Central Avenue Constituent Services Center, Los Angeles
Green roof size: 7,585 square feet
Award recipient: Paul Murdoch Architects

Project Team
Civil engineer: RBA/ Mollenhauer
Commissioning consultant: Expedient Energy
Cost estimator: Ciaran P. O'Halloran
Green roof assembly: Henry
Green roof consultant: Rana Creek
Landscape architect: Burton & Company
MEP engineer: IBE Consulting Engineers
Specifications writer: Chew Specifications
Structural engineer: Sato & Boppana

The new Central Avenue Constituent Services Center demonstrates how sustainability integrates social, political, cultural and economic issues within communities. A public roof garden is the first municipal green roof for the City of Los Angeles.

The structure is located in an area of Los Angeles with one of the lowest parkland-to-resident ratios in the city, and an area marked by violence and an extremely low medium-household income. Single and multi-story commercial development along Central Avenue and single and multi-story residential development along the side streets characterize the area. The project’s goal was to create a new space to bring the community together, while providing an educational tool to the public through the visible, architectural expression of environmental innovations.

To give the site a park-like feeling, the design establishes a grid of trees reiforced by the building structure, façade rhythm, and paving pattern. The community features a jazz festival each year to celebrate the history of jazz unique to Central Avenue, and as jazz-like counterpoints, curved and angled walls, stairs, an elevator, and solar panel arrays that track the sun play off the grid’s regular rhythm. The public roof garden is easily accessed from a courtyard, and the plantings can be seen from surrounding streets. The garden provides secure, public, open space, and doubles zoning requirements for open space. The roof garden also demonstrates environmental alternatives in an urban context that mitigate stormwater runoff and heat-island effects, and reduce building energy loads.

The roof garden is planted with over 40 organically grown plant species native to Southern California and adapted to the extreme growing conditions present on an urban roof. Salvias, Agaves, Penstemons, and other flowering natives have been chosen to attract hummingbirds and butterflies. Sedums and fragrant ground covers like rosemary, lavender, and sage blanket the planted beds, and climb over the sides of the building.

Larger shrubs frame the garden and provide seclusion around seating areas. The 12-inch to 18-inch growing medium of scoria, aged compost, peat, sand, and perlite sits on top of a roofing assembly that is built to withstand extreme temperatures. Rainwater runoff from the roof parking area is directed to a custom-designed underground cistern. The water from the cistern is then directed to a drip-irrigation system used for on-site landscaping at the ground level.

Steven W. Peck is the founder and president of Green Roofs for Healthy Cities, the non-profit industry association with a mission to develop the green roof and wall industry across North America. For more information visit greenroofs.org. Readers are invited to join GRFHC at CitiesAlive to meet the award winners and learn more about these outstanding green roof and wall projects: citiesalive.org.