British Vogue archivist and editor Robin Muir's deliciously inviting home

They say that, when viewing a property, it can take mere minutes to know whether you want to buy it. It may seem like a blind leap of faith, but your first impression will actually have been informed by myriad things: sounds, smells, the way the light falls. This is how it was in 2002 when Robin Muir (Vogue archivist and curator of the National Portrait Gallery's 2016 Vogue 100 exhibition) and Paul Lyon-Maris first saw their north London house.

Visiting it today, their snap decision makes perfect sense. This house is urban nirvana: a short walk from the Tube, yet hidden down a private lane on the far side of a courtyard planted with cherry trees. With a Victorian brick façade almost filled by a two-storey window, it was built in the mid-nineteenth century as part of a group of artists' studios when land in the area was cheap and Hampstead was still a village. A desire to wrest the title deeds from its owners' hands and move in immediately begins to form.

The covetousness only intensifies once you are inside and step into a sitting room of a volume that is a rare luxury in a city where every square metre matters. A fire flickers within a stone chimneypiece and in the broad, high alcoves on either side of the chimney breast, bookshelves climb towards the apex of the double-height, sloping ceiling. Around the fire, two plump sofas and two stout armchairs offer an irresistible temptation to sink down, kick off your shoes and settle in for a quiet read or a long conversation, while admiring the view of trees, birds and sky through the towering studio window. The gaze wanders across walls of art, including a John Bellany painting over the chimneypiece and a glowing nineteenth-century copy of Pietro Perugino's Sermon on the Mount. You could get very comfortable in this room.

But before you do, it is time to admire the kitchen, which opens off the sitting room through two widely spaced doorways. Here, the ceiling height drops, but the floor space is just as generous. There is a wall of cupboards centred by dresser shelving and a glossy black Aga between the doorways, which is the heart of the room. And here, too, the view from the wide and tall bay window is of trees, looking across a street's worth of long back gardens.

Back into the sitting room and up the stairs, a balcony landing allows a close-up look at a chandelier with a bouquet of wire-caged bulbs. Through a doorway there is a small inner landing, a pair of adjacent bathrooms - one with a shower, one with a bath - and the bedroom, which is above the dining end of the kitchen and enjoys the continuation of its bay window.

The architectural feel is Arts and Crafts, a suitably robust and plain background for antiques, Celia Birtwell printed linens, and the twentieth-century British art that the owners collect. 'It couldn't have been more different when we bought it - all little rooms with fitted carpet,' says Paul. 'We needed help to change it. The late actor Alan Rickman, who was a friend, recommended Caroline Holdaway, who had done a house for him. He told us she really listens.'

So began a relationship that has flourished through the subsequent remodelling and decorating of Robin and Paul's house in Sussex (featured in the October 2014 issue of House & Garden), the complete renovation and decoration of this house, and also the recent 'dolly-up', as Paul calls it. Although Robin, as former picture editor of Vogue, might seem to be the obvious interiors enthusiast, it is theatrical agent Paul who is passionate about interior design. 'Collaborating with Caroline is such a pleasure,' he says. 'She has wonderful colour sense, but she is also immensely practical and does all the legwork.'

In Sussex, Paul and Robin have horses and dogs, and house guests with children. But when in London, they live a different life, not entertaining at home as much, eating out and using the house as a retreat. Working with the architectural technologist Mike Etchingham, Caroline reordered the space. Even the roof came off, as dividing walls were taken out, a new staircase and landing were put in, and the double-height bay window at the back of the house was added, bringing light and extra square metres to the kitchen and bedroom.

'It's the most lovely house to wake up in,' says Paul. 'We never completely lower the bedroom blinds, so we wake up with the light. In spring, the views are of blossom, in summer of leaves, in winter the sky'.

Caroline Holdaway Design: 020-8341 6525; Etchingham Morris Architecture: 01425-483155