3 msmonro.co.uk: Chelsea-based, this is Britain's longest-established interior design consultancy, will design gardens as well as homes. 4 ashtonhousedesign.co.uk: Seven-person design consultancy with large showroom in Ashburton, Devon. 5 fisherid.com; Kent-based with 30 years of experience in high-end residential interior design. 6 suzannetucker-interiors.com; Has handled very high-end London and south east residential design.