Designers and architects were asked to take into account the following brief before submitting expressions of interest.

Size and scope
Designers will need to consider the views of the adjacent residence of the Foreign Secretary (to the west) and Carlton House Terrace (to the east) which overlook the site. Size and scale are important, to ensure that the memorials have sufficient presence whilst being sympathetic to the surrounding environment.

Materials
Any materials proposed for the site will need to be sympathetic to those already existing in the area, including Portland stone, granite, bronze and cast iron. The new memorial should be constructed of permanent, high quality materials which will be suitable for the London climate. Ease of ongoing maintenance by The Royal Parks is a key issue, so the use of water and moving parts is to be discouraged. Planting schemes should similarly be low maintenance in nature.

Costs
The target cost of the scheme is £1.2 million, excluding fees and VAT. Designers will be encouraged to propose schemes which have a lower cost.