20 Carlton House Terrace

A garden vision for The Mall
20 Carlton House Terrace © Altius
Inspired by John Nash's historic Carlton House Gardens, a series of new garden terraces and courtyard gardens will provide improved urban greening and public realm improvements adjacent to The Mall.

Carlton House Terrace is within a highly sensitive heritage context, in St James's conservation area, situated between Grade I listed St James's Park and Trafalgar Square. Carlton House Terrace and its extension, Carlton Gardens, was built during the period 1827-1833. The development was designed by John Nash and included three ornamental garden squares all known as Carlton House Gardens, opposite the grand Carlton House Terraces.

The design proposals are inspired by this heritage Nash setting, to provide a series of garden terraces, garden courts and public realm improvements to repair and improve the context in which it sits.

The landscape and public realm improvements seek to work within the tight urban grain, challenging existing subterranean utilities/services and a varying microclimate across the site. A series of roof gardens and landscape terraces will provide a verdant outlook to neighbouring properties and the reconfigured building footprint by RSHP, to provide meaningful wellbeing for residents and office workers.

New street trees are proposed within a wider future public realm improvement strategy, to upgrade pavements and spaces to improve the permeability of the site, to provide green infrastructure, landmark links and legible walking routes from Trafalgar Square to The Mall.
Close coordination with City of Westminster tree officers enabled a positive discussion on the climate resilience and future planning of tree cover, with a proposed planting palette to thrive within varying site microclimates to provide an increase in biodiversity and new ecological habitats.

20 Carlton House Terrace, St James's, London


Altius Real Estate / The Crown Estate


0.4 Hectares


Planning approval, Concept Design to Tender, Construction monitoring


Architect: RSHP (Rogers Stirk + Harbour Partners)
Architect: EPR Architects
Structural and Civil Engineer: Elliot Wood
M&E Engineer: Hoare Lea
Quantity Surveyor: Core Five
Highways: Transport Planning Practice
Soils: Tim O' Hare Associates

Image Credits:

Altius Real Estate