Fraser Bond are the leading lettings and property management agents for Marylebone House - London NW1. Marylebone House at 129-137 Marylebone Road is a proposed commercial development in Marylebone, London NW1. Approval is sought for three additional storeys to the existing 1960s building which would seek to create a better transition to the retained 1930s building. Proposals also include demolishing the redundant car park to the south of the site and introducing new office space in a mews block. Location The site is in Marylebone bounded by Marylebone Road to the north, Wyndham Street to the.