Work is due to start on site in in January 2024 and is expected to be complete by summer 2024.
A staff boardroom on the second floor will become an amenity for school visits, while new multifunctional learning facilities will host creative workshops, discussions and events.
The gallery’s entrance area, the gallery hopes, will become more of a meeting point and encourage visitors to stay longer, take a seat and browse in the shop.
New heating, lighting and ventilation systems will be incorporated to improve energy efficiency and user comfort.
The culture specialists will carry out a major interior overhaul of the sculpture gallery on the Headrow in the West Yorkshire city.
Completed in 1993 by Dixon Jones, the building is a Leeds landmark with its bold, polished black granite façade.
Sillars added: ‘These alterations will bring a significant step-change to how and where our programmes are experienced, retaining our world-renowned research facilities while ensuring that young people – our potential great creative thinkers of the future – feel at home.’
Inclusive, fully accessible toilets will include changing facilities. A basement seminar room will be given more natural light, new seating and upgraded technology.
The Henry Moore Institute, Headrow, Leeds, designed by Dixon Jones