Rita Konig has subtly enhanced the airy interiors of this Manhattan house

It did not look like a match made in heaven: two people with diametrically opposed tastes. And how risky, when the two people are the owner of a house and the interior designer hired to work on it. 'Thank goodness I didn't have my website back then,' says designer Rita Konig when discussing the house in New York. 'She might have taken a look and gone, "This isn't for me.' Rita is a self-professed lover of 'clutter and pattern', but the American owner, a documentary film-maker, describes herself as 'a clean-lined minimalist'. Her parents are Scottish and Danish and she grew up with elegantly spare Scandinavian furniture. 'Beautiful to look at, but not very comfortable,' she admits.

The pair first met through the English writer Plum Sykes, who was then working for American Vogue, before working together on the house bit by bit for nearly a decade. 'It is often more fun to work with someone whose style is completely different to your own,' says Rita. 'It's the people who say, "I love your style" who often don't really know what they want. Also, they probably don't really like your style and are just too embarrassed to say no.'

This owner found saying 'no' easy. She has very definite taste, but just did not have the time, patience, furniture or inclination to sort out the interior of her 420-square-metre home in New York's Greenwich Village. She, her husband and their three children had relocated in 2007 from a smaller apartment nearby and she admits to having been totally flummoxed by the scale of her new place. 'I was very tempted to just fill it with a lot of spare leather furniture,' she jokes.

It was love at first sight when she saw the house - a classic 1899 four-storey brownstone that was only on the market for a day before she and her husband snapped it up. It is built like a giant layer cake with two bedroom floors (the children are at the top of the house and the adults a floor below) and two living floors (the high-ceilinged sitting room floor with its three giant windows and underneath that a spacious kitchen-living space that opens onto the garden at the back). For the owner, the important thing about the house is how it makes her feel - 'like living in a country house'. The sitting-room windows look out onto a verdant south-facing garden, which is 'very serene and quiet. You don't feel like you are in New York'.

The previous owners were French and had impeccable - if somewhat formal - taste. The current owner, who grew up in France, admired their style and also the structural changes they had made, such as the slim spiralling staircase, arched windows and hand-painted beams in the kitchen-living space. In many areas, like the kitchen and the main bathroom, she did not feel the need to change much, if anything. But she knew that she needed help buying furniture and pulling the interior together.

When Rita arrived, she immediately found the interior plan verging on stark. The owner had warned her that she did not want pattern, but Rita thought this was negotiable. To soften up the austere main bedroom, with its grey faux panelling, she upholstered the bed in a delicate two-tone Italian fabric by Idarica Gazzoni. The pattern is then repeated on a sheer window blind. The owner was pleasantly surprised. Emboldened, Rita introduced a mauve-grey Luke Irwin rug, which she describes as 'like a sky with streaked clouds that were dragged by a comb'. But the rest of the room is monochrome. Rita upholstered the chairs in simple grey linen, because, she says, 'I had used up my pattern ration at that point'.