Mix and max: Designer Max Clendinning has had a radical change of heart when it comes to minimalism

There was a time, in the 1960s, when the architect, furniture and interior designer Max Clendinning (below) would have liked to have done away with "stuff" altogether. "When I started out, I didn't like objects, strangely enough. In 1965 I had the idea of eliminating furniture altogether – making rooms [where] you could sit on the floor, very minimalist," he explains. He created all-white sculptural spaces, and clear rooms populated simply with enormous, squashy, slug-shaped sofas to lounge on or lean against.

This is surprising for two reasons. First, Clendinning is today best known for the slot-together but sturdy looking Maxima range of chairs (see pictures overleaf), which he designed in 1965 and which feature in a new V&A exhibition of modern design icons. The chunky, k geometric shapes with their corners curved off are both very much of his style and of their time: "They were inspired by, at that time, what we called computer lettering. There was chinaware from Germany called Thomas stacking china – there was a lot in the air, of that feeling [of neatly slotting things together], to me." He still uses a full set of the chairs around his own dining-table today.

The second reason his disliking of objects seems implausible is that I'm interviewing him in his Victorian terrace house in Islington – and it is packed to the rafters, often rather beautifully, with everything from Memphis glass to mid-century Aalto furniture to William Morris prints to Picasso plates... not to mention the vast array of the 87-year-old designer's own, very varied, pieces, be they those chunky modernist chairs, an esoteric sculpture or a trompe l'oeil ceiling painting.

Clendinning has lived here with his long-term partner, Ralph Adron, since 1972. Adron worked as a stage designer and his hand is also clearly visible: he created an astonishing mirror which seems to sprout antlers, sewed the abstract, painterly needlepoint on a pair of chairs in their front-room, and painted the strong swirly patterns in both his own study and across their mantelpiece. "We never disagree," says Clendinning rather sweetly. "I admire what he does, and he admires what I do."

But such a frenetic bricolage of styles and eras could easily just become a postmodern mess. Not so here; stepping into Clendinning's home is like entering a slightly magical space, or taking a bit-part in a fantastical play designed by Adron. Indeed, explains Clendinning, "Originally, I thought of the interiors I designed as an oasis from the world outside." Not with the aim to block the world out, you understand – although he does also have some adorable shutters, in gold gilt upstairs and silver downstairs, which would do the job elegantly – but rather to create another world within. And while the rooms might be busily decorated, there is certainly a method there, a tone and style carefully created. And mostly, that method is colour.

"The way [the pieces are] related is virtually always with colour – all that's quite happy there, because of the colour, although it's in a Victorian house," he says of a little set-up in the front-room. It combines the gold-dripping mirror of Adron's, Clendinning's first ever attempt at sculpture – a yellow squiggle of a thing he made in 1950 – and a stone Buddha they rescued from Adron's father's garden, all set against the watercolour wallpaper Clendinning made himself, (it was "layers and layers of colours, blue underneath, and yellow and white, but put on completely wet" he elucidates).

In other rooms, yellow is definitely the dominant note – a long-time favourite shade of Clendinning's, daffodil-yellow is splashed around his study on the doors, in the tiled fireplace, on the other side of those blinging shutters. Also in his study hangs a large colourful cloth piece by Natalie Gibson, textiles professor at Central St Martins, and in front of it stands an enormous papier-mâché tulip. It's been a fixture in their lives since Adron made it for that white room in the 1960s.

It's hard to imagine Clendinning exploring space-age minimalism, given the current riot of colour in his home. The closest thing to it is a little studio space they created in what was a closed-up loft when they moved in. "It was just a dark space and I saw the possibility of reworking the room and the terrace outside. It's nice to be able to get the sky – there's wonderful views on the city," he says. Which is true: rising above the rows of neat terraced roofs, far in the distance, you can make out the Shard.

This attic area has a few of Clendinning's more recent designs (the chairs are about five years old) and while he doesn't do professional projects any more, there are various sculptures he makes for his own enjoyment dotted about the place. On the back gabled wall is a cabinet he made years ago, specially for the space – which, he reveals with a smile, contains a sink and swivel-out tap behind a couple of dinky hatches. This is so he can water plants on the terrace, wash his brushes and make a cup of coffee in a marvellously surreal coffee pot by Italian designer Gaetano Pesce.

As with the rest of the house, there is a degree of artful maximalism here: the items have form and function, but they are also expressive, personal, and don't necessarily sit together in obvious ways. Maybe what Clendinning and Adron have actually perfected in their unusual home is miximalism. And it comes as no surprise that Max knows how to find just the right mix.

British Design 1948-2012: Innovation in the Modern Age is at the V&A (vam.ac.uk) from 31 March to 12 August