Cannon Courtyard, Washington, D.C.
The Cannon Courtyard is a 300-foot-wide opening at the heart of the oldest congressional office building on the Capitol campus. Thomas Hastings of Carrère and Hastings shaped it to give the building three things: light, air and a natural connection to its landscape. When it opened in 1908, the Court held a circular fountain fifty feet across, set in an open lawn and ringed by a curbed perimeter drive. It survived until 1958, when the whole of it was demolished to build a multilevel parking garage underneath. For the next sixty-seven years, the courtyard was a garage roof. The Cannon Renewal Project, delivered in phases by the Architect of the Capitol, has returned all 70,000 square feet of it to daily use for the first time since the 1950s, with a new fountain at the centre of the original plan.
- Project type
- Institutional
- Urban Development
- Products used
- Location
- Washington, D.C., United States
- Year
- 2025
- Architects
- Shalom Baranes Associates
A courtyard rebuilt on a garage roof
Everything in the renewed courtyard sits on structure. The garage below stayed in service throughout, so a new post-tensioned concrete slab was cast above the existing waffle slab in 2016, transferring load to the columns and walls already in place. The new fountain is smaller than the fifty-foot original for exactly this reason, and its pump, filter and support plant are concealed in the garage beneath it.
Drainage had to work first time. The roofscape this courtyard replaced was known for standing water pooling around failing drains, and the space now carries some 2,000 building occupants through it daily. Weight, water and maintenance access were settled as constraints long before any question of appearance arose.
A drainage ring that reads as carved ornament
Jonite's custom perimeter grates were designed as a continuous decorative band encircling the fountain basin, at the centre of a circular plaza ringed by raised planters, ledge seating and trees. Each unit is cast to the radius of the pool so the circle closes cleanly without faceting, with radial joints that follow the geometry of the plaza rather than interrupting it. The relief is an olive branch, and its leaves and fruit form the drainage apertures themselves, so no separate opening appears anywhere in the ring. An aggregate-exposed surface picks up the tone and texture of the surrounding granite, allowing a working drainage channel to sit within a protected landmark setting as ornament rather than infrastructure.
A concentric grate at the heart of the fountain
At the floor of the basin, a second custom grate handles the main return. Concentric rings of staggered apertures radiate from a plain central disc, holding a considered pattern beneath still water in a pool designed to be read as a reflecting surface for most of its operating life. The staggered arrangement distributes open area evenly across the disc while keeping each aperture narrow, supporting foot traffic during maintenance and keeping debris clear of the return. Above it, three fountain dishes echo the same concentric geometry.
Engineered stone, specified for the long horizon
Both elements were produced in Jonite's reinforced stone and cast to project-specific moulds. The material carries load without a visible metal frame, holds fine relief at the depth the olive motif requires, and resists the corrosion, staining and freeze-thaw cycling that would compromise a metal grate in an open courtyard. A courtyard reopened after sixty-seven years is not one that will be lifted again soon, and every element in it was specified on that basis. The result is a fountain whose drainage is fully present and wholly absorbed into the design, befitting the space the Architect of the Capitol describes as the heart of the building.
Discover custom solutions
Nothing in this courtyard came off a shelf. The perimeter ring was cast to the radius of the basin, its open area set by the olive relief rather than a standard aperture layout. The centre grate was patterned to be read through water and rated to carry foot traffic during maintenance. The surface was matched to the granite around it.
Each of those is a standard part of how we work: custom curves and sizes, open area, patterns and emblems, colours and textures, and tailored load requirements. If your drawings call for something that does not exist yet, that is where we start.
