Following the death of Robert Venturi, Charles Holland reflects on the American architect's career of revered research, trailblazing projects and witty demeanour.

If Robert Venturi had only written Complexity and Contradiction in Architecture, his place in the history of architecture would still be assured. Along with Le Corbusier's Towards A New Architecture, it is one of the two most influential books written by a practicing architect in the last 100 years.

Its publication in 1966 reshaped architecture, opening up what had become a sterile conversation around modernism into a re-engagement with history, ornament, decoration and, yes, complexity and contradiction. Its concepts and aphorisms – such as The Difficult Whole and Less is a Bore – have entered the architectural vocabulary and influenced countless architects.

But Venturi also co-authored Learning from Las Vegas, along with his wife and partner Denise Scott Brown, and Steven Izenour. Less a "Gentle Manifesto" than a radical punch to the profession's solar plexus, LFLV challenged architects to take popular culture, popular taste and ordinary architecture seriously. It was also a highly divisive book that many saw as uncritical and overly accommodating to the more extreme forms of capitalism.

It set the tone for Venturi's status as a highly respected and hugely influential architect who was also a professional irritant and, somehow, an outsider. Given his love of difficult reconciliations and perverse contradictions, this status was entirely appropriate.

Venturi was almost alone amongst contemporary practicing architects in articulating a coherent theoretical position. His work – undertaken with a number of partners but for the longest period with Scott Brown – embodied and advanced this position. His first major work, one that shifted architecture's centre of gravity, was a modest house in Chestnut Hill, Philadelphia, for his mother, completed in 1961. It is known as the Vanna Venturi House or, more simply, Mother's House (main image).

Learning from Las Vegas set the tone for Robert Venturi's status as a hugely influential architect

It is an extraordinarily rich and fertile piece of architecture. It breaks any number of modernist rules. It employs explicit decoration. The elevations aren't a pure expression of internal requirements. It is almost, but not quite, symmetrical. It is painted green in defiance of Marcel Breuer's dictum that architecture could be any colour but that.

And it looks like a house, in the obvious and elemental way. And yet it is far from obvious or reductive. It is rich with allusions and taught with ambiguity. It is playful and strange and familiar and deadpan, somehow all at the same time.

When I visited the Mother's House I was struck by how modernist the interior was, almost Corbusian but with a whole load of other things going on too. Modernists should love it. It employs collage and cut-ups, dissonance and disjunction. It has learned from Marcel Duchamp and Kurt Schwitters as well as Alvar Aalto, Adolf Loos and Edwin Lutyens. It has it all, squeezed into one phenomenally tight little package. It made Venturi's name and undoubtedly – for better or worse – launched postmodernism.

Venturi himself described his Mother's House variously as classical, mannerist, even modernist – but very rarely, if ever, postmodernist. He disavowed the movement he spawned and – in an echo of the McCarthy-era witch-hunts – claimed: "I am not, nor have I ever have been, a postmodernist". His intellectual desire not to be pigeon-holed and to allow for different readings and interpretations was typical of his seriously playful spirit.

Venturi went on to design a serious of brilliant residential projects: the art-deco inflected Brant House in Connecticut (1970), the tall tower-like Tucker House in Westchester (1974) and the beautiful house in Delaware (1978). Each one negotiated a line between the aspirations of architecture and the contingencies of everyday life, developing a repertoire of forms and devices of great subtlety.

Vanna Venturi House is an extraordinarily rich and fertile piece of architecture

Venturi Scott Brown Associates designed a number of important public buildings too: the pure pop architecture of Fire Station Number 4 in Columbus, Indiana (1966), and the urbane arts-and-crafts-inflected Gordun Wu Hall on the Princeton University campus (1980) amongst them. Gordon Wu was the first in a series of richly patterned but formally generic "loft" buildings that took the practice's concept of the "decorated shed" and applied it to the university campus.

VSBA designed only one building in the UK, the notorious Sainsbury Wing of the National Gallery, completed in 1991. This building has been unfairly tainted by an association with Prince Charles' condemnation of a previous scheme for the same site. Looked at in its own right it is a love letter to London written in stone, a tribute to Bob and Denise's heroes: John Soane, John Nash, Lutyens and others.

It is contextual in the most interesting sense, playing off against its neighbours in ways that are both cheeky and respectful. And as Scott Brown has said, it recognises its role as a backdrop to the events of Trafalgar Square.

Scott Brown's input and influence on the practice has been immense. Ingrained industry sexism has undoubtedly downplayed her part, most evident in her exclusion from the Pritzker Prize, which was awarded to Venturi alone in 1991. But it was Scott Brown who introduced Las Vegas to the mix, and who brought an engagement with popular culture, sociology and urbanism. Her pioneering interest in advocacy planning and community engagement also gave a political and social dimension to the work.

Together the couple were invariably referred to affectionately as "Bob and Denise". Their office in downtown Philadelphia was charmingly messy. Their beautiful art-nouveau house in the suburbs was a test-bed for ideas.

Scott Brown's input and influence on the practice has been immense

Its interior is a treasure trove: choc-full of books and artefacts, translations of Learning from Las Vegas in every conceivable language, toys from Japan – a country they both loved – McDonald's signs, neon lights, pop artworks, eclectic furniture and rich decoration. It is a testament to a life that has combined teaching, writing and practising architecture at the highest possible level.

He was consistently kind and supportive of the work by FAT, the former studio I co-founded with Sean Griffiths and Sam Jacob. Occasionally he would send post cards and books, invariably signed-off with a witty aphorism or a back-handed compliment. "Dear fellow perverts and degenerates", he wrote once; "please keep up the bad work!" Like his designs, one had to fight one's way through a dense thicket of contradictory meaning to find the truth at the heart of it. But it was more rewarding that way.

Venturi opened my eyes to architecture. Through him I learned to love not just Las Vegas but classicism, mannerism, the baroque, Lutyens, Aalto, Wright, Loos and others too. The tension and aesthetic thrill of great architecture and an appreciation of the beauty of ordinary things were made available to me through his work.

The one architect-designed house I would truly want to live in is the Trubek House, the shingle-clad cottage he designed on Nantucket Island in 1970. It is all there in that little house: all of architecture. Venturi was an immensely talented architect, a brilliant writer and a warm and witty man. RIP Bob.