.