16 Rue de la Loi / Wetstraat, Official residence in Royal Quarter, Brussels, Belgium

16 Rue de la Loi is a neoclassical building of pale grey stone, built 1782–1784 by architect Louis Montoyer as a refuge for the Abbey of Saint Gertrude of Leuven. Its main thirteen-bay facade faces the Rue du Duc around the corner, while the address refers to the coach entrance on Rue de la Loi. A lower left wing with a balustraded parapet and a projecting entrance bay with a triangular pediment sits beside a taller rusticated corner block; two flagpoles project from the facade.

Built between 1782 and 1784 by architect Louis Montoyer, the building first served as a refuge for the Abbey of St. Gertrude in Leuven. From 1815 to 1830 it housed the Dutch foreign ministry, and the Belgian state bought it in 1847 for its ministries. In September 1944 Prime Minister Hubert Pierlot moved his offices here from number 18, making it the official seat of government.

The building's name simply refers to its street location, marking its role as part of Brussels' governmental landscape. Passersby notice its subdued presence in a neighborhood closely tied to Belgian political affairs.

The interior of the building is not open to the public, as it functions as an active governmental facility. Visitors can admire the fine architecture and stone facade details from the street while walking through this administrative district.

In 2011, during the long Belgian government formation, a citizens' collective launched "Camping 16", an online call to pitch a virtual tent at number 16 for 100 days; within two weeks the site counted over 140,000 campers. The building's main facade of thirteen bays actually faces the Rue du Duc around the corner, not the Rue de la Loi.