BG3 houses the board and the faculty office of FGw. The various departments or sections in the faculty office provide support for the primary processes of teaching and research. The building has been designed to accommodate visitors for meetings and discussions.

Additionally, VOX-POP plays a significant role in promoting the visibility of FGw on the ground floor. They organise various publicly accessible events for and by humanities scholars (students and staff). This function attracts a considerable number of people to the ground floor during events. The stage has been renovated to facilitate this. BG3 is a publicly accessible building, hosting visitors and guests for various activities.

The building was renovated in 2021, with a focus on preserving its architectural elements. The building consists of the original Administration Building and the pavilion annexed later. Although the buildings are connected, they have different architectural styles.

Renovation components
The renovation project included the following components:

• One of the challenges during the renovation was to connect both parts effectively. Innovative techniques were employed during the renovation, such as opening up the ceiling of the pavilion and covering it with acoustic spray mortar. Some of the office spaces above have special sound-absorbing round ceiling elements.
• Sustainability measures were also taken to upgrade the existing air control system. Cooling was expanded and heating options were added. As a result, BG3 will significantly reduce its natural gas usage.

BG3 consists of two building sections, both constructed at different times. The most historic section, on the side of Oudezijds Achterburgwal, is the original Administration Building from 1916, designed by J.M. van der Meij. The oval section located on Binnengasthuisplein is a later addition by Theo Bosch from 1995.
The Administration Building consists of a central middle section comprising a ground floor with two additional floors and an attic under a hipped roof. The adjacent annexes consist of two or three stories under a flat roof. The building was connected to the former Children's Clinic, which was demolished and replaced by an annex with a more or less oval layout, comprising a basement, a ground floor and two additional floors under a flat roof.

The Administration Building
The Administration Building was constructed in 1913-1916, based on a design by J.M. van der Meij. Originally, it was connected to the Children's Clinic built behind it. However, the Children's Clinic was demolished in 1991 to make way for a new addition designed by Theo Bosch (1940-1994), which was completed (posthumously) in 1995. In response to public pressure and based on official advice, the government decided in 1982 that it was of vital importance to preserve Van der Meij's design. The building was an early example of the Amsterdam School architectural style, and the visible use of concrete was considered remarkable.
Although the interior of the Administration Building has been largely demolished, the staircase has remained somewhat in line with Van der Meij's design. The exterior, with the exception of a chimney to the left of the facade, has been preserved reasonably well; only the balconies on the corners were modified by Bosch with an addition.

The oval section added by Theo Bosch
The 'new' section of the building consists of an oval layout with open floor plans, where the floors are supported by pilotis (columns). The old and new sections are connected through an open connecting element, within which a footbridge links the second floor of the new section to the old. The interior of the old and new sections has received a similar layout and a similar finish. The new section of the building, as we know it today, largely follows Bosch's original design.

Source: 2019 P. Vlaardingerbroek, Monuments and Archaeology, Municipality of Amsterdam, Description of Binnengasthuisstraat 9, internal document, compiled on February 14, 2019. Contains references to, among others, Monument and Archaeology property files, Amsterdam City Archives, image bank, Central District, Building and Housing Supervision Archive.