Architects Simon Fraser and John Moakes of FBM Architects and AT Awards judges Nana Biamah-Ofosu, Simon Allford, Hanif Kara, Peter Bishop and David Partridge discuss the key drivers behind the retrofit of Brighton University’s Cockcroft Building and the challenges involved in bringing ‘soft brutalist’ buildings in line with current expectations around environmental performance and user comfort. Â Photographer Timothy Soar captures the project as it is today.
The refurbishment of the 15,000-square-metre modernist Cockcroft Building at the University of Brighton is one of the largest retrofits of an occupied academic facility in the UK.
The prefabricated concrete structure is supported by the external frame, which allowed the design team to replace a dark, central circulation space with a south-facing solar corridor. This frees up floorplate for agile social and formal learning workspaces.
All 986 of the original steel-framed Crittall windows have been replaced with thermally-broken aluminium frames with solar control and low-e glazing, radically improving the thermal properties of the building envelope. Internal insulation has been fitted to the external walls to reduce thermal bridging. The newly exposed structure is employed as a heat store, radiating cooler night-time air in the summer and warmer temperatures in the winter.
A pre-retrofit EPC rating of F has been replaced by a post-retrofit rating of EPC B. Energy use has reduced by 57 per cent and annual fuel bills have dropped from £124k to £42k through a comprehensive fabric upgrade, full replacement of services with low-energy, low-consumption fittings, and the large-scale installation of renewables though solar and ground sources.
Originally completed in 1963, the Cockcroft Building exemplifies the ‘soft Brutalism’ of contemporary projects such as Eero Saarinen’s American Embassy and Basil Spence’s science buildings for the University of Exeter.
Simon Fraser, architect Completed in 1963, the original building was designed by the local authority for Brighton Polytechnic. It was contemporary with Eero Saarinen’s American Embassy and similar in design to many buildings by Basil Spence, including Exeter University. The approach is functional rationalism expressing the activities in the building – the upper eight floors are different from the lower floors; there are two interlocking courtyards on the ground floor, and two cores expressed at the back. The style is what you might call soft brutalism. The structural design gives a wide span column-free space providing flexible future-proofed space.
Nana Biamah-Ofosu This an example of a building that has stood the test of time because the team entrusted with its care valued the existing fabric, understood its complexities, capacities and opportunities. It demonstrates how we can retrofit and work with our existing 1960s built heritage without the need for demolition.
External over-cladding was not viable due to then highly articulated nature of the facade. The thermal properties of the building were radically improved by replacing all 986 of the original steel-framed Crittal windows with thermally-broken aluminium windows with low-e glazing to the north and solar control to the south.
John Moakes, architect We quickly realised there were substantial envelope and internal problems common to buildings from this era: There was poor thermal performance, which led to very high energy usage. There was overheating and glare on the large south elevation. There was poor space planning and accessibility. The services were shot and needed complete replacement. This all added up to a very poor environment for teaching and research. There was a dreadful spine corridor running down the middle of the building. It was intimidating, very poor for wayfinding, and inefficient in terms of space usage. The rooms either side of the corridor were grossly oversized for the functions they contained.
Simon Fraser One of the innovations was to introduce a solar corridor on the teaching floors, protecting the large column-free inner spaces from overheating and glare, and creating a bright circulation space with views out.
John Moakes For the office floors, the brief was for multiple cellular offices, which unfortunately didn’t work with the solar corridor. So we retained the central circulation but widened it to include lots of meeting spaces – private, public, formal, informal – so it ceases to be just circulation and becomes a destination in itself.
Where the central corridor has been retained, it has been widened to include formal and informal meeting spaces making it a destination as well as a circulation route.Â
Peter Bishop If we are serious about sustainability then we have here some really encouraging lessons – lessons that suggest that architects can resolve the performance of very sensitive listed buildings without damaging the appearance, and that the new and the old can be juxtaposed, and in so doing enrich the historical narrative of the building. A 1960s structure has been stripped back and redesigned to provide efficient contemporary new teaching and research space. The result is both a beautifully restored building and a lesson that we can adapt and reuse building fabric and retain the embodied carbon within it.
David Partridge It is wonderful to see that the beautiful original structure can be so expressively revealed and enhanced.
John Moakes By omitting ceilings and floor finishes we saved 244 tonnes of C02. All the floor plates that abut the external façade form tremendous thermal bridges. So we’ve actually wrapped the floor slab at every level in insulation both above and below for the first metre back from the façade. This doesn’t eliminate the thermal bridge entirely but it does hugely reduce it.
On the teaching floors the central spine corridor has been replaced with a solar corridor protecting the inner spaces from overheating and glare.
Simon Allford The Cockcroft Building is a very clever reinvention of a rather good looking and well considered post-war education facility – but one that also was fraught with many challenges. What the architects have been done is an exemplar of reinvention; all very much in vogue today. The project, however, is distinguished because it was in fact done a few years back when the vogue was just emerging and most educational projects were designed as much as a shiny image for the front cover of a university applicants brochure as they were for student inhabitation. Cockcroft, a reinvention of a brave new invention, has proven to be ahead of its time and to have survived the test of time.
John Moakes We installed an aquifer thermal energy storage system which delivers 100 per cent of the cooling load of the building and 92 per cent of the heating load. This is a ground source heat pump but with two 90-metre deep bore holes wells, one designated hot, one designated cold. In the summer excess heat is removed from the building and deposited in the hot well with cold water drawn from the cold well to help cool the building. In the winter the cycle is reversed.
Hanif Kara In the foggy world of ‘adaptive reuse’ this project presents a very simple yet well executed exemplar which offers hope for many building in the UK and Western Europe.
John Moakes We put in high-performance glazing, we applied anti-carbonation paint to the external concrete to increase the life-expectancy of the structure, and we cleaned and repaired the brick spandrel panels. On a sunny day it looks like a Mediterranean hotel. Who wouldn’t want to study there?
The decision to omit ceilings and floor finishes saved 244 tonnes of C02.
Project presentation
View Simon Fraser and John Moakes from FBM Architects give a presentation on the Cockcroft Building below
Additional Images
