Robin Day: Designer best known for his Polypropylene stacking chair

Furniture designer Robin Day, who has died at the age of 95, lived to become a legend in his own lifetime. Day created the world's first Polypropylene chair, fondly known as the "Polyprop", one of the best-selling stacking chairs of all time – 14 million and counting – widely used up and down the land in schools, cafés and village halls. Originally launched by Hille in 1963, it is still going strong in various forms today, literally so, as it is remarkable for its durability as well as its understated visual sophistication.

Day's choice of career was shaped by his upbringing in the furniture-making town of High Wycombe in Buckinghamshire. Born on 25 May 1915, he grew up surrounded by timber yards and cabinet-making workshops. Recognising his drawing skills, his parents enrolled him as a junior day student at High Wycombe Technical Institute, which was closely allied with the local furniture industry.

Throughout his life he loved working with his hands. During the war, when furniture was in short supply, he constructed his own chairs, tables and storage units, using whatever materials he could lay his hands on. His workshop became an essential adjunct to his design studio, as it was here that he fine-tuned the models for his production furniture. Minutely concerned with every technical and ergonomic detail, his approach to design was always very direct and hands-on.

In 1931 Day progressed to High Wycombe School of Art and from here to the Royal College of Art in 1934. Although the RCA proved disappointing as it was simply not geared up to teach industrial design at this date, Day used his time to good advantage, further developing his already excellent drawing skills, poring over architecture and design magazines, and haunting furniture showrooms and exhibitions. In spite of his prodigious talents, when he left college in 1938 there were no obvious openings in the furniture industry, so initially he made models for architects. The outbreak of the war did not improve his prospects. Ruled out from active service by asthma, he taught at Beckenham School of Art, where he devised an innovative course in three-dimensional design.

In 1940 he met a beautiful young textile designer called Lucienne Conradi at an RCA dance. Although they came from very different backgrounds, they hit it off immediately as they shared a mutual passion for modern design. Following their marriage in 1942, the Days set up home in a flat in Chelsea. Ten years later, by a stroke of good fortune, they bought a tall narrow Victorian house in a prime spot on Cheyne Walk, their home and studio for the next five decades. Lucienne Day, who died last January, went on to become Britain's most celebrated post-war textile designer. Their daughter, Paula (born in 1954), inherited Robin's love of hill-walking and his tall, lean, athletic physique.

Shortly after the war Day began teaching interior design at the Regent Street Polytechnic (now the University of Westminster). Here he met the architect Peter Moro, and in 1946 the duo formed a partnership to design exhibitions, mainly for the Central Office of Information, on subjects such as jet engines and scientific instruments. In 1948 they collaborated on an exhibition about atomic energy, which toured the country on a train. Although not trained as a graphic designer, Day had natural talents in this area, which led him to design posters, including an impressive series of recruitment posters for the RAF. He and Moro remained friends and collaborated again later on the Royal Festival Hall in 1951 and Nottingham Playhouse in 1963 (Day designed the seating for both). Day continued designing exhibitions independently throughout the 1950s, working for two major industrial clients, ICI and the radio and plastics manufacturer EKCO, for whom he created a series of impressive trade stands.

His career as a furniture designer received a major boost in 1948 when he and Clive Latimer (a colleague from Beckenham School of Art) won first prize in the International Low-Cost Furniture Competition organised by the Museum of Modern Art in New York, with an ingenious design for multi-purpose storage units. From the outset, Day's primary concern as a designer was the marriage between functionalism and technology. Throughout his career he resisted the lure of fashion, disapproving of designers who worked on purely superficial stylistic lines.

As a result of winning the MOMA competition, which attracted 3000 entries from leading designers all over the world, Day was invited to design furniture for S. Hille & Co. At that date Hille was a small cabinet-making firm specialising in high quality reproduction furniture. At Day's initiative – and with the support of Ray Hille, her daughter Rosamind and son-in-law Leslie Julius – the company underwent a complete transformation and began to produce modern furniture. A range of moulded plywood stacking chairs and tables called Hillestaks were the first designs off the production line in 1950, followed by Hilleplan storage units in 1952.

Day's professional standing was greatly enhanced when he was commissioned to design the seating for the Royal Festival Hall in 1951. Always keen to explore the potential of new materials, he co-opted manufacturing techniques from the car industry for his steel-framed auditorium seating, still in use today. His orchestra, restaurant and foyer chairs combined spidery steel rod legs with sculptural curved plywood seats. Day was the first designer in Britain to exploit these materials in furniture. By comparison with their clunky forebears, his chairs seemed to float above the ground. These chairs, along with some modular storage units, were displayed in two room settings he created for the Homes and Gardens Pavilion at the neighbouring Festival of Britain.

