Designer Willow Kemp's joyful Chelsea flat

'I greet most people slightly out of breath after they have climbed the stairs to the top of the building,' says interior architect Willow Kemp of her joyful flat in the upper reaches of a converted building dating from 1884, in the Park Carlyle Conservation Area of London's Chelsea. 'But I always love the look of surprise on their faces when they arrive!'

Visitors also comment on how spacious it feels. Willow - an art ambassador for her family's Firmdale Hotels and design director at Kit Kemp Design Studio - has managed to claim an extra 0.6 m (2 ft) in ceiling height by opening up the loft space. Decorated with the flair of an artist and the know-how of a top designer at the cult hotel brand, the flat combines her passion for collecting contemporary art (some of it fresh from graduate shows) and fascinating objects with a technical understanding of architecture. Injected with Willow's love of colour and pattern, the flat deploys all the practicality, space-saving tricks and sense of occasion of a well-conceived hotel suite, balancing the owner's precision and spirited personality. This means that in a smallish space there's room for a dining table for six; the bed is jump-up princess height; and the compact kitchen/hallway is functional and stylish enough to be in full view.

Willow's home is fresh and liveable, with artworks that tell a story of her trips, interests and life. A connective creative thread runs through all the spaces. The rug in the living room, for example, was the inspiration for 'One Way', a fabric design that she worked on for Kit Kemp's collection with the textile and wallpaper designer Christopher Farr, and which is on the walls in the entrance and up the staircase. The attention to subtle detail - pops of coloured piping, contrasting leather and a handle at the top of dining chairs, studding on furniture where two materials meet - brings added interest.

The building was originally artists' studios occupied by landscape painters, and has a distinctive Arts and Crafts appearance, being constructed from red brick with white stucco decoration to the entrance portico. 'My flat on the top floor has a beautiful, large, full-width bay window to the east and vertical sash windows to the north and south, making it especially light and airy,' explains Willow. 'I love how you feel in touch with Chelsea's past, when there was a concentration of artists' studios.' In the bedroom, she often paints at a 19th-century rosewood heirloom desk with delightful cardboard lamps by Biarritz artist Mimi Chanard and a view of Chelsea beyond.

The flat is a place for Willow to display her various collections so that the pieces have a dialogue with one another, giving the space character, energy and soul. 'When I come home from a long day at work,' she says, 'I love to open the door to my happy home. I often sit at the window seats I made by extending the windowsills and adding a tailored cushion. I'm up in the eaves, so the curtains swing back and are lined with a ticking fabric. I can peer over at the south-facing leafy gardens or into my open-plan living room and kitchen filled with light from the original studio window.'

This is an expanded extract from ‘All Things Considered: Thoughtful Interior Design that Mixes Pattern, Colour and Style’ by Emilio Pimentel-Reid (Hardie Grant).