The structural systems of the existing City Hall and Former Supreme Court buildings suggest attenuated space. This project builds on the latent attenuation to articulate extended galleries, knitting the two buildings and new construction together into a seamless flow of single-, double-, and triple-height spaces.
The notion of attenuation informs the spatial, programmatic, and tectonic nature of the National Art Gallery.
Entries are kept at the front of the two existing buildings. These main entries serve as the ends of the circulation loop. The Former Supreme Court entrance immediately connects vertically to Level 5 under the dome and over to the City Hall roof galleries. The main City Hall entry on Level 2 brings the public to the interior courtyard and between intersecting double-volume gallery spaces. An entry from a side street to the ground level of City Hall provides public access to the courtyard space and up to the Level 2 main foyer as well.
Double-height galleries interlock and overlap with single-height galleries, serving as links along the courts. The spatial structure of the existing City Hall is kept and heightened with the elongated gallery spaces. The existing floor plate is removed in four spaces along the courts to allow for larger works and provide spatial flexibility in linking to other galleries.
Smaller single-height spaces are perpendicular and connect to the double-height spaces.
The Roof gallery serves as a loop between the two buildings, expanding the gallery as a continuous space over the existing City Hall and into the Former Supreme Court. Translucent roof and walls at this level are screened by light fins and scrims. A mechanical plenum between the roof gallery and the existing building below serves galleries.
The attenuated gallery sequence provides four specific links between the two buildings: continuous below-grade commercial space, an exterior public link at the ground level, and two bridges at level 5 that act as continuous gallery spaces intersecting with the front and rear of the Former Supreme Court.
The two existing courtyard spaces are reclad with translucent walls to form an integral part and extension of the roof envelope into the existing building. These courts allow broad areas of diffuse light into the double- and single-height galleries at the perimeter. The ground of one court serves as an attenuated threshold and entry into the middle of the existing City Hall. The other existing court has a glass bottom, allowing light into the lower level.
A new court is formed in the street between the two buildings by the bridges overhead at Level 5 s – it has the same proportion as the existing interior courts, but is part of the public realm. This court allows for the space between City Hall and the Former Supreme Court to be activated by the public and, in turn, integrate the previously separate structures.