The Festival acted as a high-profile platform for introducing his pared down "Contemporary" aesthetic to a wider public. Architects were particularly enthusiastic about his designs, which were ideally suited to the airy, functionalist style of architecture adopted for public and commercial buildings after the war.

Day worked furiously for the rest of the decade, greatly expanding the range of furniture produced by Hille, and pioneering technical innovations such as the use of rubber webbing and square section tubular steel. By 1960 Hille's catalogues (which Day designed, along with the company's stylish new logo) featured an extensive range of "Contemporary" furniture for office and domestic use. Flexibility and economy were the hallmarks of his approach, typified by his elegant Single Convertible bed settee, which won the first of several Design Centre Awards in 1957. Interplan, a multi-functional, space-saving modular storage system, which dispensed with the need for separate sideboards, bookcases and desks, embodied his philosophy. Heavy-duty public seating was another of his specialities, starting with his elegant but durable British Rail bench (1956) and continuing until recently with his perforated steel Toro seating for London Underground (1990), another deservedly ubiquitous design.

His pioneering early post-war achievements were to a certain extent eclipsed by the phenomenal success of the Polypropylene chair. As the first (and arguably the best) plastic shell chair ever created, it was a landmark in modern design. Cheaper, lighter and tougher than plywood, or any form of plastic on the market at the time, injection-moulded polypropylene proved to be the ideal material for budget furniture. Day took full advantage of its unique properties, devising a masterly and comfortable solution with ingenious structural and technical details. The original stacking chair was followed by an armchair version in 1967. In 1971 he created the graduated tots-to-teens Series E school chairs, followed by the indoor-outdoor Polo chair with its distinctive drainage/ventilation holes in 1975. The Polypropylene chair family was also adapted for stadium seating, and by the 1980s Day had emerged as an international specialist in this field. He also experimented with other plastics during the 1960s and 70s, as well as continuing to refine his designs in wood and steel.

Strong-willed, earnest and tenacious, Day always relished a challenge, be it climbing death-defying rock faces (although in 1963 he experienced a near-fatal fall), or undergoing seemingly impossible feats of physical endurance. An enthusiastic mountaineer and long-distance country skier, he was deeply interested in wildlife and immersed himself in the natural world at first hand at every opportunity. He remained extremely active in later life. In his 60s he spent 12 weeks trekking across the sub-Arctic wilderness on Nordic skis as part of the team led by the eminent ski mountaineer Alan Blackshaw, a remarkable journey of 2500 kilometres through Lapland, Finland, Sweden and Norway. His passion for rock climbing took him all over the world, from the Alps and the Himalayas to the mountains of Morocco and Anatolia. His proudest achievement was conquering Mount Kenya – over 17,000ft and one of the most technically challenging peaks in the world – at the age of 76.

Always interested in projects that tested him in new ways, he brought the same tenacity to his design work. In 1964 he designed the wooden dining hall and library furniture for Churchill College, Cambridge, but his largest and most demanding commission was at the Barbican Centre, completed in 1981. This massive project, which occupied him throughout the 1970s, included seating for five auditoria, as well as the foyers. Apart from Hille, his two other main industrial clients were Pye, for whom he designed radios and televisions from the late 1940s onwards, and the carpet manufacturer Woodward Grosvenor, for whom he created bold, abstract-patterned carpets from 1960-66.

Although they shared a studio and supported each other in their work, Robin and Lucienne Day were both fiercely independent. They only worked together on two occasions, as joint design consultants to the John Lewis Partnership and BOAC. For BOAC they designed interiors for Vickers and Boeing aircraft during the 1960s. At John Lewis they played a key role behind the scenes for 25 years between 1962 and 1987, overseeing the introduction of a comprehensive new house style. Day also designed the interiors of several Waitrose supermarkets and John Lewis department stores, notably Milton Keynes in 1979.

During the late 1990s Day's work was championed by Tom Dixon, the creative director of Habitat. Their reissues of his earlier designs triggered off a new wave of interest and appreciation. With the Millennium came new commissions from SCP, twentytwentyone and the Italian firm Magis. In 2001 the Days were jointly celebrated in a major retrospective at the Barbican Art Gallery, Robin and Lucienne Day – Pioneers of Contemporary Design. I curated this show and wrote the accompanying book recording their life's work, which will be reprinted again by Mitchell Beazley in a few months' time.

At the Barbican exhibition opening, Day looked fit and handsome, defying his years and vowing never to retire. His last public appearance was in September of this year when he attended the premier of a new documentary film called Contemporary Days at the Royal Society of Arts – yet another auditorium enhanced by his own seating. His chairs and benches are all around us – on station platforms, in schools, colleges, concourses and sports halls. They may be largely taken for granted, but that is only because they function so well.

Lesley Jackson

Robin Day, designer: born High Wycombe, Buckinghamshire 25 May 1915; married 1942 Lucienne Conradi (died 2010, one daughter); died 9 November 2010.