The back story of John McAslan’s modernism is set in and around Dunoon, Argyll, where he spent much of his boyhood. It was at nearby Holy Loch that he first saw the implacable, superfunctional forms of American nuclear submarines at anchor. And was there something eerily serendipitous in his early education at a boarding school in Clackmannanshire (with a grandly Doric main façade by William Playfair) called Dollar Academy.

His architectural sensibility was certainly pricked by these quasi-American indicators, but they only took detailed shape during America’s bicentenary year of 1976,when he toured the country absorbing great buildings, ranging from Falling Water to the structures of Burnham and Sullivan.

A two-year spell with Cambridge Seven Associates in Massachusetts fused him to American modernist architectural methods, based on multi-skilled studios. And McAslan found an extension of this idea – though under more powerfully singular direction – when he joined Richard Rogers in the Holland Park studio in which he himself eventually set up John McAslan + Partners (JMP) after parting with his original co-partner, Jamie Troughton. Their first commission was the conversion of a 1950s car showroom in Camden Town into the Design House. Other early projects were characterised by sharply clarified details and graphic effects. The practice was commissioned to design Apple's headquarters in Stockley Park, and was the first British architectural firm to complete a building at Canary Wharf.

Today, McAslan is still “trying to break out of the straitjacket of modernism.” His co-director Aidan Potter suggests that order, though sought, can be stultifying: “Sometimes, the serial decision produces a serial conclusion –the premature diagram that is part of modernism’s failure in urbanism, landscape and housing. Every town and city is littered with failed, if well intentioned, experiments. It can’t be the right thing to pretend it hasn’t happened. We need to rebalance it. Architecture determines space, but people make spaces positive, make them take on a personality. Completely resolved, completely ordered buildings and spaces are completely vacant. They induce a loss of identity.”

And so the practice’s design processes, clearly evident during the Friday design review sessions, are driven by the assumption that buildings should convey a presence not only embedded in modernist formalities and materials, but in a desire to reflect a narrative of architectural and urban spatial engagement.

JMP’s design teams are hardwired by the traditions of an earlier age when architects mined the past for elaborate stylistic references, yet more typically produced clearly assembled civic and industrial locales. And this is one reason why, apart from an impressive portfolio of new buildings and urban masterplans in Britain, Russia, India, and Africa (roughly 100 projects at any one time, half of them “live”) the practice has become preeminent in Britain as modernisers or recasters of important seams of historic architecture.

These projects have ranged from Robert Dockray’s 1846 Roundhouse in London, to Mendelsohn and Chermayeff’s De La Warr Pavilion at Bexhill, and the Swiss Cottage library by Sir Basil Spence. More recently, the practice has been involved in schemes to revivify buildings such as Goldfinger’s Trellick Tower; Stirling and Wilford’s Cambridge History Faculty Building, and the general market at Smithfield.

JMP’s biggest current project, the redevelopment of King’s Cross Station, is an exemplar of cross-practice collaboration, involving specialists from urban design, transport, landscape, commercial, retail, interiors and heritage teams.

Jay Merrick