James Gibbs’ wonderful baroque composition of St Mary le Strand terminates a vista flanked by William Chambers’ majestic entrance wing of Somerset House, with its triumphal arch entrance to the courtyard. Built decades apart, their designs were not co-ordinated and Chambers deliberately did not align his façade with Gibbs’ axis. But it is this accidental quality, determined in part by the geology of the Thames bank and the presence of the river itself, and how it has been occupied over time, that gives it an architectural charge.

Recently this space, once a traffic artery, has been declared car-free, allowing pedestrians to enjoy it and giving it the air of a major public plaza at the centre of a notional campus. King’s College is adjacent, the LSE no more than a stone’s throw away, New York University will have a presence nearby and for the last 20 years or so, Chambers’ triumphal arch has housed the entrance to the Courtauld Institute and Gallery, one of the world’s leading centres for art historical teaching, research and conservation.

Founded by the textile tycoon Samuel Courtauld in the 1930s as rather more than just a gallery to house his magnificent collection of largely impressionist and post-impressionist work, it has had several homes, distinguished staff and students (including the notorious Anthony Blunt and, as director Mark Hallett boasts, the current heads of the National Galleries in London and Washington and the British Museum, as well as numerous other distinguished institutions). It now wants to expand the scope of its activities, taking advantage of the links the emerging campus suggests. So it is developing courses with King’s, a range of new MAs in curating, and with the LSE, art and business which might in future spawn another in art and politics.

All of this points towards major architectural interventions. To this end, double Stirling Prize-winners Witherford Watson Mann, who have been associated with the Courtauld for over a decade, have been appointed to develop a masterplan for the diverse estate, with conservations specialists Purcell and Lawson Ward, who are developing a reputation for specialist art-related spaces, such as the National Gallery’s new education centre. It is a daunting challenge. Chambers designed Somerset House on the Thameside site of the palace of the Seymour family (one of whom, Jane, became Henry VIII’s third wife and mother of his only surviving legitimate son) for nine separate institutions, each of which wanted its own identity and independence. Before he could begin to address that task he had to cope with the sloping riverbank site, which he shrewdly and farsightedly resolved by excavating it all to the level of the river, and then building upwards from that datum. He allowed for a generous lightwell to bring light into what are in effect basement levels, some of which house the Courtauld’s library. The distinguished architect and academic David Dunster used to assert that Chambers was the ‘first British architect to think in section’ which, with the proviso of Robert Smithson’s magnificent staircase at Hardwick Hall, is probably true. Chambers’ sectional parti at Somerset House supports it. This feature of the site is certainly better handled than what Robert Adam (Chambers’ great contemporary and rival) managed, slightly further west on the Strand at the Adelphi. There, the vaults, bravely refurbished by the Royal Society of Arts, are truly troglodytical. WWM’s proposals capitalize on Chamber’s sectional abilities, placing the workstations against the windows and keeping the book stacks away from daylight.

Section through the block on the Strand, looking north. Note the tripartite entrance arch in the centre with galleries above, the library vaults below, and the variety of teaching spaces on numerous levels, all to be connected into a coherent whole.

But the scope of the scheme extends beyond Somerset House, into a group of run-down, terraced Georgian houses between it and the unforgiving concrete composition of King’s College, and at least conceptually to other neighbouring institutions. The goal is to expand space for an increase from 700 to 800 students but to offer better accommodation and amenities, as well as upgrading the libraries and number of workplaces. It also has public access to its galleries, with more than 400,000 visitors last year, who also need facilities. As Stephen Witherford wryly notes, there are over 100 level changes across the estate, hardly ideal for accessibility, let alone smooth operations and the easy exchange of ideas on which academic institutions depend.

The grandeur of Chambers’ spaces certainly helps, but WWM have a deft touch when intervening in historic fabric to make it work better for contemporary needs. That is a great asset here, where there is a variety of architectural quality, character and condition of fabric. The cross-section indicates the variety and disposition of spaces the masterplan envisages.

It won’t come cheap: the institute originated with an act of philanthropy, and the donors to the ongoing project are a roll-call of new and old names in art philanthropy, Blavatnik, Clore/Duffield, Weston, Rausing, Rothschild and Wolfson.

The Courtauld is very aware of the whiff of privilege that has traditionally surrounded art history. Recently it commissioned a survey on the state of art history in schools throughout the UK. This found that there is no provision in the UK outside England, and even there only 80 schools offer it to school leaving (A-level) standard. Sixty-one of these are in the private sector (which educates about 7 per cent of children) leaving only 19 in the non-fee-paying sector. These are heavily weighted to the South-east, and correlate fairly closely with those schools at the top of the results league tables and bag the lions’ share of places at Oxford, Cambridge and other leading universities. Where the subject is offered, however, it is slowly rising in popularity.

This lies behind its intention to expand both the subject and its students, under the slogan of ‘new campus, new thinking, new voices’, which is the motor of the masterplan. The new voices include the sort of young people who historically would not have considered an art history degree, and to this end the institute is working hard to develop links at school level. There will be digital programmes, short courses, family events and exhibitions where people will be able to gaze in awe at great works of art. An A-level in history of art is not a requirement (a typical trio for Courtauld students, Hallett notes, is English, History and Art), but interest in the subject obviously is.

Historically focused on Western art of a particular period, bequests and acquisitions have expanded its collection and it is actively moving into non-Western art – with a commensurate expansion of the staff body too. The intellectual programme behind its increasing range of course reflects this, moving art history away from its origins in ivory-towered connoisseurship to seeing it as an active and integrated part of broader social forces. It is a trend that has been in evidence since the 1960s and to see the Courtauld embracing it is welcome and refreshing. And as an institute that combines teaching, conservation and curating it is well placed to take it to new levels.

The entrance will be in the row of houses between Somerset House (right) and King’s College (left). Image: Secchi Smith

It promises not just to animate a magnificent piece of urban fabric, but also to add depth to our understanding of culture and society, as well as what has historically been termed ‘art’. The Courtauld benefited from, and contributed to, the slow evolution of connoisseurship into philanthropy, and academic respectability. The next phase could be much more significant, as academic respectability evolves, in part though the Courtauld’s initiative, into a widespread engagement with, and understanding and enjoyment of, art across society.