Since September 2023, the College has restricted access to various areas within the College due to the presence of Reinforced Autoclaved Aerated Concrete (RAAC) in the College’s roof structures, principally the original Arne Jacobsen site. This included the Kitchen, Dining Hall, JCR, SCR, Administration Block, Wolfson Library, the Bernard Sunley Building and the top floor of the Accommodation Blocks Staircases 1 to 16.
St Catherine’s College is pleased to announce that the Planning and Listed Building Consent Application to address the use of RAAC in several of its Grade I listed buildings was approved by the Oxford City Council. In October 2024, the College signed a construction contract with Beard to begin the remediation works and these works began early in 2025.
Please find further details below about the ongoing project.
A message from the Master about RAAC
In the late 1950s when the architect Arne Jacobson was designing maximum elegance and simplicity into the modern cathedral-like structures that would become St Catz, he was keen to use a newly developed concrete mix, invented in Sweden, offering the perfect structural, aesthetic and economically viable solution.
RAAC – Reinforced Autoclaved Aerated Concrete – is a lightweight material, cheaper and easier to mould than traditional concrete due to the use of aluminium powder and calcium hydroxide, which create air pockets during the manufacturing process. But sadly, the very things that make it light and versatile – the holes – also make it highly susceptible to damage from moisture which can corrode the reinforcing steel and weaken the structure. Which no-one, including Jacobsen, knew at the time.
Plenty of architects of new schools, hospitals, and public buildings took advantage of this lightweight but strong material. But by 1995 definitive reports of cracking began to emerge and when, in 2018 the roof of a primary school collapsed – thankfully without injuries – it became clear that doing nothing was not an option. So although the College buildings had been regularly monitored and maintained since their construction and there had been no failures of the RAAC panels, we engaged independent consultants to undertake appropriate risk assessments. And inevitably and suddenly, St Catz had to announce a complete closure of most of its most important buildings: the library, lecture hall, common rooms and all the staff offices.
Work started on Phase 1 early in 2025 on the single-storey Junior Common Room, Senior Common Room, Administration Office Block and the Kitchen.
Phase 2, works on the Student Accommodation rooms and Wolfson Library, will follow at a date not yet set and also as funding permits.
It is currently expected that the first areas, including the JCR, will hopefully be ready for use by the end of 2025. The Hall and the Bernard Sunley Building are currently expected to be ready in the first few months of 2026.
So, as you can imagine, this has involved massive upheaval. And if you are familiar with the site as Jacobsen designed and built it, frankly, it’s heartbreaking. But there is no way round it. And it must be said the creativity, patience, flexibility and sheer hard work needed and freely given by all College academic and support staff, and students alike is genuinely moving.
We’re all looking forward to the day when our cherished college is back – restored, whole and beautiful.
— July 2025
What solution has been proposed?
The Planning and Listed Building Consent Application, which was developed after an extensive pre-application process with Oxford City Council, Historic England, Twentieth Century Society and the Historic Parks and Gardens Trust, proposes the replacement of the affected roof structures to ensure the longevity of the College site by mitigating harm and preserving its iconic Jacobsen design.
The remediation plan begins with the Kitchen, JCR, SCR, Dining Hall, followed by the Bernard Sunley Building and Library, all forming the initial phase of the project, with works scheduled to commence in August. A second phase will commence later to address remediation of the Accommodation blocks, to Listed Building Consent and planning permission.
To read the specifics of the proposals, please see the Design and Access Statement and Heritage Statement.
The notices of grant of listed building consent can be viewed here:
The original applications are available to read on the Oxford City Council planning portal:
What is the timeline for proposed works?
St Catherine’s College is very pleased to announce that it has signed a construction contract to replace roof structures comprising “Reinforced Autoclaved Aerated Concrete” (RAAC) in the grade 1 listed Arne Jacobsen buildings. The College was pleased to receive planning permission from the Oxford City Council on 30 July 2024 and have since been collaborating with Beard Construction to execute the work, to bring the buildings back into operational use.
The initial work, completed by Beard, involved erecting scaffolding to provide temporary roofing structures, and to provide internal protection to the historic fabric that the structures comprise. The first building to be remediated includes the single-storey Junior Common Room, Senior Common Room, Administration Offices and the Kitchen. The removal of RAAC commenced early in 2025, with the roof replacement beginning shortly after. It is currently expected that these areas will be ready for use by the end of 2025. Work on the College’s Dining Hall has begun, with expectation that it will be available along with the Bernard Sunley Building in the first few months of 2026. The College continues to explore the feasibility of re-roofing the Wolfson Library, with the Student Accommodation rooms to follow in due course, as funding permits.
Who is involved?
The project has gone through a robust planning process involving many partners. These include:
Project Manager and Cost Consultant: AtkinsRéalis
Architect: Oxford Architects
Consultant Architect to the College: Pendery Architecture & Heritage
Planning and Heritage Consultant: Edgars
Landscape Architect: Colvin & Mogridge
Services Engineer: Ingleton Wood
Structural Engineer: AKS Ward
Kitchen Designer: Bentley Consulting
Ecology Consultant: MKA Ecology
Aboricultural Consultant: Tree Frontiers
Building Contractors: Beard Construction
Oxford City Council
Historic England
Twentieth Century Society
The Historic Parks and Gardens Trust
St Catherine’s College Governing Body
Is College still open?
Yes, St Catherine’s College is still open as a functioning, lively college thanks to the hard work of our on-site teams. We have installed a number of temporary structures, including a Dining Hall, Lecture Theatre and Seminar Suites and JCR, alongside conducting extensive remedial work to keep our iconic staircases open.
What can I do to help?
We welcome gifts of all sizes to support the refurbishment and re-opening of our communal buildings, in particular, the Wolfson Library, and are grateful to the hundreds of alumni and friends who have already pledged their support. To learn more about how to make a gift, click here.
last updated 1 July, 2025