Panoramic House is a large detached house in the Reddington & Frognal conservation area of Hampstead. The house benefits from a large South facing garden screened by mature trees on all three sides. Our client, a family with teenage children, approached us to extend the lower ground floor to create more living space and a better connection with the garden. The site naturally slopes down to the rear. Extending into the garden presented an opportunity to drop down and become immersed in it. One of the main challenges in developing the design of the extension was working with the constraints of mature trees in nearby proximity. We worked closely with arboriculturists to establish the extent of tree root protection zones and these have influenced both the footprint of the extension and the lower floor level within and adjacent to the extension. The result is finely calibrated to avoid damage to the nearby trees.