Brutalism remains the most controversial architectural style of the 20th century with the British public. Perhaps no architect brought more attention to it than Denys Lasdun, whose National Theatre masterpiece was famously compared by Prince Charles to a nuclear reactor when it sneaked into the heart of London.When it comes to working with historic buildings, no UK practice has recently attracted more attention than John McAslan + Partners (JMP), with its restoration of the iconic Iron Market in earthquake-shattered Port-au-Prince, Haiti, and its large, lyrical new entrance at King’s Cross station. Lasdun and McAslan’s works come together at the School of Oriental and African Studies, aka SOAS, whose Grade 2* listed library was designed by Lasdun. JMP has made transformative interventions, and has plans for more. But things began less than auspiciously when John McAslan and Lasdun first met. McAslan invited Lasdun to give a lecture in Edinburgh in the Seventies, and hosted a dinner in his honour. Afterwards, he offered to drive Lasdun back to his hotel. McAslan recalls that ‘by this time it was well past midnight and pouring with rain, Lasdun had an early train to catch the following morning back to London and was clearly tired. We piled into my antiquated Ford Anglia – which promptly refused to start. So Lasdun got out, getting soaked in the process, and gamely offered to push the reluctant car. He gave an almighty shove, I slammed the car into gear – and the gear-stick came away in my hand.’ The men then squeezed into a phone booth, summoned a taxi, and as Lasdun was dropped off, he made McAslan promise to pick him up at 7am. ‘And of course, I over-slept the following morning.’

Luckily, Lasdun made it unaided to London, in time for an interview about the European Investment Bank in Luxembourg, which is now a highlight of his legacy. Their next encounter was shortly before Lasdun died in 2001, at Lasdun’s offices in Millbank. He claimed not to remember the Edinburgh incident at all. McAslan was accompanied by SOAS’s head of estates and ex-RIBA president Bryan Jefferson, and the agenda was the SOAS library, officially called the Philips Building. Completed in 1973 and sitting behind the older SOAS building by Charles Holden, it is an exercise in Lasdun’s beloved concrete – a rectangular block of six levels (or ‘strata’ as he may have said) emphasising the horizontal externally, and centred internally on a spectacular terraced atrium beneath a coffered ceiling, formed by a grid of square skylights set diagonally to the building, like a vast, almost metabolist lid rolled across it. Lasdun designed exterior terraces on its east and north sides. SOAS is part of the long march of University of London buildings that had been eating up swathes of Bloomsbury since the Twenties, and is adjacent to Lasdun’s far more aggressive and monumental Institute of Education stretched along Bedford Way. Even Senate House, Charles Holden’s heavy 1932 art deco university skyscraper, clashes less with the surrounding Georgian terraces than that, but the SOAS library is comparatively discreet, with more modest concrete plant structures on its skyline than the massive, repeated sculptural statements of the IoE.

In the intervening years, operational problems with Lasdun’s designs grew – poor air circulation, cramped reader space and, not least, a massive increase in the volume of books (which now number perhaps 1.5 million). Furthermore, his external terraces were not being used. McAslan was commissioned to prepare a campus masterplan for SOAS, from which the plan emerged to extend the library across the east and north terraces in double-height steel frames, curtain walled with double glazing. These extensions, completed in 2006, created 170 new reader spaces and effectively turned the building experience inside out. Readers now face out to light and trees on the old terraces’ level and the floor above extends over it within the new structure, while the books are on floors that seamlessly reach to the four-level-high atrium, with its central Reading Room still at its base. Intakes in the curtain wall introduce air, which convects to roof lights, so the library is now naturally ventilated. Glass coating and sensor-activated blinds that roll down full length combat solar gain and glare. This is a crucial element of JMP’s ongoing aim to achieve a BREEAM Excellent rating, which continues with a campus-wide energy strategy.

JMP also designed the Research Block, a thoroughly contemporary-looking structure completed in 2003 and almost hidden away between Lasdun’s library and the Holden school block. The latest phase was the library transformation project, which refurbished the ground floor of the library. It introduced new study rooms on the east side, a wide reception area and a small exhibition space, the Wolfson Gallery. The recently completed £4m works started in 2010. The library now has two-fifths more seating for readers, and 11 per cent more space overall. Concrete characterises brutalism – the very term comes from Le Corbusier’s expression ‘béton brut’ for raw concrete, rather than any brutish allusions – and Lasdun revelled in it. In a 1976 TV interview with Peter Hall about the just-completed National Theatre, he commented that, ‘it's a very intractable material, but it can be a very beautiful material if it is used the way that its own nature intends it to be used.’ Lasdun brought variety to SOAS’s concrete – smooth-surfaced with the wood patterning from the shuttering effect in the cores, clean-surfaced in internal concrete columns, and throughout, the rough concrete with aggregates of the sort that, for example, Chamberlain, Powell and Bon used at the Barbican.

JMP found his concrete in poor repair. James Dixon, JMP’s associate director in charge of the transformation project, says that ‘all the cores were covered in pock marks, wall sockets and marks. We cleaned all of these up’. Dixon says that they exposed yet more concrete in the ceiling, to increase ceiling height and use its thermal mass to energy-saving advantage. He describes this aspect of the work further – removing ‘grotty and broken tiles that were part of the original. We used a lime wash that brings out the concrete without exposing its ragged construction…’ JMP’s Phase 2 of works has been drawn up, but awaits funding. It entails addressing the still-hindered wheelchair access between book shelving; cladding the main atrium in timber and reducing the concrete at balcony edges ‘to bring some warmth into the space,’ Dixon comments. The Reading Room is to be enclosed in glass and the great skylight grid refurbished, set with clear glass to be used, he adds, ‘as a great stack to help drive the vent systems’. Lasdun had a reputation of vigorous opposition to interventions in his designs, but at the end of his life he seemed to become more open to them. In 1999, the same period he was consulting on SOAS, he also worked with Munkenbeck & Marshall on its regeneration of his idealistic 1957 Keeling House ‘street in the sky’ council tower in Bethnal Green. While he had reservations about its conversion to trendy private residences, he helped push through approval for a new lobby and penthouses, and even hung out with contractors, discussing work over tea. With SOAS, where Lasdun had earlier not got on with the librarian and disliked his partitioning and layouts, McAslan recalls that, in consultation, he was ‘largely unruffled at the thought of the proposed adaptation of the library building’. McAslan also consulted with the Twentieth Century Society, which he was critical of at the time, and English Heritage.

John McAslan recalls Lasdun as ‘tough, occasionally cantankerous, committed and, above all, honourable’. JMP has been responsive to, rather than tough on the library’s modern needs, and calm rather than cantankerous with the major interventions. But the second part of the description certainly applies to JMP’s  SOAS work – its commitment now is into its second decade, and it has never failed to treat Lasdun’s unique structure, spatiality and surfaces with anything other than respect.