Desig House: Real Homes: Rita Konig's London flat

Interior designer Rita Konig is known for her strong ideas about decorating but when her own household expanded, she had to rethink her plans for her west London flat

Rita Notes | Style File: Rita Konig | Modern Manhattan house designed by Rita Konig

Rita Konig is not a woman who is afraid to speak her mind. Reassuringly opinionated on anything from cut-pile carpet (loathsome) to kitchen sinks (should never be visible from the sitting room), she administers her __design dictums with a confidence and certainty quite at odds with her easy-going, almost girlish manner. She is at once a style commentator - as European editor for T: The New York Times Style Magazine - and a __design agony aunt, dispatching regular, compulsive decorating advice to readers of House & Garden through her column, 'Rita Notes'. The daughter of design royalty Nina Campbell, she has been brought up on good taste, and is herself a decorator in high demand on both sides of the Atlantic, with current projects including a US hotel refit and a London townhouse.

In a new venture, she has started hosting workshops from her home in west London, inspiring groups of paying guests with her own blend of design wisdom, instruction and sourcebook secrets. A perfectly natural departure for this mine of maxims, the workshops use her garden flat as an example of how to get it right.

Returning to London from New York in 2012, having spent six years there honing her signature crisp-yet-cosy decorating style, Rita originally intended to create the perfect home for herself as single girl about town. On buying the flat, she set her mind to remodelling its interior to house a small kitchen and large entertaining space. 'The whole thing seemed to take forever,' she says, curling her feet under herself on a vintage sofa covered in crimson velvet. 'But just after I moved in, I met Phil [the biographer Philip Eade], and then I was married and pregnant. I just couldn't face moving again, so the first call I made was to the woman next door to ask if we could buy her flat.'

After months of negotiations, the sale went through, the builders went back in, and a lateral conversion, which created space for a further two bedrooms and a dressing room, was completed. The couple moved in in November 2014, with Margot, who - fast asleep during my visit - had been born the previous February.

'We did what we could in a short time,' says Rita of the lateral conversion. 'We have everything we wanted. I love sitting here and looking out at the garden. It gives you such a sense of space and the more I go to other people's houses, the more I think that lateral is the way we ought to live. People are spending so much money on these vertical houses. I have friends with houses worth millions and they spend their whole time in the kitchen in the basement. Not having stairs when Margot was crawling was amazing. It was like being in an enormous hotel suite, where no one has to go downstairs in the middle of the night to get the milk.'

Visitors to Rita's flat must enter from the street through a door into an unexpected and exquisite garden (she describes her bed of box balls as one of her 'best investments'). 'It was when I realised that I could give this flat its own entrance through the garden that the property started to get exciting,' she says. When living in New York, all her apartments opened straight into the kitchen and she wanted to continue the look in London. 'This seemed to work very well coming off the garden, just like houses in the country where there is almost always a door to the garden from the kitchen. And it is very jolly for when people come over for dinner, and when arriving with shopping bags.'

Friendly and remarkably practical, the small kitchen has very simple, Corian-topped units designed by Rita, and functions as a buffer between the street and the cocooning comforts of the rest of the flat. Up a small step and we are in the open-plan dining and sitting room, the kitchen neatly out of sight but within easy reach. 'I find the kitchen - and where people choose to position it in a house - very interesting,' Rita muses. 'Women, having spent years fighting their way out of them, are now manacling themselves to these enormous kitchen islands, while their children sit in the drawing room playing computer games. I still have a sense of open plan without ever having to look at the kitchen sink.'

Both the sofas in the sitting room are surrounded by intense collages of framed pictures and prints. Behind, a passageway leads to the more intimate parts of the flat: a bathroom hung with palm-leaf 'Martinique' wallpaper from Hinson, a spare room and study, a dressing room and, ultimately, a serene main bedroom with an adjoining nursery.

Masses of walk-in storage space, plus an enviable laundry and additional bathroom in the basement, make this a highly functional, enviably modern family home. 'If you don't have good storage, your life is a mess. It is expensive, and people don't like to put it into their budgets, but it's crucial,' says Rita. When asked how she did it all, she reels off a long list; this includes losing 12cm off the length of the sitting area to make room for the full-length bath in the bathroom and buying land from fellow freeholders to extend the flat into the garden to make room for the dining area.

In short, this is a meticulously planned and carefully executed project. Rita shrugs at the compliment. 'What I am interested in is how you live in a space, and how to be comfortable. I am constantly striving to create that comfortable room that I once stayed in, and often it's as simple as wanting to sit down and have somewhere to put your drink and a light to read your book by. It has been interesting decorating for myself as I don't do it in the same way that I do for clients, where I make a presentation and work it all out. Things have just sort of appeared and the space has evolved.' And, as if on cue, Margot is awake and my decorating masterclass makes way for lengthy negotiations about her lunch.

Taken from the March 2016 issue of House & Garden.